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001-es BibID:	BIBFORM102741
035-os BibID:	(Wos)000460814000017 (Scopus)85063485972
Első szerző:	Gall, Amy C.
Cím:	EBIT Observation of Ar Dielectronic Recombination Lines near the Unknown Faint X-Ray Feature Found in the Stacked Spectrum of Galaxy Clusters / Gall, Amy C., Foster Adam R., Silwal, Roshani, Dreiling, Joan M., Borovik, Alexander, Kilgore, Ethan, Ajello, Marco, Gillaspy, John D., Ralchenko, Yuri, Takács, Endre
Dátum:	2019
ISSN:	1538-4357
Megjegyzések:	Motivated by possible atomic origins of the unidentified emission line detected at 3.55?3.57 keV in a stacked spectrum of galaxy clusters, an electron beam ion trap (EBIT) was used to investigate the resonant dielectronic recombination (DR) process in highly charged argon ions as a possible contributor to the emission feature. The He-like Ar DR-induced transition 1s2 2l?1s2l3l· was suggested to produce a 3.62 keV photon near the unidentified line at 3.57 keV and was the starting point of our investigation. The collisional-radiative model NOMAD was used to create synthetic spectra for comparison with both our EBIT measurements and with spectra produced with the AtomDB database/Astrophysical Plasma Emission Code (APEC) used in the Bulbul et al. work. Excellent agreement was found between the NOMAD and EBIT spectra, providing a high level of confidence in the atomic data used. Comparison of the NOMAD and APEC spectra revealed a number of missing features in the AtomDB database near the unidentified line. At an electron temperature of Te = 1.72 keV, the inclusion of the missing lines in AtomDB increases the total flux in the 3.5?3.66 keV energy band by a factor of 2. While important, this extra emission is not enough to explain the unidentified line found in the galaxy cluster spectra.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk atomic processesline: identificationmethods: laboratory: atomictechniques: spectroscopicX-rays: galaxies: clusters
Megjelenés:	The Astrophysical Journal. - 872 : 2 (2019), p. 194-202. -
További szerzők:	Foster, Adam R. Silwal, Roshani Dreiling, Joan M. Borovik, Alexander Kilgore, Ethan Ajello, Marco Gillaspy, John Dale Ralchenko, Yuri Takács Endre (1965-) (fizikus)
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001-es BibID:	BIBFORM104088
035-os BibID:	(cikkazonosító)123107 (Wos)000504106500011 (Scopus)85076713478
Első szerző:	Szypryt, Paul
Cím:	A transition-edge sensor-based x-ray spectrometer for the study of highly charged ions at the National Institute of Standards and Technology electron beam ion trap / P. Szypryt, G. C. O`Neil, E. Takacs, J. N. Tan, S. W. Buechele, A. S. Naing, D. A. Bennett, W. B. Doriese, M. Durkin, J. W. Fowler, J. D. Gard, G. C. Hilton,K. M. Morgan, C. D. Reintsema, D. R. Schmidt, D. S. Swetz, J. N. Ullom, Yu. Ralchenko
Dátum:	2019
ISSN:	0034-6748
Megjegyzések:	We report on the design, commissioning, and initial measurements of a Transition-Edge Sensor (TES) x-ray spectrometer for the Electron Beam Ion Trap (EBIT) at the National Institute of Standards and Technology (NIST). Over the past few decades, the NIST EBIT has produced numerous studies of highly charged ions in diverse fields such as atomic physics, plasma spectroscopy, and laboratory astrophysics. The newly commissioned NIST EBIT TES Spectrometer (NETS) improves the measurement capabilities of the EBIT through a combination of high x-ray collection efficiency and resolving power. NETS utilizes 192 individual TES x-ray microcalorimeters (166/192 yield) to improve upon the collection area by a factor of similar to 30 over the 4-pixel neutron transmutation doped germanium-based microcalorimeter spectrometer previously used at the NIST EBIT. The NETS microcalorimeters are optimized for the x-ray energies from roughly 500 eV to 8000 eV and achieve an energy resolution of 3.7 eV-5.0 eV over this range, a more modest (<2x) improvement over the previous microcalorimeters. Beyond this energy range, NETS can operate with various trade-offs, the most significant of which are reduced efficiency at lower energies and being limited to a subset of the pixels at higher energies. As an initial demonstration of the capabilities of NETS, we measured transitions in He-like and H-like O, Ne, and Ar as well as Ni-like W. We detail the energy calibration and data analysis techniques used to transform detector counts into x-ray spectra, a process that will be the basis for analyzing future data.
Tárgyszavak:	Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Review Of Scientific Instruments. - 90 : 12 (2019), p. 1-19. -
További szerzők:	O'Neil, G. C. Takács Endre (1965-) (fizikus) Tan, J. N. Buechele, S. W. Naing, A. S. Bennett, D. A. Doriese, W. B. Durkin, M. Fowler, J. W. Gard, J. D. Hilton, G. C. Morgan, K. M. Reintsema, C. D. Schmidt, D. R. Swetz, D. S. Ullom, J. N. Ralchenko, Yuri
Pályázati támogatás:	1806494 Egyéb
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