uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Nordgren, Joseph
Alternative names
Publications (10 of 94) Show all publications
Zhang, L., Li, X., Augustsson, A., Lee, C. M., Rubensson, J.-E., Nordgren, J., . . . Guo, J.-H. -. (2017). Revealing the electronic structure of LiC6 by soft X-ray spectroscopy. Applied Physics Letters, 110(10), Article ID 104106.
Open this publication in new window or tab >>Revealing the electronic structure of LiC6 by soft X-ray spectroscopy
Show others...
2017 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 110, no 10, article id 104106Article in journal (Refereed) Published
Abstract [en]

The electronic structure of LiC6 has been investigated by soft X-ray absorption and emission spectroscopies. The results reveal that upon full lithiation of graphite, the Li 2s electrons are transferred into the carbon pi* states in a near rigid-band behavior, resulting in the increased density of states near E-F and the shift of sigma* states to lower energies. In addition, the resonant inelastic X-ray scattering spectra of LiC6 do not show strong dispersive features as that of graphite, indicating that the crystal momentum is not conserved during the scattering process due to the delocalization of electrons in the intermediate state.

National Category
Physical Sciences Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-320659 (URN)10.1063/1.4978432 (DOI)000397871800063 ()
Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2017-06-30Bibliographically approved
Rohringer, N., Kimberg, V., Weninger, C., Sanchez-Gonzalez, A., Lutman, A., Maxwell, T., . . . Rubensson, J.-E. (2016). Stimulated X-Ray Raman Scattering with Free-Electron Laser Sources. In: X-RAY LASERS 2014: . Paper presented at 14th International Conference on X-Ray Lasers, MAY 26-30, 2014, Colorado State Univ, Fort Collins, CO (pp. 201-207).
Open this publication in new window or tab >>Stimulated X-Ray Raman Scattering with Free-Electron Laser Sources
Show others...
2016 (English)In: X-RAY LASERS 2014, 2016, p. 201-207Conference paper, Published paper (Refereed)
Abstract [en]

Stimulated electronic x-ray Raman scattering is the building block for several proposed x-ray pump probe techniques, that would allow the study of electron dynamics at unprecedented timescales. We present high spectral resolution data on stimulated electronic x-ray Raman scattering in a gas sample of neon using a self-amplified spontaneous emission x-ray free-electron laser. Despite the limited spectral coherence and broad bandwidth of these sources, high-resolution spectra can be obtained by statistical methods, opening the path to coherent stimulated x-ray Raman spectroscopy. An extension of these ideas to molecules and the results of a recent experiment in CO are discussed.

Series
Springer Proceedings in Physics, ISSN 0930-8989 ; 169
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-300141 (URN)10.1007/978-3-319-19521-6_26 (DOI)000378036600026 ()9783319195216; 9783319195209 (ISBN)
Conference
14th International Conference on X-Ray Lasers, MAY 26-30, 2014, Colorado State Univ, Fort Collins, CO
Available from: 2016-08-03 Created: 2016-08-03 Last updated: 2016-08-03Bibliographically approved
Modin, A., Suzuki, M.-T., Vegelius, J., Yun, Y., Shuh, D. K., Werme, L., . . . Butorin, S. M. (2015). 5 f-Shell correlation effects in dioxides of light actinides studied by O 1s x-ray absorption and emission spectroscopies and first-principles calculations. Journal of Physics: Condensed Matter, 27(31), Article ID 315503.
Open this publication in new window or tab >>5 f-Shell correlation effects in dioxides of light actinides studied by O 1s x-ray absorption and emission spectroscopies and first-principles calculations
Show others...
2015 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 27, no 31, article id 315503Article in journal (Refereed) Published
Abstract [en]

Soft x-ray emission and absorption spectroscopic data are reported for the O 1s region of a single crystal of UO2, a polycrystalline NpO2 sample, and a single crystal of PuO2. The experimental data are interpreted using first-principles correlated-electron calculations within the framework of the density functional theory with added Coulomb U interaction (DFT+U). A detailed analysis regarding the origin of different structures in the x-ray emission and x-ray absorption spectra is given and the effect of varying the intra-atomic Coulomb interaction-U for the 5f electrons is investigated. Our data indicate that O 1s x-ray absorption and emission spectroscopies can, in combination with DFT+U calculations, successfully be used to study 5f-shell Coulomb correlation effects in dioxides of light actinides. The values for the Coulomb U parameter in these dioxides are derived to be in the range of 4-5 eV.

Keywords
actinide dioxides, x-ray spectroscopy, DFT plus U
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-260803 (URN)10.1088/0953-8984/27/31/315503 (DOI)000358595500007 ()26202182 (PubMedID)
Funder
Swedish Research Council
Available from: 2015-08-31 Created: 2015-08-25 Last updated: 2017-12-04Bibliographically approved
Yin, Z., Peters, H. B., Hahn, U., Agåker, M., Hage, A., Reininger, R., . . . Techert, S. (2015). A new compact soft x-ray spectrometer for resonant inelastic x-ray scattering studies at PETRA III. Review of Scientific Instruments, 86(9), Article ID 093109.
Open this publication in new window or tab >>A new compact soft x-ray spectrometer for resonant inelastic x-ray scattering studies at PETRA III
Show others...
2015 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 86, no 9, article id 093109Article in journal (Refereed) Published
Abstract [en]

We present a newly designed compact grating spectrometer for the energy range from 210 eV to 1250 eV, which would include the K alpha(1,2) emission lines of vital elements like C, N, and O. The spectrometer is based on a grazing incidence spherical varied line spacing grating with 2400 l/mm at its center and a radius of curvature of 58 542 mm. First, results show a resolving power of around 1000 at an energy of 550 eV and a working spectrometer for high vacuum (10(-4) mbar) environment without losing photon intensity.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-265597 (URN)10.1063/1.4930968 (DOI)000362573300010 ()26429431 (PubMedID)
Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2017-12-01
Englund, C.-J., Agåker, M., Fredriksson, P., Olsson, A., Johansson, N., Rubensson, J.-E. & Nordgren, J. (2015). An ultra-high vacuum chamber for scattering experiments featuring in-vacuum continuous in-plane variation of the angle between entrance and exit vacuum ports. Review of Scientific Instruments, 86(9), Article ID 095110.
Open this publication in new window or tab >>An ultra-high vacuum chamber for scattering experiments featuring in-vacuum continuous in-plane variation of the angle between entrance and exit vacuum ports
Show others...
2015 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 86, no 9, article id 095110Article in journal (Refereed) Published
Abstract [en]

A concept that enables in-vacuum continuous variation of the angle between two ports in one plane has been developed and implemented. The vacuum chamber allows for measuring scattering cross sections as a function of scattering angle and is intended for resonant inelastic X-ray scattering experiments. The angle between the ports can be varied in the range of 30 degrees-150 degrees, while the pressure change is less than 2 x 10(-10) mbars.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-265596 (URN)10.1063/1.4931041 (DOI)000362573300062 ()26429483 (PubMedID)
Funder
Knut and Alice Wallenberg Foundation
Available from: 2015-11-02 Created: 2015-11-02 Last updated: 2017-12-01
Terschlüsen, J. A., Agåker, M., Svanqvist, M., Plogmaker, S., Nordgren, J., Rubensson, J.-E., . . . Söderström, J. (2014). Measuring the temporal coherence of a high harmonic generation setup employing a Fourier transform spectrometer for the VUV/XUV. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 768, 84-88
Open this publication in new window or tab >>Measuring the temporal coherence of a high harmonic generation setup employing a Fourier transform spectrometer for the VUV/XUV
Show others...
2014 (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. 768, p. 84-88Article in journal (Refereed) Published
Abstract [en]

In this experiment we used an 800 nm laser to generate high-order harmonics in a gas cell filled with Argon. Of those photons, a harmonic with 42 eV was selected by using a time-preserving grating monochromator. Employing a modified Mach–Zehnder type Fourier transform spectrometer for the VUV/XUV it was possible to measure the temporal coherence of the selected photons to about 6 fs. We demonstrated that not only could this kind of measurement be performed with a Fourier transform spectrometer, but also with some spatial resolution without modifying the XUV source or the spectrometer.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Fourier transform spectrometer, HHG, Temporal coherence, Spatial coherence, SoftX-ray, XUV
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:uu:diva-236322 (URN)10.1016/j.nima.2014.09.040 (DOI)000344995400013 ()
Funder
Swedish Research Council, 2006-4382Swedish Research Council, 2010-4132Swedish Research Council, 2011-5036Knut and Alice Wallenberg Foundation, 2008.0108Knut and Alice Wallenberg Foundation, personal grant (JS)Carl Tryggers foundation , 12:439Carl Tryggers foundation , 13:423
Available from: 2014-11-17 Created: 2014-11-17 Last updated: 2017-12-05Bibliographically approved
Turcato, M., Gessler, P., Hauf, S., Kuster, M., Meyer, M., Nordgren, J., . . . Youngman, C. (2014). Small area detectors at the European XFEL. Journal of Instrumentation, 9, C05063
Open this publication in new window or tab >>Small area detectors at the European XFEL
Show others...
2014 (English)In: Journal of Instrumentation, ISSN 1748-0221, E-ISSN 1748-0221, Vol. 9, p. C05063-Article in journal (Refereed) Published
Abstract [en]

The detectors to be used at the European XFEL have to deal with the unique time structure of the machine, delivering up to 2700 pulses, with a repetition rate of 4.5 MHz, ten times per second, the very high photon flux and the need to combine single-photon sensitivity and a large dynamic range. This represents a challenge not only for the large-area 2D imaging detectors but also for the smaller-area detectors and makes the use of standard commercial devices impossible. Dedicated solutions are therefore envisaged for small imaging- or strip-detectors. In this contribution the focus is put on two particular small-area detector solutions which are planned to be used at the European XFEL, a strip detector for hard X-rays (with energy 3 < E < 25keV) and an imaging detector for soft X-rays (0.25 < E < 3keV). Hard X-rays photon-beam diagnostics as well as hard X-ray absorption and emission spectroscopy at the European XFEL make use of strip detectors as detectors for beam spectrometers or as energy-dispersive detectors in combination with an energy-dispersive element. The European XFEL is establishing cooperation with the Paul Scherrer Institute in Villigen to develop a new version of the Gotthard detector best suited to the European XFEL needs. The use case and the required detector specifications are illustrated. Starting from the present detector version, the modifications planned to adapt it to the European XFEL running conditions are described. These include the capability of running at an increased rate and to provide a veto signal to the large 2D imaging detectors, in order to be able to remove non-interesting images already at early stages of the DAQ system. In another particular application, resonant inelastic X-ray scattering, a Micro-Channel Plate detector matched to a delay-line readout is foreseen to be used. In this case the European XFEL is aiming for a highly customized solution provided by the German company Surface Concept. The use case is described, the science-driven detector specifications are illustrated and the expected detector performance is shown.

Keywords
X-ray detectors, Spectrometers
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-231447 (URN)10.1088/1748-0221/9/05/C05063 (DOI)000340036100063 ()
Available from: 2014-09-10 Created: 2014-09-08 Last updated: 2017-12-05Bibliographically approved
Shuh, D. K., Batista, E. R., Butorin, S. M., Clark, D. L., Guo, J., Keith, J. M., . . . Tyliszczak, T. (2013). Actinide science the Richard G. Haire way: Inspiring, innovative, energetic, and sleeves-up. Paper presented at 245th National Spring Meeting of the American-Chemical-Society (ACS), APR 07-11, 2013, New Orleans, LA, USA. Abstract of Papers of the American Chemical Society, 245, 48-NUCL
Open this publication in new window or tab >>Actinide science the Richard G. Haire way: Inspiring, innovative, energetic, and sleeves-up
Show others...
2013 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245, p. 48-NUCL-Article in journal, Meeting abstract (Other academic) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-210344 (URN)000324303602646 ()
Conference
245th National Spring Meeting of the American-Chemical-Society (ACS), APR 07-11, 2013, New Orleans, LA, USA
Available from: 2013-11-06 Created: 2013-11-05 Last updated: 2017-12-06Bibliographically approved
Butorin, S. M., Shuh, D. K., Kvashnina, K. O., Guo, J., Werme, L. & Nordgren, J. (2013). Chemical Reduction of Actinides Probed by Resonant Inelastic X-ray Scattering. Analytical Chemistry, 85(23), 11196-11200
Open this publication in new window or tab >>Chemical Reduction of Actinides Probed by Resonant Inelastic X-ray Scattering
Show others...
2013 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 85, no 23, p. 11196-11200Article in journal (Refereed) Published
Abstract [en]

The study addresses the possibilities of immobilizing the mobile species of actinides in the geosphere using metallic iron. Sorption on corroding iron is well-known, but there have been uncertainties with regard to the possibilities of reducing the actinyl species to sparingly soluble oxides and, thereby, permanently immobilizing them. Resonant inelastic X-ray scattering (RIXS) measurements at the actinide 5d edges on Fe foils exposed to uranium(VI) and neptunium(V) solutions in groundwater unambigiously indicate reduction of actinides to, respectively, uranium(IV) and neptunium(IV) on iron surfaces. The reduction manifests itself in an appearance of distinct specific signatures of uranium(IV) and neptunium(IV) in the RIXS profile of 5f-5f excitations. Such signatures and RIXS intensity/cross-section behavior with varying energy of incident photons can be reproduced by model atomic-multiplet calculations of the RIXS spectra. By normalizing the RIXS signal of corresponding 5f-5f excitations to core-to-core 6p-to-5d characteristic fluorescence transitions of actinides, their reduction rates on Fe samples with different exposure to actinide solutions can be estimated. Observed reduction implies similar processes in the nuclear waste canister thus suggesting reduced probability of nuclear waste release with ground waters from the canister.

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-214022 (URN)10.1021/ac4020534 (DOI)000327999800007 ()
Available from: 2014-01-07 Created: 2014-01-07 Last updated: 2017-12-06Bibliographically approved
Nordgren, J. & Rubensson, J.-E. (2013). Resonant soft X-ray emission for studies of molecules and solids. Journal of Electron Spectroscopy and Related Phenomena, 188(SI), 3-9
Open this publication in new window or tab >>Resonant soft X-ray emission for studies of molecules and solids
2013 (English)In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 188, no SI, p. 3-9Article in journal (Refereed) Published
Abstract [en]

Resonant inelastic X-ray scattering (RIXS) has emerged as a powerful method for the study of the electronic structure of matter in various phases and ambient conditions. The selectivity offered by resonant excitation and polarization control in RIXS experiments offers rich information on excitations in molecules, liquids, and solids. The photon-in photon-out nature of RIXS makes it an interesting method in the study of ultra-high brightness FEL radiation interaction with matter. The present work offers an introductory review on the sub-key RIXS, including some historic comments.

Keywords
Soft X-ray emission, Synchrotron radiation, RIXS, X-ray Raman spectroscopy
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-208675 (URN)10.1016/j.elspec.2012.11.004 (DOI)000324008900002 ()
Available from: 2013-10-07 Created: 2013-10-07 Last updated: 2017-12-06Bibliographically approved
Organisations

Search in DiVA

Show all publications