uu.seUppsala University Publications
Change search
Refine search result
1234567 1 - 50 of 372
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Aartsen, M. G.
    et al.
    Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia..
    Abraham, K.
    Tech Univ Munich, D-85748 Garching, Germany..
    Ackermann, M.
    DESY, D-15735 Zeuthen, Germany..
    Adams, J.
    Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand..
    Aguilar, J. A.
    Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium..
    Ahlers, M.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Ahrens, M.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Altmann, D.
    Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany..
    Anderson, T.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Archinger, M.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Arguelles, C.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Arlen, T. C.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Auffenberg, J.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Bai, X.
    South Dakota Sch Mines & Technol, Dept Phys, Rapid City, SD 57701 USA..
    Barwick, S. W.
    Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA..
    Baum, V.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Bay, R.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Beatty, J. J.
    Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.;Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA.;Ohio State Univ, Dept Astron, Columbus, OH 43210 USA..
    Tjus, J. Becker
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Becker, K. -H
    Beiser, E.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    BenZvi, S.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Berghaus, P.
    DESY, D-15735 Zeuthen, Germany..
    Berley, D.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Bernardini, E.
    DESY, D-15735 Zeuthen, Germany..
    Bernhard, A.
    Tech Univ Munich, D-85748 Garching, Germany..
    Besson, D. Z.
    Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA..
    Binder, G.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.;Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Bindig, D.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Bissok, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Blaufuss, E.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Blumenthal, J.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Boersma, David J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Bohm, C.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Boerner, M.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Bos, F.
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Bose, D.
    Sungkyunkwan Univ, Dept Phys, Suwon 440 746, South Korea..
    Boeser, S.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Botner, Olga
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Braun, J.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Brayeur, L.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Bretz, H. -P
    Brown, A. M.
    Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand..
    Buzinsky, N.
    Univ Alberta, Dept Phys, Edmonton, AB T6G 2E1, Canada..
    Casey, J.
    Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA.;Georgia Inst Technol, Ctr Relativist Astrophys, Atlanta, GA 30332 USA..
    Casier, M.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Cheung, E.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Chirkin, D.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Christov, A.
    Univ Geneva, Dept phys nucl & corpusculaire, CH-1211 Geneva, Switzerland..
    Christy, B.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Clark, K.
    Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada..
    Classen, L.
    Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany..
    Coenders, S.
    Tech Univ Munich, D-85748 Garching, Germany..
    Cowen, D. F.
    Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA.;Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Silva, A. H. Cruz
    DESY, D-15735 Zeuthen, Germany..
    Daughhetee, J.
    Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA.;Georgia Inst Technol, Ctr Relativist Astrophys, Atlanta, GA 30332 USA..
    Davis, J. C.
    Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.;Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA..
    Day, M.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    de Andre, J. P. A. M.
    Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA..
    De Clercq, C.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Dembinski, H.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    De Ridder, S.
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Desiati, P.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    de Vries, K. D.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    de Wasseige, G.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    de With, M.
    Humboldt Univ, D-12489 Berlin, Germany..
    DeYoung, T.
    Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA..
    Diaz-Velez, J. C.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Dumm, J. P.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Dunkman, M.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Eagan, R.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Eberhardt, B.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Ehrhardt, T.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Eichmann, B.
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Euler, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Evenson, P. A.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Fadiran, O.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Fahey, S.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Fazely, A. R.
    Southern Univ, Dept Phys, Baton Rouge, LA 70813 USA..
    Fedynitch, A.
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Feintzeig, J.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Felde, J.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Filimonov, K.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Finley, C.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Fischer-Wasels, T.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Flis, S.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Fuchs, T.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Glagla, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Gaisser, T. K.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Gaior, R.
    Chiba Univ, Dept Phys, Chiba 2638522, Japan..
    Gallagher, J.
    Univ Wisconsin, Dept Astron, Madison, WI 53706 USA..
    Gerhardt, L.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.;Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Ghorbani, K.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Gier, D.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Gladstone, L.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Gluesenkamp, T.
    DESY, D-15735 Zeuthen, Germany..
    Goldschmidt, A.
    Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Golup, G.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Gonzalez, J. G.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Gora, D.
    DESY, D-15735 Zeuthen, Germany..
    Grant, D.
    Univ Alberta, Dept Phys, Edmonton, AB T6G 2E1, Canada..
    Gretskov, P.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Groh, J. C.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Gross, A.
    Tech Univ Munich, D-85748 Garching, Germany..
    Ha, C.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.;Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Haack, C.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Ismail, A. Haj
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Hallgren, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Halzen, F.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Hansmann, B.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Hanson, K.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Hebecker, D.
    Humboldt Univ, D-12489 Berlin, Germany..
    Heereman, D.
    Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium..
    Helbing, K.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Hellauer, R.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Hellwig, D.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Hickford, S.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Hignight, J.
    Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA..
    Hill, G. C.
    Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia..
    Hoffman, K. D.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Hoffmann, R.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Holzapfel, K.
    Tech Univ Munich, D-85748 Garching, Germany..
    Homeier, A.
    Univ Bonn, Inst Phys, D-53115 Bonn, Germany..
    Hoshina, K.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Huang, F.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Huber, M.
    Tech Univ Munich, D-85748 Garching, Germany..
    Huelsnitz, W.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Hulth, P. O.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Hultqvist, K.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    In, S.
    Sungkyunkwan Univ, Dept Phys, Suwon 440 746, South Korea..
    Ishihara, A.
    Chiba Univ, Dept Phys, Chiba 2638522, Japan..
    Jacobi, E.
    DESY, D-15735 Zeuthen, Germany..
    Japaridze, G. S.
    Clark Atlanta Univ, CTSPS, Atlanta, GA 30314 USA..
    Jero, K.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Jurkovic, M.
    Tech Univ Munich, D-85748 Garching, Germany..
    Kaminsky, B.
    DESY, D-15735 Zeuthen, Germany..
    Kappes, A.
    Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany..
    Karg, T.
    DESY, D-15735 Zeuthen, Germany..
    Karle, A.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Kauer, M.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA.;Yale Univ, Dept Phys, New Haven, CT 06520 USA..
    Keivani, A.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Kelley, J. L.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Kemp, J.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Kheirandish, A.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Kiryluk, J.
    SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA..
    Klaes, J.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Klein, S. R.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.;Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Kohnen, G.
    Univ Mons, B-7000 Mons, Belgium..
    Kolanoski, H.
    Humboldt Univ, D-12489 Berlin, Germany..
    Konietz, R.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Koob, A.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Koepke, L.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Kopper, C.
    Univ Alberta, Dept Phys, Edmonton, AB T6G 2E1, Canada..
    Kopper, S.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany.;DESY, D-15735 Zeuthen, Germany..
    Koskinen, D. J.
    Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark..
    Kowalski, M.
    Humboldt Univ, D-12489 Berlin, Germany..
    Krings, K.
    Tech Univ Munich, D-85748 Garching, Germany..
    Kroll, G.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Kroll, M.
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Kunnen, J.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Kurahashi, N.
    Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA..
    Kuwabara, T.
    Chiba Univ, Dept Phys, Chiba 2638522, Japan..
    Labare, M.
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Lanfranchi, J. L.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Larson, M. J.
    Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark..
    Lesiak-Bzdak, M.
    SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA..
    Leuermann, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Leuner, J.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Luenemann, J.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Madsen, J.
    Univ Wisconsin, Dept Phys, River Falls, WI 54022 USA..
    Maggi, G.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Mahn, K. B. M.
    Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA..
    Maruyama, R.
    Yale Univ, Dept Phys, New Haven, CT 06520 USA..
    Mase, K.
    Chiba Univ, Dept Phys, Chiba 2638522, Japan..
    Matis, H. S.
    Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Maunu, R.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    McNally, F.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Meagher, K.
    Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium..
    Medici, M.
    Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark..
    Meli, A.
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Menne, T.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Merino, G.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Meures, T.
    Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium..
    Miarecki, S.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.;Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Middell, E.
    DESY, D-15735 Zeuthen, Germany..
    Middlemas, E.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Miller, J.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Mohrmann, L.
    DESY, D-15735 Zeuthen, Germany..
    Montaruli, T.
    Univ Geneva, Dept phys nucl & corpusculaire, CH-1211 Geneva, Switzerland..
    Morse, R.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Nahnhauer, R.
    DESY, D-15735 Zeuthen, Germany..
    Naumann, U.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Niederhausen, H.
    SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA..
    Nowicki, S. C.
    Univ Alberta, Dept Phys, Edmonton, AB T6G 2E1, Canada..
    Nygren, D. R.
    Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Obertacke, A.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Olivas, A.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Omairat, A.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    O'Murchadha, A.
    Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium..
    Palczewski, T.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    Paul, L.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Pepper, J. A.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    de los Heros, Carlos. Perez
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Pfendner, C.
    Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.;Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA..
    Pieloth, D.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Pinat, E.
    Univ Libre Bruxelles, Fac Sci, B-1050 Brussels, Belgium..
    Posselt, J.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Price, P. B.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Przybylski, G. T.
    Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Puetz, J.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Quinnan, M.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Raedel, L.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Rameez, M.
    Univ Geneva, Dept phys nucl & corpusculaire, CH-1211 Geneva, Switzerland..
    Rawlins, K.
    Univ Alaska Anchorage, Dept Phys & Astron, Anchorage, AK 99508 USA..
    Redl, P.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Reimann, R.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Relich, M.
    Chiba Univ, Dept Phys, Chiba 2638522, Japan..
    Resconi, E.
    Tech Univ Munich, D-85748 Garching, Germany..
    Rhode, W.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Richman, M.
    Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA..
    Richter, S.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Riedel, B.
    Univ Alberta, Dept Phys, Edmonton, AB T6G 2E1, Canada..
    Robertson, S.
    Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia..
    Rongen, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Rott, C.
    Sungkyunkwan Univ, Dept Phys, Suwon 440 746, South Korea..
    Ruhe, T.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Ruzybayev, B.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Ryckbosch, D.
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Saba, S. M.
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Sabbatini, L.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Sander, H. -G
    Sandrock, A.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Sandroos, J.
    Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark..
    Sarkar, S.
    Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark.;Univ Oxford, Dept Phys, Oxford OX1 3NP, England..
    Schatto, K.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Scheriau, F.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Schimp, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Schmidt, T.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Schmitz, M.
    TU Dortmund Univ, Dept Phys, D-44221 Dortmund, Germany..
    Schoenen, S.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Schoeneberg, S.
    Ruhr Univ Bochum, Fak Phys & Astron, D-44780 Bochum, Germany..
    Schoenwald, A.
    DESY, D-15735 Zeuthen, Germany..
    Schukraft, A.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Schulte, L.
    Univ Bonn, Inst Phys, D-53115 Bonn, Germany..
    Seckel, D.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Seunarine, S.
    Univ Wisconsin, Dept Phys, River Falls, WI 54022 USA..
    Shanidze, R.
    DESY, D-15735 Zeuthen, Germany..
    Smith, M. W. E.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Soldin, D.
    Univ Wuppertal, Dept Phys, D-42119 Wuppertal, Germany..
    Spiczak, G. M.
    Univ Wisconsin, Dept Phys, River Falls, WI 54022 USA..
    Spiering, C.
    DESY, D-15735 Zeuthen, Germany..
    Stahlberg, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Stamatikos, M.
    Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.;Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA..
    Stanev, T.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Stanisha, N. A.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Stasik, A.
    DESY, D-15735 Zeuthen, Germany..
    Stezelberger, T.
    Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Stokstad, R. G.
    Lawrence Berkeley Natl Lab, Berkeley, CA USA..
    Stoessl, A.
    DESY, D-15735 Zeuthen, Germany..
    Strahler, E. A.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Ström, Richard
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Strotjohann, N. L.
    DESY, D-15735 Zeuthen, Germany..
    Sullivan, G. W.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Sutherland, M.
    Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.;Ohio State Univ, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA..
    Taavola, Henric
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Taboada, I.
    Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA.;Georgia Inst Technol, Ctr Relativist Astrophys, Atlanta, GA 30332 USA..
    Ter-Antonyan, S.
    Southern Univ, Dept Phys, Baton Rouge, LA 70813 USA..
    Terliuk, A.
    DESY, D-15735 Zeuthen, Germany..
    Tesic, G.
    Penn State Univ, Dept Phys, University Pk, PA 16802 USA..
    Tilav, S.
    Univ Delaware, Bartol Res Inst, Dept Phys & Astron, Newark, DE 19716 USA..
    Toale, P. A.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    Tobin, M. N.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Tosi, D.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Tselengidou, M.
    Univ Erlangen Nurnberg, Erlangen Ctr Astroparticle Phys, D-91058 Erlangen, Germany..
    Unger, E.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Usner, M.
    DESY, D-15735 Zeuthen, Germany..
    Vallecorsa, S.
    Univ Geneva, Dept phys nucl & corpusculaire, CH-1211 Geneva, Switzerland..
    van Eijndhoven, N.
    Vrije Univ Brussel, Dienst ELEM, Brussels, Belgium..
    Vandenbroucke, J.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    van Santen, J.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Vanheule, S.
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Veenkamp, J.
    Tech Univ Munich, D-85748 Garching, Germany..
    Vehring, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Voge, M.
    Univ Bonn, Inst Phys, D-53115 Bonn, Germany..
    Vraeghe, M.
    Univ Ghent, Dept Phys & Astron, B-9000 Ghent, Belgium..
    Walck, C.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Wallraff, M.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Wandkowsky, N.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Weaver, Ch.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Wendt, C.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Westerhoff, S.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Whelan, B. J.
    Univ Adelaide, Sch Chem & Phys, Adelaide, SA 5005, Australia..
    Whitehorn, N.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Wichary, C.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Wiebe, K.
    Johannes Gutenberg Univ Mainz, Inst Phys, D-55099 Mainz, Germany..
    Wiebusch, C. H.
    Rhein Westfal TH Aachen, Inst Phys 3, D-52056 Aachen, Germany..
    Wille, L.
    Univ Wisconsin, Dept Phys, Wisconsin IceCube Particle Astrophys Ctr, Madison, WI 53706 USA..
    Williams, D. R.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    Wissing, H.
    Univ Maryland, Dept Phys, College Pk, MD 20742 USA..
    Wolf, M.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Wood, T. R.
    Univ Alberta, Dept Phys, Edmonton, AB T6G 2E1, Canada..
    Woschnagg, K.
    Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA..
    Xu, D. L.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    Xu, X. W.
    Southern Univ, Dept Phys, Baton Rouge, LA 70813 USA..
    Xu, Y.
    SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA..
    Yanez, J. P.
    DESY, D-15735 Zeuthen, Germany..
    Yodh, G.
    Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA..
    Yoshida, S.
    Chiba Univ, Dept Phys, Chiba 2638522, Japan..
    Zarzhitsky, P.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    Zoll, M.
    Univ Stockholm, Dept Phys, Oskar Klein Ctr, S-10691 Stockholm, Sweden..
    Search for dark matter annihilation in the Galactic Center with IceCube-792015In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 75, no 10, article id 492Article in journal (Refereed)
    Abstract [en]

    The Milky Way is expected to be embedded in a halo of dark matter particles, with the highest density in the central region, and decreasing density with the halo-centric radius. Dark matter might be indirectly detectable at Earth through a flux of stable particles generated in dark matter annihilations and peaked in the direction of the Galactic Center. We present a search for an excess flux of muon (anti-) neutrinos from dark matter annihilation in the Galactic Center using the cubic-kilometer-sized IceCube neutrino detector at the South Pole. There, the Galactic Center is always seen above the horizon. Thus, new and dedicated veto techniques against atmospheric muons are required to make the southern hemisphere accessible for IceCube. We used 319.7 live-days of data from IceCube operating in its 79-string configuration during 2010 and 2011. No neutrino excess was found and the final result is compatible with the background. We present upper limits on the self-annihilation cross-section, < sAv >, for WIMP masses ranging from 30GeV up to 10TeV, assuming cuspy (NFW) and flat-cored (Burkert) dark matter halo profiles, reaching down to similar or equal to 4 . 10(-24) cm(3) s(-1), and similar or equal to 2.6 . 10(-23) cm(3) s(-1) for the nu(nu) over bar channel, respectively.

  • 2.
    Aiempanakit, Montri
    et al.
    Linkoping University.
    Aijaz, Asim
    Linkoping University.
    Helmersson, Ulf
    Linkoping University.
    Kubart, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Hysteresis effect in reactive high power impulse magnetron sputtering of metal oxides2011Conference paper (Refereed)
    Abstract [en]

    In order to get high deposition rate and good film properties, the stabilization of the transition zone between the metallic and compound modes is beneficial. We have shown earlier that at least in some cases, HiPIMS can reduce hysteresis effect in reactive sputtering. In our previous work, mechanisms for the suppression/elimination of the hysteresis effect have been suggested. Reactive HiPIMS can suppress/eliminate the hysteresis effect in the range of optimum frequency [1] lead to the process stability during the deposition with high deposition rate. The mechanisms behind this optimum frequency may relate with high erosion rate during the pulse [2,3] and gas rarefaction effect in front of the target [4]. 

     

    In this contribution, reactive sputtering process using high power impulse magnetron sputtering (HiPIMS) has been studied with focus on the gas rarefaction. Through variations in the sputtering conditions such as pulse frequencies, peak powers, and target area, their effect on the shape of current waveforms have been analyzed. The current waveforms in compound mode are strongly affected. Our experiments show that the shape and amplitude of peak current cannot be explained by the change of the secondary electron yield due to target oxidation only. Reduced rarefaction in compound mode contributes to the observed very high peak current values.

  • 3.
    Aikio, A. T.
    et al.
    Univ Oulu, Ionospher Phys Unit, Oulu, Finland.
    Vanhamaeki, H.
    Kyushu Univ, Int Ctr Space Weather Sci & Educ, Fukuoka, Japan;Univ Oulu, Ionospher Phys Unit, Oulu, Finland.
    Workayehu, A. B.
    Univ Oulu, Ionospher Phys Unit, Oulu, Finland.
    Virtanen, I. I.
    Univ Oulu, Ionospher Phys Unit, Oulu, Finland.
    Kauristie, K.
    Finnish Meteorol Inst, Helsinki, Finland.
    Juusola, L.
    Finnish Meteorol Inst, Helsinki, Finland.
    Buchert, Stephan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Knudsen, D.
    Univ Calgary, Dept Phys & Astron, Calgary, AB, Canada.
    Swarm Satellite and EISCAT Radar Observations of a Plasma Flow Channel in the Auroral Oval Near Magnetic Midnight2018In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, no 6, p. 5140-5158Article in journal (Refereed)
    Abstract [en]

    We present Swarm satellite and EISCAT radar observations of electrodynamical parameters in the midnight sector at high latitudes. The most striking feature is a plasma flow channel located equatorward of the polar cap boundary within the dawn convection cell. The flow channel is 1.5 degrees wide in latitude and contains southward electric field of 150 mV/m, corresponding to eastward plasma velocities of 3,300 m/s in the F-region ionosphere. The theoretically computed ion temperature enhancement produced by the observed ion velocity is in accordance with the measured one by the EISCAT radar. The total width of the auroral oval is about 10 degrees in latitude. While the poleward part is electric field dominant with low conductivity and the flow channel, the equatorward part is conductivity dominant with at least five auroral arcs. The main part of the westward electrojet flows in the conductivity dominant part, but it extends to the electric field dominant part. According to Kamide and Kokubun (1996), the whole midnight sector westward electrojet is expected to be conductivity dominant, so the studied event challenges the traditional view. The flow channel is observed after substorm onset. We suggest that the observed flow channel, which is associated with a 13-kV horizontal potential difference, accommodates increased nightside plasma flows during the substorm expansion phase as a result of reconnection in the near-Earth magnetotail.

  • 4.
    Al Moulla, Khaled
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Turbulence at MHD and sub-ion scales in the magnetosheath of Saturn: a comparative study between quasi-perpendicular and quasi-parallel bow shocks using in-situ Cassini data2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project is to investigate the spectral properties of turbulence in the magnetosheath of Saturn, using in-situ magnetic field measurements from the Cassini spacecraft. According to models of incompressible, turbulent fluids, the energy spectrum in the inertial range scales as the frequency to the power of -5/3, which has been observed in the near-Earth Solar wind but not in the Terrestrial magnetosheath unless close to the magnetopause. 120 time intervals for when Cassini is inside the magnetosheath are identified — 40 in each category of behind quasi-perpendicular bow shocks, behind quasi-parallel bow shocks, and inside the middle of the magnetosheath. The power spectral density is thereafter calculated for each interval, with logarithmic regressions performed at the MHD and sub-ion scales separated by the ion gyrofrequency. The results seem to indicate similar behaviour as in the magnetosheath of Earth, without significant difference between quasi-perpendicular and quasi-parallel cases except somewhat steeper exponents at the MHD scale for the former. These observations confirm the role of the bow shock in destroying the fully developed turbulence of the Solar wind, thus explaining the absence of the inertial range.

  • 5.
    Ala-Lahti, Matti M.
    et al.
    Univ Helsinki, Dept Phys, POB 64, Helsinki, Finland.
    Kilpua, Emilia K. J.
    Univ Helsinki, Dept Phys, POB 64, Helsinki, Finland.
    Dimmock, Andrew P.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division. Aalto Univ, Sch Elect Engn, Espoo, Finland.
    Osmane, Adnane
    Aalto Univ, Sch Elect Engn, Espoo, Finland.
    Pulkkinen, Tuija
    Aalto Univ, Sch Elect Engn, Espoo, Finland.
    Soucek, Jan
    Czech Acad Sci, Inst Atmospher Phys, Prague, Czech Republic.
    Statistical analysis of mirror mode waves in sheath regions driven by interplanetary coronal mass ejection2018In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 36, no 3, p. 793-808Article in journal (Refereed)
    Abstract [en]

    We present a comprehensive statistical analysis of mirror mode waves and the properties of their plasma surroundings in sheath regions driven by interplanetary coronal mass ejection (ICME). We have constructed a semi-automated method to identify mirror modes from the magnetic field data. We analyze 91 ICME sheath regions from January 1997 to April 2015 using data from the Wind spacecraft. The results imply that similarly to planetary magnetosheaths, mirror modes are also common structures in ICME sheaths. However, they occur almost exclusively as dip-like structures and in mirror stable plasma. We observe mirror modes throughout the sheath, from the bow shock to the ICME leading edge, but their amplitudes are largest closest to the shock. We also find that the shock strength (measured by Alfven Mach number) is the most important parameter in controlling the occurrence of mirror modes. Our findings suggest that in ICME sheaths the dominant source of free energy for mirror mode generation is the shock compression. We also suggest that mirror modes that are found deeper in the sheath are remnants from earlier times of the sheath evolution, generated also in the vicinity of the shock.

  • 6.
    Alinder, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Effect of the convective electric field on the ion number density around a low activity comet2017Student paper other, 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    Vigren et al. (2015) presents an integral expression to calculate the ion number density around a low activity comet immersed in the solar wind's convective electric field. A certain parameter of the integral takes values of either 1 or 0 depending on whether a corresponding ion trajectory is feasible or not. The criteria used in the paper has been found not to be strict enough, yielding overestimated ion number densities in the cometary wake. The present project finds two new options for the criteria, one analytical and one numerical. The new numerical condition is tested in the same computations done in the original paper and compares the results of the old and new criteria. The new conditionis found to correct the previous error.

  • 7.
    Alinder, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Electron cooling in a cometary coma2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The ESA Rosetta spacecraft investigated comet 67P/Churyumov-Gerasimenko duringtwo years from August 2014 to the end of September 2016. The dual Langmuir probewas used to measure plasma parameters including the thermal energy of theelectrons. The observed thermal energy (or temperature) of the electrons was ratherhigh, in the range 5-10 eV almost throughout the mission. However, near perihelionthe Langmuir probe measurements indicated the prevalence of two electronpopulations with distinct temperatures, one hot (5-10 eV) and one cold (less than 1eV). It has been hypothesized that the electrons of the colder population wereformed relatively close to the nucleus and that they subsequently cooled by inelasticcollisions with the neutral gas. In this project work we develop a model for studyingelectron cooling in a cometary coma. The model takes into account collisions withwater molecules as well as the influence of a radial ambipolar electric field.

  • 8.
    Allen, R. C.
    et al.
    Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA..
    Zhang, J. -C
    Kistler, L. M.
    Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA..
    Spence, H. E.
    Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA..
    Lin, R. -L
    Klecker, B.
    Max Planck Inst Extraterr Phys, D-85748 Garching, Germany..
    Dunlop, M. W.
    Rutherford Appleton Lab, Div Space Sci, Harwell, Oxon, England..
    André, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Jordanova, V. K.
    Los Alamos Natl Lab, Los Alamos, NM USA..
    A statistical study of EMIC waves observed by Cluster: 1. Wave properties2015In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 120, no 7, p. 5574-5592Article in journal (Refereed)
    Abstract [en]

    Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In this study, we present a statistical analysis of EMIC wave properties using 10years (2001-2010) of data from Cluster, totaling 25,431min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. The statistical analysis is presented in two papers. This paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

  • 9.
    Alm, L.
    et al.
    Univ New Hampshire, Space Sci Ctr, Durham, NH 03824 USA..
    Argall, M. R.
    Univ New Hampshire, Space Sci Ctr, Durham, NH 03824 USA..
    Torbert, R. B.
    Univ New Hampshire, Space Sci Ctr, Durham, NH 03824 USA.;Southwest Res Inst, San Antonio, TX USA..
    Farrugia, C. J.
    Univ New Hampshire, Space Sci Ctr, Durham, NH 03824 USA..
    Burch, J. L.
    Southwest Res Inst, San Antonio, TX USA..
    Ergun, R. E.
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
    Russell, C. T.
    Univ Calif Los Angeles, IGPP EPSS, Los Angeles, CA USA..
    Strangeway, R. J.
    Univ Calif Los Angeles, IGPP EPSS, Los Angeles, CA USA..
    Khotyaintsev, Yuri V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Lindqvist, P. -A
    Marklund, G. T.
    KTH Royal Inst Technol, Stockholm, Sweden..
    Giles, B. L.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA..
    Shuster, J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.;Univ Maryland, Coll Comp Math & Nat Sci, College Pk, MD 20742 USA..
    EDR signatures observed by MMS in the 16 October event presented in a 2-D parametric space2017In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 122, no 3, p. 3262-3276Article in journal (Refereed)
    Abstract [en]

    We present a method for mapping the position of satellites relative to the X line using the measured B-L and B-N components of the magnetic field and apply it to the Magnetospheric multiscale (MMS) encounter with the electron diffusion region (EDR) which occurred on 13:07 UT on 16 October 2015. Mapping the data to our parametric space succeeds in capturing many of the signatures associated with magnetic reconnection and the electron diffusion region. This offers a method for determining where in the reconnection region the satellites were located. In addition, parametric mapping can also be used to present data from numerical simulations. This facilitates comparing data from simulations with data from in situ observations as one can avoid the complicated process using boundary motion analysis to determine the geometry of the reconnection region. In parametric space we can identify the EDR based on the collocation of several reconnection signatures, such as electron nongyrotropy, electron demagnetization, parallel electric fields, and energy dissipation. The EDR extends 2-3km in the normal direction and in excess of 20km in the tangential direction. It is clear that the EDR occurs on the magnetospheric side of the topological X line, which is expected in asymmetric reconnection. Furthermore, we can observe a north-south asymmetry, where the EDR occurs north of the peak in out-of-plane current, which may be due to the small but finite guide field.

  • 10. Andersson, Ludvig
    et al.
    Rasouli, Karwan
    Modeling fuel ion orbits during sawtooth instabilities in fusion plasmas2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An important part of the fusion research program is to understand and control the large number of plasma instabilities that a fusion plasma can exhibit. One such instability is known as the “sawtooth” instability, which is a perturbation in the plasma electric and magnetic fields that manifests itself as periodic relaxations of the temperature and density in the plasma center.

    The aim of this project was to investigate how the fuel ions in a fusion plasma react to the sawtooth instability.

    We were able to implement a model of the plasma electromagnetic field during a sawtooth relaxation into an existing code that computes the orbits of the fuel ions in the tokamak magnetic field. To this end, it was necessary to modify the orbit code to allow for non-zero electric fields, and for time-varying fields. In order to validate the new additions to the code, we compared simulated results to analytical ones.

    The model of the sawtooth electromagnetic fields required for our simulations was set up within a different student project. However, due to unforeseen complications, only the magnetic (not the electric) field contribution was available to us during our project, but once the electric field is available it is straightforward to include in our code.

    Our simulations did not exhibit any noticeable perturbation to the particle orbit during a sawtooth crash. However, before the electric field contribution is included it is not possible to draw any physics conclusions from these results. Our code could also be used as a foundation for future projects since it is possible (with further implementations to the existing code) to simulate how the spatial profile of the neutron emission is expected to vary during the sawtooth. These simulations can be compared against experimental measurements of the neutron emission profile in order to investigate the accuracy of the sawtooth model under consideration.

  • 11.
    Andreasson, Jakob
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Timneanu, Nicusor
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Iwan, Bianca
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Hantke, Max
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Rath, Asawari
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Ekeberg, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Maia, Filipe R. N. C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Barty, Anton
    Chapman, Henry N.
    Bielecki, Johan
    Abergel, C.
    Seltzer, V.
    Claverie, J.-M.
    Svenda, M.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Hajdu, Janos
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Time of Flight Mass Spectrometry to Monitor Sample Expansion in Flash Diffraction Studies on Single Virus ParticlesManuscript (preprint) (Other academic)
  • 12.
    Andres, N.
    et al.
    Univ Paris Sud, Sorbonne Univ, Lab Phys Plasmas, CNRS,Ecole Polytech,Observ Paris, F-91128 Palaiseau, France.
    Sahraoui, F.
    Univ Paris Sud, Sorbonne Univ, Lab Phys Plasmas, CNRS,Ecole Polytech,Observ Paris, F-91128 Palaiseau, France.
    Galtier, S.
    Univ Paris Sud, Sorbonne Univ, Lab Phys Plasmas, CNRS,Ecole Polytech,Observ Paris, F-91128 Palaiseau, France;Univ Paris Saclay, Univ Paris Sud, Paris, France.
    Hadid, Lina Z
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Dmitruk, P.
    UBA, CONICET, Inst Fis Buenos Aires, Ciudad Univ, RA-1428 Buenos Aires, DF, Argentina.
    Mininni, P. D.
    Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Fis, Ciudad Univ, RA-1428 Buenos Aires, DF, Argentina.
    Energy cascade rate in isothermal compressible magnetohydrodynamic turbulence2018In: Journal of Plasma Physics, ISSN 0022-3778, E-ISSN 1469-7807, Vol. 84, no 4, article id 905840404Article in journal (Refereed)
    Abstract [en]

    Three-dimensional direct numerical simulations are used to study the energy cascade rate in isothermal compressible magnetohydrodynamic turbulence. Our analysis is guided by a two-point exact law derived recently for this problem in which flux, source, hybrid and mixed terms are present. The relative importance of each term is studied for different initial subsonic Mach numbers M-S and different magnetic guide fields B-0. The dominant contribution to the energy cascade rate comes from the compressible flux, which depends weakly on the magnetic guide field B-0, unlike the other terms whose moduli increase significantly with M s and B-0. In particular, for strong B-0 the source and hybrid terms are dominant at small scales with almost the same amplitude but with a different sign. A statistical analysis undertaken with an isotropic decomposition based on the SO(3) rotation group is shown to generate spurious results in the presence of B-0, when compared with an axisymmetric decomposition better suited to the geometry of the problem. Our numerical results are compared with previous analyses made with in situ measurements in the solar wind and the terrestrial magnetosheath.

  • 13.
    Andrews, David J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Andersson, L.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    Delory, G. T.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Ergun, R. E.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    Eriksson, Anders I.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Fowler, C. M.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    McEnulty, T.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    Morooka, M. W.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    Weber, T.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    Jakosky, B. M.
    Lab Atmospher & Space Phys, Boulder, CO USA..
    Ionospheric plasma density variations observed at Mars by MAVEN/LPW2015In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 42, no 21, p. 8862-8869Article in journal (Refereed)
    Abstract [en]

    We report on initial observations made by the Langmuir Probe and Waves relaxation sounding experiment on board the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. These measurements yield the ionospheric thermal plasma density, and we use these data here for an initial survey of its variability. Studying orbit-to-orbit variations, we show that the relative variability of the ionospheric plasma density is lowest at low altitudes near the photochemical peak, steadily increases toward higher altitudes and sharply increases as the spacecraft crosses the terminator and moves into the nightside. Finally, despite the small volume of data currently available, we show that a clear signature of the influence of crustal magnetic fields on the thermal plasma density fluctuations is visible. Such results are consistent with previously reported remote measurements made at higher altitudes, but crucially, here we sample a new span of altitudes between similar to 130 and similar to 300 km using in situ techniques.

  • 14.
    Andrews, David J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    André, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Opgenoorth, Hermann J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Edberg, Niklas J. T.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Dieval, C.
    Duru, F.
    Gurnett, D. A.
    Morgan, D.
    Witasse, O.
    Oblique reflections in the Mars Express MARSIS data set: Stable density structures in the Martian ionosphere2014In: Journal of Geophysical Research-Space Physics, ISSN 2169-9380, Vol. 119, no 5, p. 3944-3960Article in journal (Refereed)
    Abstract [en]

    The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) onboard the European Space Agency's Mars Express (MEX) spacecraft routinely detects evidence of localized plasma density structures in the Martian dayside ionosphere. Such structures, likely taking the form of spatially extended elevations in the plasma density at a given altitude, give rise to oblique reflections in the Active Ionospheric Sounder data. These structures are likely related to the highly varied Martian crustal magnetic field. In this study we use the polar orbit of MEX to investigate the repeatability of the ionospheric structures producing these anomalous reflections, examining data taken in sequences of multiple orbits which pass over the same regions of the Martian surface under similar solar illuminations, within intervals lasting tens of days. Presenting three such examples, or case studies, we show for the first time that these oblique reflections are often incredibly stable, indicating that the underlying ionospheric structures are reliably reformed in the same locations and with qualitatively similar parameters. The visibility, or lack thereof, of a given oblique reflection on a single orbit can generally be attributed to variations in the crustal field within the ionosphere along the spacecraft trajectory. We show that, within these examples, oblique reflections are generally detected whenever the spacecraft passes over regions of intense near-radial crustal magnetic fields (i.e., with a cusp-like configuration). The apparent stability of these structures is an important feature that must be accounted for in models of their origin.

  • 15.
    Andrews, David J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Opgenoorth, Hermann J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Leyser, Thomas B.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Buchert, Stephan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Edberg, Niklas J. T.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Morgan, D. D.
    Univ Iowa, Dept Phys & Astron, Iowa City, IA USA.
    Gurnett, D. A.
    Univ Iowa, Dept Phys & Astron, Iowa City, IA USA.
    Kopf, A. J.
    Univ Iowa, Dept Phys & Astron, Iowa City, IA USA.
    Fallows, K.
    Boston Univ, Ctr Space Phys, Boston, MA USA.
    Withers, P.
    Boston Univ, Ctr Space Phys, Boston, MA USA; Boston Univ, Dept Astron, Commonwealth Ave, Boston, MA USA.
    MARSIS Observations of Field-Aligned Irregularities and Ducted Radio Propagation in the Martian Ionosphere2018In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, no 8, p. 6251-6263Article in journal (Refereed)
    Abstract [en]

    Knowledge of Mars's ionosphere has been significantly advanced in recent years by observations from Mars Express and lately Mars Atmosphere and Volatile EvolutioN. A topic of particular interest are the interactions between the planet's ionospheric plasma and its highly structured crustal magnetic fields and how these lead to the redistribution of plasma and affect the propagation of radio waves in the system. In this paper, we elucidate a possible relationship between two anomalous radar signatures previously reported in observations from the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument on Mars Express. Relatively uncommon observations of localized, extreme increases in the ionospheric peak density in regions of radial (cusp-like) magnetic fields and spread echo radar signatures are shown to be coincident with ducting of the same radar pulses at higher altitudes on the same field lines. We suggest that these two observations are both caused by a high electric field (perpendicular to B) having distinctly different effects in two altitude regimes. At lower altitudes, where ions are demagnetized and electrons magnetized, and recombination dominantes, a high electric field causes irregularities, plasma turbulence, electron heating, slower recombination, and ultimately enhanced plasma densities. However, at higher altitudes, where both ions and electrons are magnetized and atomic oxygen ions cannot recombine directly, the high electric field instead causes frictional heating, a faster production of molecular ions by charge exchange, and so a density decrease. The latter enables ducting of radar pulses on closed field lines, in an analogous fashion to interhemispheric ducting in the Earth's ionosphere.

  • 16.
    Andriopoulou, M.
    et al.
    Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria..
    Nakamura, R.
    Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria..
    Torkar, K.
    Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria..
    Baumjohann, W.
    Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria..
    Torbert, R. B.
    Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA..
    Lindqvist, P. -A
    Khotyaintsev, Yuri V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Dorelli, J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Burch, J. L.
    SW Res Inst, San Antonio, TX USA..
    Russell, C. T.
    Univ Calif Los Angeles, Dept Earth Planetary & Space Sci, Los Angeles, CA USA..
    Study of the spacecraft potential under active control and plasma density estimates during the MMS commissioning phase2016In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 43, no 10, p. 4858-4864Article in journal (Refereed)
    Abstract [en]

    Each spacecraft of the recently launched magnetospheric multiscale MMS mission is equipped with Active Spacecraft Potential Control (ASPOC) instruments, which control the spacecraft potential in order to reduce spacecraft charging effects. ASPOC typically reduces the spacecraft potential to a few volts. On several occasions during the commissioning phase of the mission, the ASPOC instruments were operating only on one spacecraft at a time. Taking advantage of such intervals, we derive photoelectron curves and also perform reconstructions of the uncontrolled spacecraft potential for the spacecraft with active control and estimate the electron plasma density during those periods. We also establish the criteria under which our methods can be applied.

  • 17.
    Andriopoulou, Maria
    et al.
    Austrian Acad Sci, Space Res Inst, Graz, Austria.
    Nakamura, Rumi
    Austrian Acad Sci, Space Res Inst, Graz, Austria.
    Wellenzohn, Simon
    Karl Franzens Univ Graz, Inst Geophys Astrophys & Meteorol, Graz, Austria.
    Torkar, Klaus
    Austrian Acad Sci, Space Res Inst, Graz, Austria.
    Baumjohann, Wolfgang
    Austrian Acad Sci, Space Res Inst, Graz, Austria.
    Torbert, R. B.
    Univ New Hampshire, Dept Phys, Durham, NH 03824 USA;Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA.
    Lindqvist, Per-Arne
    KTH Royal Inst Technol, Dept Space & Plasma Phys, Stockholm, Sweden.
    Khotyaintsev, Yuri V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Dorelli, John
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Burch, James L.
    Southwest Res Inst, San Antonio, TX USA.
    Plasma Density Estimates From Spacecraft Potential Using MMS Observations in the Dayside Magnetosphere2018In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, no 4, p. 2620-2629Article in journal (Refereed)
    Abstract [en]

    Using spacecraft potential observations with and without active spacecraft potential control (on/off) from the Magnetospheric Multiscale (MMS) mission, we estimate the average photoelectron emission as well as derive the plasma density information from spacecraft potential variations and active spacecraft potential control ion current. Such estimates are of particular importance especially during periods when the plasma instruments are not in operation and also when electron density observations with higher time resolution than the ones available from particle detectors are necessary. We compare the average photoelectron emission of different spacecraft and discuss their differences. We examine several time intervals when we performed our density estimations in order to understand the strengths and weaknesses of our data set. We finally compare our derived density estimates with the plasma density observations provided by plasma detectors onboard MMS, whenever available, and discuss the overall results. The estimated electron densities should only be used as a proxy of the electron density, complimentary to the plasma moments derived by plasma detectors, especially when the latter are turned off or when higher time resolution observations are required. While the derived data set can often provide valuable information about the plasma environment, the actual values may often be very far from the actual plasma density values and should therefore be used with caution.

  • 18.
    Andrushchenko Zh.N., Pavlenko V.P.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics.
    Turbulent generation of large scale flows and nonlinear dynamics of flute modes2002In: Physics of Plasmas, Vol. 9, p. 4512-Article in journal (Refereed)
  • 19.
    Andrushchenko Zh.N., Pavlenko V.P., Schoepf K.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics.
    Theory of zonal flow generation by flute type turbulence2002In: Physica Scripta, Vol. 66, p. 326-Article in journal (Refereed)
  • 20.
    André, Mats
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Previously hidden low-energy ions: a better map of near-Earth space and the terrestrial mass balance2015In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. 90, no 12, article id 128005Article in journal (Refereed)
    Abstract [en]

    This is a review of the mass balance of planet Earth, intended also for scientists not usually working with space physics or geophysics. The discussion includes both outflow of ions and neutrals from the ionosphere and upper atmosphere, and the inflow of meteoroids and larger objects. The focus is on ions with energies less than tens of eV originating from the ionosphere. Positive low-energy ions are complicated to detect onboard sunlit spacecraft at higher altitudes, which often become positively charged to several tens of volts. We have invented a technique to observe low-energy ions based on the detection of the wake behind a charged spacecraft in a supersonic ion flow. We find that low-energy ions usually dominate the ion density and the outward flux in large volumes in the magnetosphere. The global outflow is of the order of 10(26) ions s(-1). This is a significant fraction of the total number outflow of particles from Earth, and changes plasma processes in near-Earth space. We compare order of magnitude estimates of the mass outflow and inflow for planet Earth and find that they are similar, at around 1 kg s(-1) (30 000 ton yr(-1)). We briefly discuss atmospheric and ionospheric outflow from other planets and the connection to evolution of extraterrestrial life.

  • 21.
    Argall, M. R.
    et al.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Paulson, K.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Alm, L.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Rager, A.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Dorelli, J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Shuster, J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Wang, S.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Torbert, R. B.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA; Southwest Res Inst, San Antonio, TX USA.
    Vaith, H.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Dors, I.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Chutter, M.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Farrugia, C.
    Univ New Hampshire, Ctr Space Sci, Durham, NH USA.
    Burch, J.
    Southwest Res Inst, San Antonio, TX USA.
    Pollock, C.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Giles, B.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Gershman, D.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Lavraud, B.
    Univ Toulouse, CNRS, Inst Rech Astrophys & Planetol, UPS, Toulouse, France..
    Russell, C. T.
    Univ Calif Los Angeles, Earth Planetary & Space Sci, Los Angeles, CA USA..
    Strangeway, R.
    Univ Calif Los Angeles, Earth Planetary & Space Sci, Los Angeles, CA USA..
    Magnes, W.
    Austrian Acad Sci, Space Res Inst, Graz, Austria.
    Lindqvist, P. -A
    KTH Royal Inst Technol, Stockholm, Sweden.
    Khotyaintsev, Yuri V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Ergun, R. E.
    Univ Colorado Boulder, Boulder, CO USA.
    Ahmadi, N.
    Univ Colorado Boulder, Boulder, CO USA.
    Electron Dynamics Within the Electron Diffusion Region of Asymmetric Reconnection2018In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, no 1, p. 146-162Article in journal (Refereed)
    Abstract [en]

    Abstract: We investigate the agyrotropic nature of electron distribution functions and their substructure to illuminate electron dynamics in a previously reported electron diffusion region (EDR) event. In particular, agyrotropy is examined as a function of energy to reveal detailed finite Larmor radius effects for the first time. It is shown that the previously reported approximate to 66eV agyrotropic "crescent" population that has been accelerated as a result of reconnection is evanescent in nature because it mixes with a denser, gyrotopic background. Meanwhile, accelerated agyrotropic populations at 250 and 500eV are more prominent because the background plasma at those energies is more tenuous. Agyrotropy at 250 and 500eV is also more persistent than at 66eV because of finite Larmor radius effects; agyrotropy is observed 2.5 ion inertial lengths from the EDR at 500eV, but only in close proximity to the EDR at 66eV. We also observe linearly polarized electrostatic waves leading up to and within the EDR. They have wave normal angles near 90 degrees, and their occurrence and intensity correlate with agyrotropy. Within the EDR, they modulate the flux of 500eV electrons travelling along the current layer. The net electric field intensifies the reconnection current, resulting in a flow of energy from the fields into the plasma.

    Plain Language Summary: The process of reconnection involves an explosive transfer of magnetic energy into particle energy. When energetic particles contact modern technology such as satellites, cell phones, or other electronic devices, they can cause random errors and failures. Exactly how particles are energized via reconnection, however, is still unknown. Fortunately, the Magnetospheric Multiscale mission is finally able to detect and analyze reconnection processes. One recent finding is that energized particles take on a crescent-shaped configuration in the vicinity of reconnection and that this crescent shape is related to the energy conversion process. In our paper, we explain why the crescent shape has not been observed until now and inspect particle motions to determine what impact it has on energy conversion. When reconnection heats the plasma, the crescent shape forms from the cool, tenuous particles. As plasmas from different regions mix, dense, nonheated plasma obscures the crescent shape in our observations. The highest-energy particle population created by reconnection, though, also contains features of the crescent shape that are more persistent but appear less dramatically in the data.

  • 22.
    Ashraf, Shakeel
    et al.
    Mid Sweden Univ, Dept Elect Design, Sundsvall, Sweden..
    Mattsson, Claes G.
    Mid Sweden Univ, Dept Elect Design, Sundsvall, Sweden..
    Fondell, Mattis
    Helmholtz Zentrum, Inst Methods & Instrumentat Synchrotron Radiat Re, Berlin, Germany..
    Lindblad, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Thungström, Göran
    Mid Sweden Univ, Dept Elect Design, Sundsvall, Sweden..
    Surface modification of SU-8 for metal/SU-8 adhesion using RF plasma treatment for application in thermopile detectors2015In: MATERIALS RESEARCH EXPRESS, ISSN 2053-1591, Vol. 2, no 8, article id 086501Article in journal (Refereed)
    Abstract [en]

    This article reports on plasma treatment of SU-8 epoxy in order to enhance adhesive strength for metals. Its samples were fabricated on standard silicon wafers and treated with (O-2 and Ar) RF plasma at a power of 25 W at a low pressure of (3 x 10(-3) Torr) for different time spans (10-70 s). The sample surfaces were characterized in terms of contact angle, surface (roughness and chemistry) and using a tape test. During the contact angle measurement, it was observed that the contact angle was reduced from 73 degrees to 5 degrees (almost wet) and 23 degrees for (O-2 and Ar) treated samples, respectively. The root mean square surface roughness was significantly increased by 21.5% and 37.2% for (O-2 and Ar) treatment, respectively. A pattern of metal squares was formed on the samples using photolithography for a tape test. An adhesive tape was applied to the samples and peeled off at 180 degrees The maximum adhesion results, more than 90%, were achieved for the O-2-treated samples, whereas the Ar-treated samples showed no change. The XPS study shows the formation of new species in the O-2-treated sample compared to the Ar-treated samples. The high adhesive results were due to the formation of hydrophilic groups and new O-2 species in the O-2-treated samples, which were absent in Ar-treated samples.

  • 23.
    Asp, Elina
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics.
    Drift-Type Waves in Rotating Tokamak Plasma2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The concept of energy production through the fusion of two light nuclei has been studied since the 1950’s. One of the major problems that fusion scientists have encountered is the confinement of the hot ionised gas, i.e. the plasma, in which the fusion process takes place. The most common way to contain the plasma is by using at magnetic field configuration, in which the plasma takes a doughnut-like shape. Experimental devices of this kind are referred to as tokamaks. For the fusion process to proceed at an adequate rate, the temperature of the plasma must exceed 100,000,000C. Such a high temperature forces the plasma out of thermodynamical equilibrium which plasma tries to regain by exciting a number of turbulent processes. After successfully quenching the lager scale magnetohydrodynamic turbulence that may instantly disrupt the plasma, a smaller scale turbulence revealed itself. As this smaller scale turbulence behaved contrary to the common theory at the time, it was referred to as anomalous. This kind of turbulence does not directly threaten existents of the plasma, but it allows for a leakage of heat and particles which inhibits the fusion reactions. It is thus essential to understand the origin of anomalous turbulence, the transport it generates and most importantly, how to reduce it. Today it is believed that anomalous transport is due to drift-type waves driven by temperature and density inhomogeneities and the theoretical treatment of these waves is the topic of this thesis.

    The first part of the thesis contains a rigorous analytical two-fluid treatment of drift waves driven solely by density inhomogeneities. Effects of the toroidal magnetic field configuration, the Landau resonance, a peaked diamagnetic frequency and a sheared rotation of the plasma have been taken into account. These effects either stabilise or destabilise the drift waves and to determine the net result on the drift waves requires careful analysis. To this end, dispersion relations have been obtained in various limits to determine when to expect the different effects to be dominant. The main result of this part is that with a large enough rotational shear, the drift waves will be quenched.

    In the second part we focus on temperature effects and thus treat reactive drift waves, specifically ion temperature gradient and trapped electron modes. In fusion plasmas the α-particles, created as a by-product of the fusion process, transfer the better part of their energy to the electrons and hence the electron temperature is expected to exceed the ion temperature. In most experiments until today, the ion temperature is greater than the electron temperature and this have been proven to improve the plasma confinement. To predict the performance of future fusion plasmas, where the fusion process is ongoing, a comprehensive study of hot-electron plasmas and external heating effects have been carried out. Especially the stiffness (heat flux vs. inverse temperature length scale) of the plasma has been examined. This work was performed by simulations done with the JETTO code utilising the Weiland model. The outcome of these simulations shows that the plasma response to strong heating is very stiff and that the plasma energy confinement time seems to vary little in the hot-electron mode.

    List of papers
    1. Ship-Wave Eigenmodes of Drift Type in Rotating Tokamak Plasmas
    Open this publication in new window or tab >>Ship-Wave Eigenmodes of Drift Type in Rotating Tokamak Plasmas
    2000 (English)In: Physica scripta. T, ISSN 0281-1847, Vol. 62, no 2-3, p. 169-176Article in journal (Refereed) Published
    Abstract [en]

    Ship waves of drift type in rotating plasma of axisymmetric, large aspect-ratio tokamaks with concentric, circular magnetic surfaces are investigated. Plasma rotation is driven by an electrostatic radial electric field and the waves under consideration may be excited by plasma flow past some static obstacle. The analysis performed is based on rigorously derived eigenmode equations coupled in poloidal mode numbers through toroidal effects. The existence of two qualitatively different types of ship wave eigenmodes is demonstrated. Namely (i) global modes that have a structure of quasimodes localised in both radial and poloidal directions and correspond to the bounded states in a potential well which are marginally stable and (ii) propagating modes that experience shear convective damping. The dispersion relations for both types of eigenmodes are obtained both in the weak and the strong coupling approximation.

    We find the analytical solutions of the dispersion relations and the regions of their existence which are defined, mainly, by the value and direction of the poloidal rotation velocity. An accumulation point for global ship eigenmodes is determined. For propagating ship waves the real and the imaginary parts of the poloidal wavenumber are found. It is shown that the imaginary part always corresponds to convective damping of these waves

    Keywords
    Ship waves of drift type in rotating plasma of axisymmetric, large aspect-ratio tokamaks with concentric, circular magnetic surfaces are investigated. Plasma rotation is driven by an electrostatic radial electric field and the waves under consideration ma
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-90344 (URN)10.1238/Physica.Regular.062a00169 (DOI)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2017-12-14Bibliographically approved
    2. Localising Effects of a Peaked Diamagnetic Frequency on Drift Modes in Rotating Tokamak Plasmas
    Open this publication in new window or tab >>Localising Effects of a Peaked Diamagnetic Frequency on Drift Modes in Rotating Tokamak Plasmas
    2002 (English)In: Physica scripta. T, ISSN 0281-1847, Vol. T98, no -, p. 151-154Article in journal (Refereed) Published
    Abstract [en]

    In this paper we investigate the effects of a diamagnetic frequency peaking and velocity shear on a two-dimensional drift mode structure. Previous study made by Horton et al. showed that a strong diamagnetic frequency peaking can trap the wave energy both radially and along the magnetic field lines. We show that the localising effect of the diamagnetic frequency peaking can be suppressed by a strong velocity shear in the edge plasma. The same phenomenon is present in the bulk plasma, but due to the velocity shear not being as pronounced there, the effect is nominal.

    National Category
    Fusion, Plasma and Space Physics
    Identifiers
    urn:nbn:se:uu:diva-90345 (URN)10.1238/Physica.Topical.098a00151 (DOI)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2017-12-14Bibliographically approved
    3. Stability of the Landau Resonance for Drift Modes in Rotating Tokamak Plasma
    Open this publication in new window or tab >>Stability of the Landau Resonance for Drift Modes in Rotating Tokamak Plasma
    2003 (English)In: Journal of Plasma Physics, ISSN 0022-3778, E-ISSN 1469-7807, Vol. 60, no 5, p. 371-Article in journal (Refereed) Published
    Abstract [en]

    The linear stability of drift waves in a poloidally rotating tokamak plasma is considered. The derived dispersion relation features a peaking of the diamagnetic frequency which gives the drift modes an irreducible two-dimensional character. We then show that inverse Landau damping can be suppressed and even stabilized, if the flow's shear is strong. Even though the instability, excited by the Landau resonance, is stronger at a high velocity shear for positive rotation velocities, effects due to the rotation of the plasma can reverse the sign and induce damping of the two-dimensional drift modes. This stabilizing mechanism works only for positive rotation velocities. For negative rotation velocities, we show that only modes with high poloidal mode numbers are unstable.

    National Category
    Fusion, Plasma and Space Physics
    Identifiers
    urn:nbn:se:uu:diva-90346 (URN)10.1017/S0022377803002253 (DOI)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2017-12-14Bibliographically approved
    4. JETTO Simulations of Te/Ti Effects on Plasma Confinement
    Open this publication in new window or tab >>JETTO Simulations of Te/Ti Effects on Plasma Confinement
    Show others...
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-90347 (URN)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2010-01-13Bibliographically approved
  • 24.
    Asp, Elina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics.
    Pavlenko, Vladimir P.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics.
    Revenchuk, Sergey M.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics.
    Localising Effects of a Peaked Diamagnetic Frequency on Drift Modes in Rotating Tokamak Plasmas2002In: Physica scripta. T, ISSN 0281-1847, Vol. T98, no -, p. 151-154Article in journal (Refereed)
    Abstract [en]

    In this paper we investigate the effects of a diamagnetic frequency peaking and velocity shear on a two-dimensional drift mode structure. Previous study made by Horton et al. showed that a strong diamagnetic frequency peaking can trap the wave energy both radially and along the magnetic field lines. We show that the localising effect of the diamagnetic frequency peaking can be suppressed by a strong velocity shear in the edge plasma. The same phenomenon is present in the bulk plasma, but due to the velocity shear not being as pronounced there, the effect is nominal.

  • 25.
    Asp, Elina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Astronomy and Space Physics.
    Pavlenko, Vladimir P.
    Revenchuk, Sergey M.
    Stability of the Landau Resonance for Drift Modes in Rotating Tokamak Plasma2003In: Journal of Plasma Physics, ISSN 0022-3778, E-ISSN 1469-7807, Vol. 60, no 5, p. 371-Article in journal (Refereed)
    Abstract [en]

    The linear stability of drift waves in a poloidally rotating tokamak plasma is considered. The derived dispersion relation features a peaking of the diamagnetic frequency which gives the drift modes an irreducible two-dimensional character. We then show that inverse Landau damping can be suppressed and even stabilized, if the flow's shear is strong. Even though the instability, excited by the Landau resonance, is stronger at a high velocity shear for positive rotation velocities, effects due to the rotation of the plasma can reverse the sign and induce damping of the two-dimensional drift modes. This stabilizing mechanism works only for positive rotation velocities. For negative rotation velocities, we show that only modes with high poloidal mode numbers are unstable.

  • 26.
    Backrud, Marie
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics.
    Cluster Observations and Theoretical Explanations of Broadband Waves in the Auroral Region2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Broadband extremely low-frequency wave emissions below the ion plasma frequency have been observed by a number of spacecraft and rockets on auroral field lines. The importance of these broadband emissions for transverse ion heating and electron acceleration in the auroral regions is now reasonably well established. However, the exact mechanism(s) for mediating this energy transfer and the wave mode(s) involved are not well known. In this thesis we focus on the identification of broadband waves by different methods.

    Two wave analysis methods, involving different approximations and assumptions, give consistent results concerning the wave mode identification. We find that much of the broadband emissions can be identified as a mixture of ion acoustic, electrostatic ion cyclotron and, ion Bernstein waves, which all can be described as different parts of the same dispersion surface in the linear theory of waves in homogeneous plasma.

    A new result is that ion acoustic waves occur on auroral magnetic field lines. These are found in relatively small regions interpreted as acceleration regions without cold (tens of eV) electrons.

    From interferometry we also determine the phase velocity and k vector for parallel and oblique ion acoustic waves. The retrieved characteristic phase velocity is of the order of the ion acoustic speed and larger than the thermal velocity of the protons. The typical wavelength is around the proton gyro radius and always larger than the Debye length which is consistent with ion acoustic waves.

    We have observed quasi-static parallel electric fields associated with the ion acoustic waves in regions with large-scale currents. Waves, in particular ion acoustic waves, can create an anomalous resistivity due to wave-particle interaction when electrons are retarded or trapped by the electric wave-field. To maintain the large-scale current, a parallel electric field is set up, which then can accelerate a second electron population to high velocities.

    List of papers
    1. Identification of Broadband Waves Above the Auroral Acceleration Region: CLUSTER Observations
    Open this publication in new window or tab >>Identification of Broadband Waves Above the Auroral Acceleration Region: CLUSTER Observations
    Show others...
    2004 In: Annales Geophysicae, ISSN 0992-7689, Vol. 22, no 12, p. 14-Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-93091 (URN)
    Available from: 2005-05-11 Created: 2005-05-11 Last updated: 2014-11-12Bibliographically approved
    2. Cluster observations and theoretical identification of broadband waves in the auroral region
    Open this publication in new window or tab >>Cluster observations and theoretical identification of broadband waves in the auroral region
    Show others...
    2005 (English)In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 23, no 12, p. 3739-3752Article in journal (Refereed) Published
    Abstract [en]

    Broadband waves are common on auroral field lines. We use two different methods to study the polarization of the waves at 10 to 180 Hz observed by the Cluster spacecraft at altitudes of about 4 Earth radii in the nightside auroral region. Observations of electric and magnetic wave fields, together with electron and ion data, are used as input to the methods. We find that much of the wave emissions are consistent with linear waves in homogeneous plasma. Observed waves with a large electric field perpendicular to the geomagnetic field are more common (electrostatic ion cyclotron waves), while ion acoustic waves with a large parallel electric field appear in smaller regions without suprathermal (tens of eV) plasma. The regions void of suprathermal plasma are interpreted as parallel potential drops of a few hundred volts.

    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-93092 (URN)10.5194/angeo-23-3739-2005 (DOI)000235008400015 ()
    Available from: 2005-05-11 Created: 2005-05-11 Last updated: 2017-12-14Bibliographically approved
    3. Interferometric Identification of Ion Acoustic Broadband Waves in the Auroral Region: CLUSTER Observations
    Open this publication in new window or tab >>Interferometric Identification of Ion Acoustic Broadband Waves in the Auroral Region: CLUSTER Observations
    Show others...
    2005 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 32, no 21Article in journal (Refereed) Published
    Abstract [en]

    [1] We determine the phase velocity and k vector for parallel and oblique broadband extremely low frequency, ELF, waves on nightside auroral magnetic field lines at altitudes around 4.6 RE. We use internal burst mode data from the EFW electric field and wave instrument onboard the Cluster spacecraft to retrieve phase differences between the four probes of the instrument. The retrieved characteristic phase velocity is of the order of the ion acoustic speed and larger than the thermal velocity of the protons. The typical wavelength obtained from interferometry is around the proton gyro radius and always larger than the Debye length. We find that in regions with essentially no suprathermal electrons above a few tens of eV the observed broadband waves above the proton gyro frequency are consistent with upgoing ion acoustic and oblique ion acoustic waves.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-93093 (URN)10.1029/2005GL022640 (DOI)
    Available from: 2005-05-11 Created: 2005-05-11 Last updated: 2017-12-14Bibliographically approved
    4. Direct Observations of Electric Fields and Particle Acceleration Caused by Anomalous Wave-Particle Resistivity in Space Plasmas
    Open this publication in new window or tab >>Direct Observations of Electric Fields and Particle Acceleration Caused by Anomalous Wave-Particle Resistivity in Space Plasmas
    Show others...
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-93094 (URN)
    Available from: 2005-05-11 Created: 2005-05-11 Last updated: 2010-01-13Bibliographically approved
  • 27.
    Bardos, Ladislav
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden..
    Baránková, Hana
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden..
    Bardos, A.
    BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden..
    Production of Hydrogen-Rich Synthesis Gas by Pulsed Atmospheric Plasma Submerged in Mixture of Water with Ethanol2017In: Plasma chemistry and plasma processing, ISSN 0272-4324, E-ISSN 1572-8986, Vol. 37, no 1, p. 115-123Article in journal (Refereed)
    Abstract [en]

    Hydrogen-rich synthesis gas was produced by pulsed dc plasma submerged into ethanol-water mixtures using an original system with a coaxial geometry. The ignition of the discharge is immediately followed by production of hydrogen and after a short time necessary for filling the outlet tubing a flame can be ignited. No auxiliary gas was used for the reforming process. The synthesis gas containing up to 60% of hydrogen was formed, at the outflow rate of 250 sccm at the average power as low as 10 W. The hydrogen production efficiency corresponds to 12 kWh/kg H-2.

  • 28.
    Baránková, Hana
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden.
    Bardos, Ladislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden.
    Bardos, Adela
    BB Plasma Design AB, Ullerakersvagen 64, SE-75643 Uppsala, Sweden.
    Non-Conventional Atmospheric Pressure Plasma Sources for Production of Hydrogen2018In: MRS ADVANCES, ISSN 2059-8521, Vol. 3, no 18, p. 921-929Article in journal (Refereed)
    Abstract [en]

    The atmospheric pressure plasma sources with a coaxial geometry were used for generation of the radio frequency, microwave and pulsed dc plasmas inside water and aqueous solutions. Pulsed dc plasma generated in ethanol-water mixtures leads to production of the hydrogen-rich synthesis gas with hydrogen content up to 65 % The effect of various plasma generation regimes on the performance of plasma, on the hydrogen production efficiency and on the hydrogen-rich synthesis gas production was examined. A role of the composition of the ethanol-water mixture was investigated.

  • 29.
    Behlke, Rico
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics.
    Dissipation at the Earth's Quasi-Parallel Bow Shock2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Earth's bow shock is a boundary where the solar wind becomes decelerated from supersonic to subsonic speed before being deflected around the Earth. This thesis presents measurements by the Cluster spacecraft upstream and at the Earth's quasi-parallel bow shock where the angle between the upstream magnetic field and the bow shock normal is less than 45 degrees. An intrinsic feature of quasi-parallel shocks is the ability of ions, that are reflected off the shock in a specular manner, to propagate far upstream and to interact with the incident solar wind. This leads to the generation of a variety of plasma waves, e.g., Ultra-Low Frequency (ULF) waves, which in their turn interact with the different ion populations. Some of the ULF waves are thought to steepen into so-called Short Large-Amplitude Magnetic Structures (SLAMS).

    This thesis studies the impact of SLAMS on the incident solar wind. SLAMS are thought to play an important role in terms of 1) returning shock-reflected ions back to the shock where they can eventually contribute to downstream thermalisation and 2) local pre-dissipation of the solar wind.

    The first electric field measurements of SLAMS showed a strong electric field rotation over SLAMS in association with the rotation of the magnetic field. This often leads to a local change from quasi-parallel to quasi-perpendicular conditions. In addition, short-scale electric field features were observed, e.g., spiky electric field structures associated with the leading edge of SLAMS and solitary electric field structures on Debye length scales, which are suggested to represent ion phase space holes.

    Using the abilitiy of the four Cluster satellites to obtain propagation vectors of SLAMS and the high-resolution electric field measurements, the electric potential over SLAMS was studied. These structures are associated with a significant potential on the order of a few hundred to thousand Volt. Comparing these findings with data from the ion spectrometer, it was found that the bulk flow is locally significantly decelerated and moderately deflected and heated. In addition, SLAMS reflect incident ions on both the leading and trailing edge. The flux of so-called gyrating ions show a clear maximum in association with SLAMS. This indicates that SLAMS indeed play an important role for pre-dissipation of the solar wind upstream of the shock.

    List of papers
    1. Multi-point electric field measurements of Short Large-Amplitude Magnetic Structures (SLAMS) at the Earth' quasi-parallel bow shock
    Open this publication in new window or tab >>Multi-point electric field measurements of Short Large-Amplitude Magnetic Structures (SLAMS) at the Earth' quasi-parallel bow shock
    Show others...
    2003 In: Geophysical Research Letters, ISSN 0094-8276, Vol. 30, no 4Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-93709 (URN)
    Available from: 2005-11-24 Created: 2005-11-24 Last updated: 2014-11-12Bibliographically approved
    2. Solitary structures associated with short large-amplitude magnetic structures (SLAMS) upstream of the Earth's quasi-parallel bow shock
    Open this publication in new window or tab >>Solitary structures associated with short large-amplitude magnetic structures (SLAMS) upstream of the Earth's quasi-parallel bow shock
    Show others...
    2004 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 31, no 16Article in journal (Refereed) Published
    Abstract [en]

    [1] For the first time, solitary waves (SWs) have been observed within short large-amplitude magnetic structures (SLAMS) upstream of the Earth's quasi-parallel bow shock. The SWs often occur as bipolar pulses in the electric field data and move parallel to the background magnetic field at velocities of v = 400–1200 km/s. They have peak-to-peak amplitudes in the parallel electric field of up to E = 65 mV/m and parallel scale sizes of L ∼ 10 λD. The bipolar solitary waves exhibit negative potential structures of ∣Φ∣ = 0.4–2.2 V, i.e., eΦ/kTe ∼ 0.1. None of the theories commonly used to describe SWs adequately address these negative potential structures moving at velocities above the ion thermal speed in a weakly magnetized plasma.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-93710 (URN)10.1029/2004GL019524 (DOI)
    Available from: 2005-11-24 Created: 2005-11-24 Last updated: 2017-12-14Bibliographically approved
    3. The electric potentialat the Earth's quasi-parallel bow shock: Initial Cluster results
    Open this publication in new window or tab >>The electric potentialat the Earth's quasi-parallel bow shock: Initial Cluster results
    Show others...
    2005 In: The physics of collisionless shocks: 4th Annual IGPP International Astrophysics Conference, 2005, p. 79-83Chapter in book (Other academic) Published
    Identifiers
    urn:nbn:se:uu:diva-93711 (URN)0-7354-0268-X (ISBN)
    Available from: 2005-11-24 Created: 2005-11-24Bibliographically approved
    4. Cluster observations of the electric potential at the Earth's quasi-parallel bow shock
    Open this publication in new window or tab >>Cluster observations of the electric potential at the Earth's quasi-parallel bow shock
    Show others...
    2005 In: Annales Geophysicae, ISSN 0992-7689Article in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-93712 (URN)
    Available from: 2005-11-24 Created: 2005-11-24Bibliographically approved
    5. Dissipation properties of SLAMS upstream of the Earth's quasi-parallel bow shock
    Open this publication in new window or tab >>Dissipation properties of SLAMS upstream of the Earth's quasi-parallel bow shock
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-93713 (URN)
    Available from: 2005-11-24 Created: 2005-11-24 Last updated: 2010-01-13Bibliographically approved
  • 30.
    Bellan, PM
    et al.
    Uppsala University, Department of Medical Pharmacology.
    Stasiewicz, K
    Fine-scale cavitation of ionospheric plasma caused by inertial Alfven wave ponderomotive force1998In: PHYSICAL REVIEW LETTERS, ISSN 0031-9007, Vol. 80, no 16, p. 3523-3526Article in journal (Refereed)
    Abstract [en]

    Deep, very narrow magnetic-field-aligned density depletions were observed by the Freja spacecraft during auroral oval crossings. These cavities have perpendicular width of the order of the Electron skin depth c/omega(pe) and are associated with low-freque

  • 31.
    Berglund, Martin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Persson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    A High-Performance Microplasma Source for Highly Sensitive and Robust Gas Analysis2014In: Proc. of Micronano System Workshop 2014, Uppsala, Sweden, May 15-16, 2014, 2014Conference paper (Other academic)
  • 32.
    Beth, A.
    et al.
    Imperial Coll London, Dept Phys, Prince Consort Rd, London SW7 2AZ, England..
    Altwegg, K.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Balsiger, H.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Berthelier, J. -J
    Calmonte, U.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Combi, M. R.
    Univ Michigan, Dept Atmospher Ocean & Space Sci, 2455 Hayward, Ann Arbor, MI 48109 USA..
    De Keyser, J.
    Royal Belgian Inst Space Aeron, BIRA, IASB, Ringlaan 3, B-1180 Brussels, Belgium..
    Dhooghe, F.
    Royal Belgian Inst Space Aeron, BIRA, IASB, Ringlaan 3, B-1180 Brussels, Belgium..
    Fiethe, B.
    TU Braunschweig, Inst Comp & Network Engn IDA, Hans Sommer Str 66, D-38106 Braunschweig, Germany..
    Fuselier, S. A.
    Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78228 USA.;Southwest Res Inst San Antonio, San Antonio, TX 78228 USA..
    Galand, M.
    Imperial Coll London, Dept Phys, Prince Consort Rd, London SW7 2AZ, England..
    Gasc, S.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Gombosi, T. I.
    Univ Michigan, Dept Atmospher Ocean & Space Sci, 2455 Hayward, Ann Arbor, MI 48109 USA..
    Hansen, K. C.
    Univ Michigan, Dept Atmospher Ocean & Space Sci, 2455 Hayward, Ann Arbor, MI 48109 USA..
    Hassig, M.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland.;Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78228 USA..
    Heritier, K. L.
    Imperial Coll London, Dept Phys, Prince Consort Rd, London SW7 2AZ, England..
    Kopp, E.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Le Roy, L.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Mandt, K. E.
    Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78228 USA.;Southwest Res Inst San Antonio, San Antonio, TX 78228 USA..
    Peroy, S.
    Imperial Coll London, Dept Phys, Prince Consort Rd, London SW7 2AZ, England..
    Rubin, M.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Semon, T.
    Univ Bern, Phys Inst, CH-3012 Bern, Switzerland..
    Tzou, C. -Y
    Vigren, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    First in situ detection of the cometary ammonium ion NH4+ (protonated ammonia NH3) in the coma of 67P/C-G near perihelion2016In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 462, p. S562-S572Article in journal (Refereed)
    Abstract [en]

    In this paper, we report the first in situ detection of the ammonium ion NH4+ at 67P/Churyumov-Gerasimenko (67P/C-G) in a cometary coma, using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Double Focusing Mass Spectrometer (DFMS). Unlike neutral and ion spectrometers onboard previous cometary missions, the ROSINA/DFMS spectrometer, when operated in ion mode, offers the capability to distinguish NH4+ from H2O+ in a cometary coma. We present here the ion data analysis of mass-to-charge ratios 18 and 19 at high spectral resolution and compare the results with an ionospheric model to put these results into context. The model confirms that the ammonium ion NH4+ is one of the most abundant ion species, as predicted, in the coma near perihelion.

  • 33.
    Binda, Federico
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Andersson Sundén, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Eriksson, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Hellesen, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Ericsson, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Absolute calibration of the JET neutron profile monitorIn: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623Article in journal (Refereed)
  • 34.
    Binda, Federico
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Characterization of a NE-213 liquid scintillator for neutron flux measurement at JET2011Other (Other academic)
    Abstract [en]

    The measurment of the total neutron rate from a nuclear fusion reactor is very important in order to calculate the power produced in a plasma. An improvement of a method currently in use at JET will involve the installation of an organic liquid scintillator NE-213 of 1 cm3 of volume combined with a digital acquisition card. 

    In this project a first stage of the characterization of the digitizer and of the detector has been performed.

  • 35.
    Binda, Federico
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    High Count Rate Neutron Detector Installation at JET2011Other (Other academic)
    Abstract [en]

    The measurement of fusion power is of paramount importance for the control of a fusion reactor's operation. The neutron yield from the reactor is strictly related to the energy production. One of the methods employed at JET to measure the yield involves the use of the MPRu spectrometer together with the neutron camera. However the MPRu has an intrinsically low efficiency (about 10-6), which results in a poor time resolution. An improvement involving the installation of a NE213 detectorfor high count rate has been proposed. The testing phase of the new instrumentation, conducted at Uppsala University, has shown that the acquisition system works properly and it is ready to be installed on site in view of the coming JET experimental campaign.

  • 36.
    Binda, Federico
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Liquid scintillators as neutron diagnostic tools for fusion plasmas: System characterization and data analysis2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The neutrons produced in fusion devices carry information about various properties of the ions that are reacting in the machine. Measurements of the neutron flux and energy distribution can therefore be used to study the behaviour of the plasma ions under different experimental conditions.

    Several neutron detection techniques are available, each having advantages and disadvantages compared to the others. In this thesis we study neutron measurements performed with NE213 liquid scintillators. One advantage of NE213s compared to other neutron detection techniques is that they are simple to use, small and cheap. On the other hand, their response to neutrons makes the extraction of information about the neutron energy less precise.

    In the thesis we present the development of methods for the characterization and the data analysis of NE213 detectors. The work was performed using two instruments installed at the Joint European Torus (JET) tokamak in the UK: the “Afterburner” detector, which is an NE213 installed on a tangential line of sight, and the neutron camera, which is a system composed of 19 NE213 detectors installed on different lines of sight (10 horizontal and 9 vertical).The analysis of data from the Afterburner detector was focused on resolving different features of the neutron energy spectra which are related to different properties of the ion velocity distribution.

    The analysis of data from the neutron camera was directed towards the investigation of the spatial distribution of ions in the plasma. However, the individual characterization of the camera detectors allowed the inclusion of information about the energy distribution of the ions in the analysis.

    The outcomes of the studies performed indicate that the methods developed give reliable results and can therefore be applied to extract information about the plasma ions. In particular, the possibility of performing neutron emission spectroscopy analysis in each line of sight of a neutron camera is of great value for future studies.

    List of papers
    1. Generation of the neutron response function of an NE213 scintillator for fusion applications
    Open this publication in new window or tab >>Generation of the neutron response function of an NE213 scintillator for fusion applications
    Show others...
    2017 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 866, p. 222-229Article in journal (Refereed) Published
    Abstract [en]

    In this work we present a method to evaluate the neutron response function of an NE213 liquid scintillator. This method is particularly useful when the proton light yield function of the detector has not been measured, since it is based on a proton light yield function taken from literature, MCNPX simulations, measurements of gammarays from a calibration source and measurements of neutrons from fusion experiments with ohmic plasmas. The inclusion of the latter improves the description of the proton light yield function in the energy range of interest (around 2.46 MeV). We apply this method to an NE213 detector installed at JET, inside the radiation shielding of the magnetic proton recoil (MPRu) spectrometer, and present the results from the calibration along with some examples of application of the response function to perform neutron emission spectroscopy (NES) of fusion plasmas. We also investigate how the choice of the proton light yield function affects the NES analysis, finding that the result does not change significantly. This points to the fact that the method for the evaluation of the neutron response function is robust and gives reliable results.

    Keywords
    NE213 scintillator, Neutron spectroscopy, Response function, Proton light yield
    National Category
    Atom and Molecular Physics and Optics
    Identifiers
    urn:nbn:se:uu:diva-330537 (URN)10.1016/j.nima.2017.04.023 (DOI)000407863700029 ()
    Available from: 2017-10-04 Created: 2017-10-04 Last updated: 2018-04-23Bibliographically approved
    2. Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET
    Open this publication in new window or tab >>Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET
    Show others...
    2014 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 85, no 11, p. 11E123-Article in journal (Refereed) Published
    Abstract [en]

    In this paper, we present the results obtained from the data analysis of neutron spectra measured with a NE213 liquid scintillator at JET. We calculated the neutron response matrix of the instrument combining MCNPX simulations, a generic proton light output function measured with another detector and the fit of data from ohmic pulses. For the analysis, we selected a set of pulses with neutral beam injection heating (NBI) only and we applied a forward fitting procedure of modeled spectral components to extract the fraction of thermal neutron emission. The results showed the same trend of the ones obtained with the dedicated spectrometer TOFOR, even though the values from the NE213 analysis were systematically higher. This discrepancy is probably due to the different lines of sight of the two spectrometers (tangential for the NE213, vertical for TOFOR). The uncertainties on the thermal fraction estimates were from 4 to 7 times higher than the ones from the TOFOR analysis.

    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-240136 (URN)10.1063/1.4895565 (DOI)000345646000143 ()25430302 (PubMedID)
    Available from: 2015-01-07 Created: 2015-01-05 Last updated: 2018-04-23
    3. Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET
    Open this publication in new window or tab >>Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET
    Show others...
    2015 (English)In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 55, no 12, article id 123026Article in journal (Refereed) Published
    Abstract [en]

    Observations made in a JET experiment aimed at accelerating deuterons to the MeV range by third harmonic radio-frequency (RF) heating coupled into a deuterium beam are reported. Measurements are based on a set of advanced neutron and gamma-ray spectrometers that, for the first time, observe the plasma simultaneously along vertical and oblique lines of sight. Parameters of the fast ion energy distribution, such as the high energy cut-off of the deuteron distribution function and the RF coupling constant, are determined from data within a uniform analysis framework for neutron and gamma-ray spectroscopy based on a one-dimensional model and by a consistency check among the individual measurement techniques. A systematic difference is seen between the two lines of sight and is interpreted to originate from the sensitivity of the oblique detectors to the pitch-angle structure of the distribution around the resonance, which is not correctly portrayed within the adopted one dimensional model. A framework to calculate neutron and gamma-ray emission from a spatially resolved, two-dimensional deuteron distribution specified by energy/pitch is thus developed and used for a first comparison with predictions from ab initio models of RF heating at multiple harmonics.

    The results presented in this paper are of relevance for the development of advanced diagnostic techniques for MeV range ions in high performance fusion plasmas, with applications to the experimental validation of RF heating codes and, more generally, to studies of the energy distribution of ions in the MeV range in high performance deuterium and deuterium-tritium plasmas.

    Keywords
    fusion, tokamak, fast ions, neutron spectrometry, gamma-ray spectroscopy
    National Category
    Fusion, Plasma and Space Physics
    Research subject
    Physics with specialization in Applied Nuclear Physics
    Identifiers
    urn:nbn:se:uu:diva-247990 (URN)10.1088/0029-5515/55/12/123026 (DOI)000366534500028 ()
    Available from: 2015-03-25 Created: 2015-03-25 Last updated: 2018-04-23Bibliographically approved
    4. Absolute calibration of the JET neutron profile monitor
    Open this publication in new window or tab >>Absolute calibration of the JET neutron profile monitor
    Show others...
    (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623Article in journal (Refereed) Submitted
    National Category
    Fusion, Plasma and Space Physics
    Identifiers
    urn:nbn:se:uu:diva-345980 (URN)
    Available from: 2018-03-13 Created: 2018-03-13 Last updated: 2018-03-13
    5. Calculation of the profile-dependent neutron backscatter matrix for the JET neutron camera system
    Open this publication in new window or tab >>Calculation of the profile-dependent neutron backscatter matrix for the JET neutron camera system
    2017 (English)In: Fusion engineering and design, ISSN 0920-3796, E-ISSN 1873-7196, Vol. 123, p. 865-868Article in journal (Refereed) Published
    Abstract [en]

    We investigated the dependence of the backscatter component of the neutron spectrum on the emissivity profile. We did so for the JET neutron camera system, by calculating a profile-dependent backscatter matrix for each of the 19 camera channels using a MCNP model of the JET tokamak. We found that, when using a low minimum energy for the summation of the counts in the neutron pulse height spectrum, the backscatter contribution can depend significantly on the emissivity profile. The maximum variation in the backscatter level was 24% (8.0% when compared to the total emission). This effect needs to be considered when a correction for the backscatter contribution is applied to the measured profile.

    Place, publisher, year, edition, pages
    ELSEVIER SCIENCE SA, 2017
    Keywords
    Neutron, Profile monitor, Backscatter, mcnp
    National Category
    Subatomic Physics
    Identifiers
    urn:nbn:se:uu:diva-341822 (URN)10.1016/j.fusengdes.2017.03.124 (DOI)000418992000181 ()
    Conference
    29th Symposium on Fusion Technology (SOFT), SEP 05-09, 2016, Prague, CZECH REPUBLIC
    Available from: 2018-02-15 Created: 2018-02-15 Last updated: 2018-03-13Bibliographically approved
    6. Study of the energy-dependent fast ion redistribution during sawtooth oscillations with the neutron camera at JET
    Open this publication in new window or tab >>Study of the energy-dependent fast ion redistribution during sawtooth oscillations with the neutron camera at JET
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Fusion, Plasma and Space Physics
    Identifiers
    urn:nbn:se:uu:diva-345982 (URN)
    Available from: 2018-03-13 Created: 2018-03-13 Last updated: 2018-04-23
  • 37.
    Binda, Federico
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Eriksson, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Ericsson, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Hellesen, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Cecconello, Marco
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Nocente, Massimo
    Cazzaniga, Carlo
    Andersson Sundén, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Analysis of the fast ion tails observed in the NE213pulse height specta measured during third harmonicradio-frequency heating experiments at JETManuscript (preprint) (Other academic)
    Abstract [en]

    In this paper we investigate the possibility of using a NE213 liquid scintillator as aneutron spectrometer to diagnose the fast ion tails produced in experiments with 3rd harmonicradio-frequency heating.We discuss mainly the instrumental effects that need to be considered and corrected for in orderto obtain a good agreement between measured data and models: gain drift, pile-up, impact of theassumption of a standard proton light yield function. We also address problems related to thepresence of triton burn-up events in the spectrum.The expected ion distribution is obtained from a simple 1D Fokker-Planck model. The parametersof the model are estimated using the data collected by the TOFOR neutron spectrometer.The agreement between the data and the model is good and it is possible to make a clear distinctionbetween discharges that had different electron densities and thus different cut-off energies. Wecan conclude that NE213 scintillators can provide useful spectroscopic information for this kind ofexperiments.

  • 38.
    Binda, Federico
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Eriksson, Jacob
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Hellesen, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Ericsson, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Andersson Sundén, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Conroy, Sean
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Fabien, Jaulmes
    Study of the energy-dependent fast ion redistribution during sawtooth oscillations with the neutron camera at JETManuscript (preprint) (Other academic)
  • 39.
    Bladh, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Höfner, Susanne
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Aringer, Bernhard
    Univ Vienna, Dept Astrophys, A-1010 Vienna, Austria..
    Eriksson, Kjell
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Exploring Mass-Loss in M-type AGB Stars2015In: WHY GALAXIES CARE ABOUT AGB STARS III: A CLOSER LOOK IN SPACE AND TIME, ASTRONOMICAL SOC PACIFIC , 2015, Vol. 497, p. 345-350Conference paper (Refereed)
    Abstract [en]

    Stellar winds observed in asymptotic giant branch (AGB) stars are usually attributed to a combination of stellar pulsations and radiation pressure on dust. Strong candidates for wind-driving dust species in M-type AGB stars are magnesium silicates (Mg2SiO4 and MgSiO3). Such grains can form close to the stellar surface; they consist of abundant materials and, if they grow to sizes comparable to the wavelength of the stellar flux maximum, they experience strong acceleration by photon scattering. Here we present results from an extensive set of time-dependent wind models for M-type AGB stars with a detailed description for the growth of Mg2SiO4 grains. We show that these models reproduce observed mass-loss rates and wind velocities, as well as visual and near-IR photometry. However, the current models do not show the characteristic silicate features at 10 and 18 mu m, due to a rapidly falling temperature of Mg2SiO4 grains in the wind. Including a small amount of Fe in the grains further out in the circumstellar envelope will increase the grain temperature and result in pronounced silicate features, without significantly affecting the photometry in the visual and near-IR.

  • 40.
    Blanco-Cano, Xochitl
    et al.
    Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City, DF, Mexico..
    Battarbee, Markus
    Univ Helsinki, Dept Phys, Helsinki, Finland..
    Turc, Lucile
    Univ Helsinki, Dept Phys, Helsinki, Finland..
    Dimmock, Andrew P.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division. Aalto Univ, Sch Elect Engn, Dept Elect & Nanoengn, Espoo, Finland..
    Kilpua, Emilia K. J.
    Univ Helsinki, Dept Phys, Helsinki, Finland..
    Hoilijoki, Sanni
    Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
    Ganse, Urs
    Univ Helsinki, Dept Phys, Helsinki, Finland..
    Sibeck, David G.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Cassak, Paul A.
    West Virginia Univ, Dept Phys & Astron, Morgantown, WV USA..
    Fear, Robert C.
    Univ Southampton, Dept Phys & Astron, Southampton, Hants, England..
    Jarvinen, Riku
    Aalto Univ, Sch Elect Engn, Dept Elect & Nanoengn, Espoo, Finland.;Finnish Meteorol Inst, Helsinki, Finland..
    Juusola, Liisa
    Univ Helsinki, Dept Phys, Helsinki, Finland.;Finnish Meteorol Inst, Helsinki, Finland..
    Pfau-Kempf, Yann
    Univ Helsinki, Dept Phys, Helsinki, Finland..
    Vainio, Rami
    Univ Turku, Dept Phys & Astron, Turku, Finland..
    Palmroth, Minna
    Univ Helsinki, Dept Phys, Helsinki, Finland.;Finnish Meteorol Inst, Helsinki, Finland..
    Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation2018In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 36, no 4, p. 1081-1097Article in journal (Refereed)
    Abstract [en]

    In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magnetospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report on SHFAs surviving the shock crossing into the down-stream region and show that the interaction of SHFAs with the bow shock can lead to the formation of a magnetosheath cavity, previously identified in observations and simulations. We report on the first identification of long-term local weakening and erosion of the bow shock, associated with a region of increased foreshock SHFA and caviton formation, and repeated shock crossings by them. We show that SHFAs are linked to an increase in suprathermal particle pitch-angle spreads. The realistic length scales in our simulation allow us to present a statistical study of global caviton and SHFA size distributions, and their comparable size distributions support the theory that SHFAs are formed from cavitons. Virtual spacecraft observations are shown to be in good agreement with observational studies.

  • 41.
    Borlenghi, Simone
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Gauge invariance and geometric phase in nonequilibrium thermodynamics2016In: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics, ISSN 1539-3755, E-ISSN 1550-2376, Vol. 93, no 1, article id 012133Article in journal (Refereed)
    Abstract [en]

    We show the link between U(1) lattice gauge theories and the off-equilibrium thermodynamics of a large class of nonlinear oscillators networks. The coupling between the oscillators plays the role of a gauge field, or connection, on the network. The thermodynamical forces that drive energy flows are expressed in terms of the curvature of the connection, analogous to a geometric phase. The model, which holds both close and far from equilibrium, predicts the existence of persistent energy and particle currents circulating in closed loops through the network. The predictions are confirmed by numerical simulations. Possible extension of the theory and experimental applications to nanoscale devices are briefly discussed.

  • 42.
    Borälv, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Substorm Features in the High-Latitude Ionosphere and Magnetosphere: Multi-Instrument Observations2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The space around Earth, confined in the terrestrial magnetosphere, is to some extent shielded from the Sun's solar wind plasma and magnetic field. During certain conditions, however, strong interaction can occur between the solar wind and the magnetosphere, resulting in magnetospheric activity of several forms, among which substorms and storms are the most prominent. A general framework for how these processes work have been outlayed through the history of research, however, there still remain questions to be answered. The most striking example regards the onset of substorms, where both the onset cause and location in the magnetosphere/ionosphere are still debated. These are clearly not easily solved problems, since a substorm is a global process, ideally requiring simultaneous measurements in the magnetotail and ionosphere. Investigated in this work are temporal and spatial scales for substorm and convection processes in the Earth's magnetosphere and ionosphere. This is performed by combining observations from a number of both ground-based and spacecraft-borne instruments. The observations indicate that the magnetotail's cross-section is involved to a larger spatial extent than previously considered in the substorm process. Furthermore, convection changes result in topological changes of the magnetosphere on a fast time scale. The results show that the magnetosphere is, on a global magnetospheric scale, highly dynamic during convection changes and ensuing substorms.

    List of papers
    1. The dawn and dusk electrojet response to substorm onset
    Open this publication in new window or tab >>The dawn and dusk electrojet response to substorm onset
    Show others...
    2000 (English)In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 18, no 9, p. 1097-1107Article in journal (Refereed) Published
    Abstract [en]

    We have investigated the time delay between substorm onset and related reactions in the dawn and dusk ionospheric electrojets, clearly separated from the nightside located substorm current wedge by several hours in MLT. We looked for substorm onsets occurring over Greenland, where the onset was identified by a LANL satellite and DMI magnetometers located on Greenland. With this setup the MARIA magnetometer network was located at dusk, monitoring the eastward electrojet, and the IMAGE chain at dawn, for the westward jet. In the first few minutes following substorm onset, sudden enhancements of the electrojets were identified by looking for rapid changes in magnetograms. These results show that the speed of information transfer between the region of onset and the dawn and dusk ionosphere is very high. A number of events where the reaction seemed to preceed the onset were explained by either unfavorable instrument locations, preventing proper onset timing, or by the inner magnetosphere's reaction to the Earthward fast flows from the near-Earth neutral line model. Case studies with ionospheric coherent (SuperDARN) and incoherent (EISCAT) radars have been performed to see whether a convection-induced electric field or enhanced conductivity is the main agent for the reactions in the electrojets. The results indicate an imposed electric field enhancement.

    Keywords
    Polar ionosphere, Electric field, Magnetospheric substorm, Delay time, Auroral electrojet, Radar observation, Magnetometry, Satellite observation, Greenland, North America, America
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-90580 (URN)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2017-12-14Bibliographically approved
    2. Timing of substorm onset signatures on the ground and at geostationary orbit
    Open this publication in new window or tab >>Timing of substorm onset signatures on the ground and at geostationary orbit
    2002 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 29, no 12, p. 33(1)-33(4)Article in journal (Refereed) Published
    Abstract [en]

    In order to study the relative timing of substorm onset signatures on the ground and at geostationary orbit we have used data of simultaneous dispersionless electron and proton injections from the LANL satellite 1991-80, located slightly westward of Scandinavia. Out of 9 years of data we have identified a number of events during which such injections occurred close to local magnetic midnight. By careful inspection of ground-based magnetograms from the Scandinavian magnetometer network, IMAGE, we then identified the location and time of the formation of a substorm current wedge (SCW) during these events. 40 clear cases of geostationary injections, which were clearly associated with the formation of SCWs, were found. A statistical study of these events reveals that there is a clear time delay of the order of several minutes in the occurrence of the substorm injection with respect to the first indication of the SCW measured on the ground.

    Keywords
    Europe, Scandinavia, Statistical analysis, Ion injection, Magnetosphere, Magnetospheric substorm, Delay time, Magnetogram, Proton, Electron injection, Timing
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-90581 (URN)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2017-12-14Bibliographically approved
    3. The global ionospheric response to a southward IMF turning
    Open this publication in new window or tab >>The global ionospheric response to a southward IMF turning
    Show others...
    In: Annales Geophysicae, ISSN 0992-7689Article in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-90582 (URN)
    Available from: 2003-05-15 Created: 2003-05-15Bibliographically approved
    4. Correlation between ground-based observations of substorm signatures and magnetotail dynamics
    Open this publication in new window or tab >>Correlation between ground-based observations of substorm signatures and magnetotail dynamics
    Show others...
    2005 (English)In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 23, p. 997-1011Article in journal (Refereed) Published
    Abstract [en]

    We present a substorm event study combining Cluster and ground-based instrumentation. For this event ground-based magnetograms show a substorm onset and two separate substorm intensifications over Scandinavia, at the time located in the pre-midnight sector. During the substorm Cluster is located in the southern plasma sheet at a downtail distance of 18.5 Re. For all the substorm signatures seen on ground, corresponding plasma sheet drop-outs and re-entries of all or individual spacecraft of the Cluster constellation are observed. In general, plasma sheet drop-outs are assumed to be due to plasma sheet thinning/thickening and/or to magnetotail flapping. However, in the literature there has been some disagreement on both spatial and temporal characteristics of plasma sheet thinning and thickening during substorms. We therefore investigate the causes for the plasma sheet drop-outs for this event, which at first glance appears to show plasma sheet thinning at substorm onset, contradictory to the present standpoint in the literature.

    Keywords
    Magnetospheric configuration and dynamics, Magnetotail, Plasma sheet, Storms and substorms
    National Category
    Physical Sciences
    Identifiers
    urn:nbn:se:uu:diva-90583 (URN)
    Available from: 2003-05-15 Created: 2003-05-15 Last updated: 2017-12-14Bibliographically approved
    5. Storm-time intense proton aurora and its relation to plasma sheet density
    Open this publication in new window or tab >>Storm-time intense proton aurora and its relation to plasma sheet density
    In: Annales Geophysicae, ISSN 0092-7689Article in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-90584 (URN)
    Available from: 2003-05-15 Created: 2003-05-15Bibliographically approved
  • 43.
    Boström, Rolf
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Astronomy and Space Physics. Department of Physics and Astronomy, Space and Plasma Physics.
    Kinetic and space charge control of current flow and voltage drops along magnetic flux tubes: 2. Space charge effects2004In: J. Geophys. Res., Vol. 109, p. A01208-Article in journal (Refereed)
  • 44.
    Broiles, Thomas W.
    et al.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Burch, J. L.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Chae, K.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Clark, G.
    Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA..
    Cravens, T. E.
    Univ Kansas, Dept Phys & Astron, 1450 Jayhawk Blvd, Lawrence, KS 66045 USA..
    Eriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Fuselier, S. A.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA.;Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78249 USA..
    Frahm, R. A.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Gasc, S.
    Univ Bern, Phys Inst, Sidlerstr 5, CH-3012 Bern, Switzerland..
    Goldstein, R.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Henri, P.
    CNRS, LPC2E, F-45071 Orleans, France..
    Koenders, C.
    Tech Univ Carolo Wilhelmina Braunschweig, Inst Geophys & Extraterr Phys, Mendelssohnstr 3, D-38106 Braunschweig, Germany..
    Livadiotis, G.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Mandt, K. E.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA.;Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78249 USA..
    Mokashi, P.
    Southwest Res Inst, Div Space Sci & Engn, 6220 Culebra Rd, San Antonio, TX 78238 USA..
    Nemeth, Z.
    Wigner Res Ctr Phys, H-1121 Budapest, Hungary..
    Odelstad, Elias
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Space Plasma Physics. Univ Kansas, Dept Phys & Astron, 1450 Jayhawk Blvd, Lawrence, KS 66045 USA..
    Rubin, M.
    Univ Bern, Phys Inst, Sidlerstr 5, CH-3012 Bern, Switzerland..
    Samara, M.
    Goddard Space Flight Ctr, Heliophys Div, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA..
    Statistical analysis of suprathermal electron drivers at 67P/Churyumov-Gerasimenko2016In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 462, p. S312-S322Article in journal (Refereed)
    Abstract [en]

    We use observations from the Ion and Electron Sensor (IES) on board the Rosetta spacecraft to study the relationship between the cometary suprathermal electrons and the drivers that affect their density and temperature. We fit the IES electron observations with the summation of two kappa distributions, which we characterize as a dense and warm population (similar to 10 cm(-3) and similar to 16 eV) and a rarefied and hot population (similar to 0.01 cm(-3) and similar to 43 eV). The parameters of our fitting technique determine the populations' density, temperature, and invariant kappa index. We focus our analysis on the warm population to determine its origin by comparing the density and temperature with the neutral density and magnetic field strength. We find that the warm electron population is actually two separate sub-populations: electron distributions with temperatures above 8.6 eV and electron distributions with temperatures below 8.6 eV. The two sub-populations have different relationships between their density and temperature. Moreover, the two sub-populations are affected by different drivers. The hotter sub-population temperature is strongly correlated with neutral density, while the cooler sub-population is unaffected by neutral density and is only weakly correlated with magnetic field strength. We suggest that the population with temperatures above 8.6 eV is being heated by lower hybrid waves driven by counterstreaming solar wind protons and newly formed, cometary ions created in localized, dense neutral streams. To the best of our knowledge, this represents the first observations of cometary electrons heated through wave-particle interactions.

  • 45. Brunetti, D
    et al.
    Cooper, W A
    Graves, J P
    Halpern, F
    Wahlberg, C
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Space Plasma Physics.
    Lutjens, H
    Luciani, J F
    MHD properties in the core of ITER-like hybrid scenarios2012In:  , 2012Conference paper (Refereed)
  • 46.
    Brunetti, D.
    et al.
    CNR, IFP, Via R Cozzi 53, I-20125 Milan, Italy..
    Graves, J. P.
    SPC, CH-1015 Lausanne, Switzerland..
    Lazzaro, E.
    CNR, IFP, Via R Cozzi 53, I-20125 Milan, Italy..
    Mariani, A.
    CNR, IFP, Via R Cozzi 53, I-20125 Milan, Italy.;SPC, CH-1015 Lausanne, Switzerland..
    Nowak, S.
    CNR, IFP, Via R Cozzi 53, I-20125 Milan, Italy..
    Cooper, W. A.
    SPC, CH-1015 Lausanne, Switzerland..
    Wahlberg, Christer
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Space Plasma Physics.
    Analytic stability criteria for edge MHD oscillations in high performance ELM free tokamak regimes2018In: Nuclear Fusion, ISSN 0029-5515, E-ISSN 1741-4326, Vol. 58, no 1, article id 014002Article in journal (Refereed)
    Abstract [en]

    A new dispersion relation, and associated stability criteria, is derived for low-n external kink and infernal modes, and is applied to modelling the stability properties of quiescent H-mode like regimes. The analysis, performed in toroidal geometry with large edge pressure gradients associated with a local flattening of the safety factor, includes a pedestal, sheared toroidal rotation and a vacuum region separating the plasma from an ideal metallic wall. The external kink-infernal modes found here exhibit similarities with experimentally observed edge harmonic oscillations.

  • 47.
    Brunetti, Daniele
    et al.
    CNR, IFP, Milan, Italy.
    Graves, J. P.
    SPC, Lausanne, Switzerland.
    Lazzaro, E.
    CNR, IFP, Milan, Italy.
    Mariani, A.
    CNR, IFP, Milan, Italy.
    Nowak, S.
    CNR, IFP, Milan, Italy.
    Cooper, W. A.
    SPC, Lausanne, Switzerland.
    Wahlberg, Christer
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Analytic study on low-n external ideal infernal modes in tokamaks with large edge pressure gradients2018In: Journal of Plasma Physics, ISSN 0022-3778, E-ISSN 1469-7807, Vol. 84, no 2, article id 745840201Article in journal (Refereed)
    Abstract [en]

    The problem of pressure driven infernal type perturbations near the plasma edge is addressed analytically for a circular limited tokamak configuration which presents an edge flattened safety factor. The plasma is separated from a metallic wall, either ideally conducting or resistive, by a vacuum region. The dispersion relation for such types of instabilities is derived and discussed for two classes of equilibrium profiles for pressure and mass density.

  • 48.
    Brunetti, Daniele
    et al.
    EPFL, Lausanne, Schweiz.
    Wahlberg, C
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Space Plasma Physics.
    Resistive instabilities in low magnetic shear tokamak configuration2013Conference paper (Refereed)
  • 49. Bunce, E. J.
    et al.
    Grodent, D. C.
    Jinks, S. L.
    Andrews, David J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Badman, S. V.
    Coates, A. J.
    Cowley, S. W. H.
    Dougherty, M. K.
    Kurth, W. S.
    Mitchell, D. G.
    Provan, G.
    Cassini nightside observations of the oscillatory motion of Saturn's northern auroral oval2014In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, Vol. 119, no 5, p. 3528-3543Article in journal (Refereed)
    Abstract [en]

    In recent years we have benefitted greatly from the first in-orbit multi-wavelength images of Saturn's polar atmosphere from the Cassini spacecraft. Specifically, images obtained from the Cassini UltraViolet Imaging Spectrograph (UVIS) provide an excellent view of the planet's auroral emissions, which in turn give an account of the large-scale magnetosphere-ionosphere coupling and dynamics within the system. However, obtaining near-simultaneous views of the auroral regions with in situ measurements of magnetic field and plasma populations at high latitudes is more difficult to routinely achieve. Here we present an unusual case, during Revolution 99 in January 2009, where UVIS observes the entire northern UV auroral oval during a 2h interval while Cassini traverses the magnetic flux tubes connecting to the auroral regions near 21 LT, sampling the related magnetic field, particle, and radio and plasma wave signatures. The motion of the auroral oval evident from the UVIS images requires a careful interpretation of the associated latitudinally oscillating magnetic field and auroral field-aligned current signatures, whereas previous interpretations have assumed a static current system. Concurrent observations of the auroral hiss (typically generated in regions of downward directed field-aligned current) support this revised interpretation of an oscillating current system. The nature of the motion of the auroral oval evident in the UVIS image sequence, and the simultaneous measured motion of the field-aligned currents (and related plasma boundary) in this interval, is shown to be related to the northern hemisphere magnetosphere oscillation phase. This is in agreement with previous observations of the auroral oval oscillatory motion.

  • 50.
    Burch, J. L.
    et al.
    Southwest Res Inst, San Antonio, TX, USA.
    Webster, J. M.
    Rice Univ, Dept Phys & Astron, Houston, TX USA.
    Genestreti, K. J.
    Austrian Acad Sci, Space Res Inst, Graz, Austria.
    Torbert, R. B.
    Southwest Res Inst, San Antonio, TX, USA; Univ New Hampshire, Dept Phys, Durham, NH, USA.
    Giles, B. L.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Fuselier, S. A.
    Southwest Res Inst, San Antonio, TX, USA.
    Dorelli, J. C.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
    Rager, A. C.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA; Catholic Univ Amer, Dept Phys, Washington DC, USA..
    Phan, T. D.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA, USA.
    Allen, R. C.
    Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA.
    Chen, L. -J
    Univ Maryland, Dept Astron, College Pk, MD, USA.
    Wang, S.
    Univ Maryland, Dept Astron, College Pk, MD, USA.
    Le Contel, O.
    Univ Paris Sud, UPMC Univ Paris 06, Lab Phys Plasmas, CNRS, Ecole Polytech,Observ Paris, Paris, France.
    Russell, C. T.
    Univ Calif Los Angeles, Earth & Planetary Sci, Los Angeles, CA, USA.
    Strangeway, R. J.
    Univ Calif Los Angeles, Earth & Planetary Sci, Los Angeles, CA, USA.
    Ergun, R. E.
    Univ Colorado, LASP, Boulder, CO, USA.
    Jaynes, A. N.
    Univ Iowa, Dept Phys & Astron, Iowa City, IA, USA.
    Lindqvist, P. -A
    Royal Inst Technol, Stockholm, Sweden.
    Graham, Daniel B.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Swedish Institute of Space Physics, Uppsala Division.
    Wilder, F. D.
    Univ Colorado, LASP, Boulder, CO, USA.
    Hwang, K. -J
    Southwest Res Inst, San Antonio, TX, USA.
    Goldstein, J.
    Southwest Res Inst, San Antonio, TX, USA.
    Wave Phenomena and Beam-Plasma Interactions at the Magnetopause Reconnection Region2018In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, no 2, p. 1118-1133Article in journal (Refereed)
    Abstract [en]

    This paper reports on Magnetospheric Multiscale observations of whistler mode chorus and higher-frequency electrostatic waves near and within a reconnection diffusion region on 23 November 2016. The diffusion region is bounded by crescent-shaped electron distributions and associated dissipation just upstream of the X-line and by magnetic field-aligned currents and electric fields leading to dissipation near the electron stagnation point. Measurements were made southward of the X-line as determined by southward directed ion and electron jets. We show that electrostatic wave generation is due to magnetosheath electron beams formed by the electron jets as they interact with a cold background plasma and more energetic population of magnetospheric electrons. On the magnetosphere side of the X-line the electron beams are accompanied by a strong perpendicular electron temperature anisotropy, which is shown to be the source of an observed rising-tone whistler mode chorus event. We show that the apex of the chorus event and the onset of electrostatic waves coincide with the opening of magnetic field lines at the electron stagnation point.

1234567 1 - 50 of 372
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf