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Jacewicz, Marek
Publications (10 of 46) Show all publications
Andersson Sundén, E., Gustavsson, C., Hjalmarsson, A., Jacewicz, M., Lantz, M., Marciniewski, P., . . . Lundén, K. (2019). Citizen Science and Radioactivity. Nuclear Physics News, 29(2), 25-28
Open this publication in new window or tab >>Citizen Science and Radioactivity
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2019 (English)In: Nuclear Physics News, ISSN 1050-6896, Vol. 29, no 2, p. 25-28Article in journal (Other (popular science, discussion, etc.)) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-401547 (URN)10.1080/10619127.2019.1603559 (DOI)
Available from: 2020-01-08 Created: 2020-01-08 Last updated: 2020-01-23Bibliographically approved
Eriksson, J., Jacewicz, M. & Ruber, R. (2019). Cryosystem for DC spark experiments: Construction and acceptance tests. Uppsala University
Open this publication in new window or tab >>Cryosystem for DC spark experiments: Construction and acceptance tests
2019 (English)Report (Other academic)
Place, publisher, year, edition, pages
Uppsala University, 2019. p. 16
Series
FREIA Report ; 2019/02
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-396971 (URN)
Available from: 2019-11-12 Created: 2019-11-12 Last updated: 2019-11-18Bibliographically approved
Jacewicz, M. (2019). Dark currents studies with the Uppsala X-band Spectrometer at XBox test stand at CERN.
Open this publication in new window or tab >>Dark currents studies with the Uppsala X-band Spectrometer at XBox test stand at CERN
2019 (English)Report (Other academic)
Abstract [en]

Vacuum arcs is the phenomenon which limits the performance of normal conducting acceleratorcavities. It closely depends on electron field emission, which is consider a precursor for the creationof a vacuum discharge. These processes are still not fully understood, but we know that theydepend on the physical properties of the surfaces and bulk materials used in the acceleratorstructures. We need to come at these problems with a multidisciplinary approach, comprisingaccelerator, material and surface physics, for both experimental and theoretical analysis.The field emission current emitted during operation of the RF cavity is typically refer to as thedark current. Behavior of the dark current can give useful information about changes inside thestructure during conditioning and thus into the physics of the vacuum arcs. The Uppsala groupuses a magnetic spectrometer to look at the changes, both spatially on the screen and by measuringthe energy spectrum of the escaping electrons during conditioning of CLIC X-band structuresin dedicated high-power RF test stand at CERN. The spectrometer was originally designedto measure the electrons from the breakdown events with much higher intensities than the darkcurrent signals. In this paper we present the attempt to measure the dark current with the samesetup.

Publisher
p. 7
Series
FREIA Report ; 2019/04
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-392193 (URN)
Available from: 2019-08-30 Created: 2019-08-30 Last updated: 2019-09-03Bibliographically approved
Hamberg, M., Vargas Catalan, E., Karlsson, M., Dancila, D., Rydberg, A., Ögren, J., . . . Vartiainen, I. (2017). Dielectric Laser Acceleration Setup Design, Grating Manufacturing and Investigations Into Laser Induced RF Cavity Breakdowns. In: Proceedings of FEL2017, Santa Fe, NM, USA: . Paper presented at 38th International Free-Electron Laser Conference, Santa Fe, 20-25 Aug..
Open this publication in new window or tab >>Dielectric Laser Acceleration Setup Design, Grating Manufacturing and Investigations Into Laser Induced RF Cavity Breakdowns
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2017 (English)In: Proceedings of FEL2017, Santa Fe, NM, USA, 2017Conference paper, Published paper (Refereed)
National Category
Accelerator Physics and Instrumentation Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-336087 (URN)978-3-95450-179-3 (ISBN)
Conference
38th International Free-Electron Laser Conference, Santa Fe, 20-25 Aug.
Available from: 2017-12-12 Created: 2017-12-12 Last updated: 2017-12-14Bibliographically approved
Jacewicz, M., Ziemann, V., Ekelöf, T., Dubrovskiy, A. & Ruber, R. (2016). Spectrometers for RF breakdown studies for CLIC.
Open this publication in new window or tab >>Spectrometers for RF breakdown studies for CLIC
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2016 (English)Report (Other academic)
Abstract [en]

A e+e- collider of several TeV energy will be needed for the precision studies of any new physics discovered atthe LHC collider at CERN.  One promising candidate is CLIC, a linear collider which is based on a two-beam acceleration scheme that efficiently solves the problem of power distribution to the acceleration structures. The phenomenon that currently prevents achieving highaccelerating gradients in high energy accelerators such asthe CLIC is the electrical breakdown at very high electrical field.The ongoing experimental work within the CLIC collaboration is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. In order to validate the feasibility of accelerating structures and observe the characteristics of the vacuum discharges and their eroding effects on the structure two dedicated spectrometers are now commissioned at the high-power test-stands at CERN. First, the so called Flashbox has opened up a possibility for non-invasive studies of  the emitted breakdown currents during two-beam acceleration experiments. It gives an unique possibility to measure the energy of electrons and ions in combination withthe arrival time spectra and to put that in context with accelerated beam, which is not possible at any of the other existing test-stands.The second instrument, a spectrometer for detection of the dark and breakdown currents, is operated at one of the 12 GHz stand-alone test-stands at CERN.  Built for high repetition rate operation it can measure the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. Two new analysis tools: discharge impedance tracking and tomographic image reconstruction, applied to the data from the spectrometer make possible for the first time to obtain the location of the breakdown inside the structure both in the transversal and longitudinal direction thus giving a more complete picture of the vacuum breakdown phenomenon.

Series
FREIA Report ; 2016/4
Keywords
CLIC, X-Band, Accelerating structures, RF breakdowns
National Category
Accelerator Physics and Instrumentation
Research subject
Physics; Engineering Science with specialization in Microwave Technology
Identifiers
urn:nbn:se:uu:diva-282007 (URN)
Available from: 2016-04-01 Created: 2016-04-01 Last updated: 2016-09-27Bibliographically approved
Jacewicz, M., Ziemann, V., Ekelöf, T., Dubrovskiy, A. & Ruber, R. (2016). Spectrometers for RF breakdown studies for CLIC. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 828, 63-71
Open this publication in new window or tab >>Spectrometers for RF breakdown studies for CLIC
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2016 (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. 828, p. 63-71Article in journal (Refereed) Published
Abstract [en]

An e(+)e(-) collider of several TeV energy will be needed for the precision studies of any new physics discovered at the LHC collider at CERN. One promising candidate is CLIC, a linear collider which is based on a two-beam acceleration scheme that efficiently solves the problem of power distribution to the acceleration structures. The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC is the electrical breakdown at very high electrical field. The ongoing experimental work within the CLIC collaboration is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. In order to validate the feasibility of accelerating structures and observe the characteristics of the vacuum discharges and their eroding effects on the structure two dedicated spectrometers are now commissioned at the high-power test-stands at CERN. First, the so called Flashbox has opened up a possibility for non-invasive studies of the emitted breakdown currents during two-beam acceleration experiments. It gives a unique possibility to measure the energy of electrons and ions in combination with the arrival time spectra and to put that in context with accelerated beam, which is not possible at any of the other existing test-stands. The second instrument, a spectrometer for detection of the dark and breakdown currents, is operated at one of the 12 GHz stand-alone test-stands at CERN. Built for high repetition rate operation it can measure the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. Two new analysis tools: discharge impedance tracking and tomographic image reconstruction, applied to the data from the spectrometer make possible for the first time to obtain the location of the breakdown inside the structure both in the transversal and longitudinal direction thus giving a more complete picture of the vacuum breakdown phenomenon.

Keywords
CLIC; X-Band; Accelerating structures; RF breakdowns
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-293058 (URN)10.1016/j.nima.2016.05.031 (DOI)000377399700009 ()
Funder
Swedish Research CouncilKnut and Alice Wallenberg Foundation
Available from: 2016-05-11 Created: 2016-05-11 Last updated: 2017-11-30Bibliographically approved
Bhattacharyya, A., Dancila, D., Ekelöf, T., Eriksson, J., Fransson, K., Gajewski, K., . . . Ziemann, V. (2015). ESS RF Source and Spoke Cavity Test Plan.
Open this publication in new window or tab >>ESS RF Source and Spoke Cavity Test Plan
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2015 (English)Report (Other academic)
Abstract [en]

This report describes the test plan for the first high power RF source, ESS prototype double spoke cavity and ESS prototype cryomodule at the FREIA Laboratory.

Publisher
p. 13
Series
FREIA Report ; 2015/01
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-246774 (URN)
Available from: 2015-03-10 Created: 2015-03-10 Last updated: 2017-01-25Bibliographically approved
Olvegård, M., Bhattacharyya, A., Dancila, D., Ekelöf, T., Eriksson, J., Fransson, K., . . . Yogi, R. (2015). PROGRESS AT THE FREIA LABORATORY. In: Proceedings of IPAC'15: . Paper presented at IPAC'15, the sixth International Particle Accelerator Conference, Virginia, USA, May 3-8, 2015. JACoW: The Joint Accelerator Conferences Website
Open this publication in new window or tab >>PROGRESS AT THE FREIA LABORATORY
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2015 (English)In: Proceedings of IPAC'15, JACoW: The Joint Accelerator Conferences Website , 2015Conference paper, Published paper (Refereed)
Abstract [en]

The FREIA Facility for Research Instrumentation and Accelerator Development at Uppsala University, Sweden, has reached the stage where the testing of superconducting cavities for the European Spallation Source (ESS) is starting. The new helium liquefaction plant has been commissioned and now supplies a custom-made, versatile horizontal cryostat, HNOSS, with liquid helium at up to 140 l/h. The cryostat has been designed and built to house up to two accelerating cavities, or, later on, other superconducting equipment such as magnets or crab cavities. A prototype cavity for the spoke section of the ESS linac will arrive mid 2015 for high-power testing in the horizontal cryostat. Two tetrode-based commercial RF power stations will deliver 400 kW peak power each, at 352 MHz, to the cavity through an RF distribution line developed at FREIA. In addition, significant progress has been made with in-house development of solid state amplifier modules and powercombiners for future use in particle accelerators. We report here on these and other ongoing activities at the FREIA laboratory.

Place, publisher, year, edition, pages
JACoW: The Joint Accelerator Conferences Website, 2015
National Category
Accelerator Physics and Instrumentation Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-263956 (URN)
Conference
IPAC'15, the sixth International Particle Accelerator Conference, Virginia, USA, May 3-8, 2015
Available from: 2015-10-05 Created: 2015-10-05 Last updated: 2017-01-25Bibliographically approved
Pyszniak, A., Calén, H., Fransson, K. E. I., Fridén, C.-J., Hellbeck, E., Jacewicz, M., . . . Rudy, Z. (2014). A pellet tracking system for the PANDA experiment. Hyperfine Interactions, 229(1-3), 159-163
Open this publication in new window or tab >>A pellet tracking system for the PANDA experiment
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2014 (English)In: Hyperfine Interactions, ISSN 0304-3843, E-ISSN 1572-9540, Vol. 229, no 1-3, p. 159-163Article in journal (Refereed) Published
Abstract [en]

Frozen microspheres of hydrogen (pellets) will be one of the target types for the future hadron physics experiment PANDA at FAIR (GSI, Darmstadt, Germany) [1]. Pellets with a diameter of 25- mum are generated about 3 meters above the interaction region, to which they travel with a velocity around 80 m/s inside a narrow pipe. The interaction region is defined by the overlap of the pellet stream and the accelerator beam and has a size of a few millimeters. One would like to know the interaction point more precisely, to have better possibilities to reconstruct particle tracks and events e.g. in charmonium decay studies. One would also like to suppress background events that do not originate in a pellet, but e.g. may occur in rest gas, that is present in the beam pipe. A solution is provided by the presented pellet tracking system together with a target operation mode that provides one and only one pellet in the interaction region most of the time. The goal is to track individual pellets in order to know their position with a resolution of a few tenths of a millimeter at the time of an interaction. The system must also be highly efficient and provide tracking information for essentially all pellets that pass the interaction region. Presented results from the design studies show that the goals can be fulfilled by this solution.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-239587 (URN)10.1007/s10751-014-1052-5 (DOI)000343925100022 ()14767131 (PubMedID)
Available from: 2014-12-30 Created: 2014-12-29 Last updated: 2017-12-05Bibliographically approved
Jacewicz, M., Fransson, K. & Hermansson, L. (2014). Estimation of radiation levels during high power RF cavity tests in FREIA. Uppsala: Department of Physics and Astronomy, Uppsala University
Open this publication in new window or tab >>Estimation of radiation levels during high power RF cavity tests in FREIA
2014 (English)Report (Other academic)
Place, publisher, year, edition, pages
Uppsala: Department of Physics and Astronomy, Uppsala University, 2014. p. 17
Series
FREIA Report ; 2014-01
National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:uu:diva-216849 (URN)
Available from: 2014-01-27 Created: 2014-01-27 Last updated: 2014-01-28Bibliographically approved
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