Current Status of AIST X-ray-Absorption-Spectroscopy (XAFS) Instrument with 100-Pixel Superconducting-Tunnel-Junction Array Detector

2014 ◽  
Vol 176 (3-4) ◽  
pp. 604-609 ◽  
Author(s):  
S. Shiki ◽  
M. Ukibe ◽  
N. Matsubayashi ◽  
N. Zen ◽  
M. Koike ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Tunnel Junction ◽  
Current Status ◽  
Array Detector ◽  
Superconducting Tunnel Junction ◽  
X Ray ◽  
Junction Array ◽  
X Ray Absorption

Local atomic structure analysis around Mg atom doped in GaN by X-ray absorption spectroscopy and spectrum simulations

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
Noritake Isomura ◽  
Yasuji Kimoto
Keyword(s):  
Absorption Spectroscopy ◽  
Density Functional ◽  
High Sensitivity ◽  
High Energy ◽  
High Energy Resolution ◽  
Array Detector ◽  
Superconducting Tunnel Junction ◽  
Substitutional Site ◽  
X Ray ◽  
X Ray Absorption

The identification of the incorporated site of magnesium (Mg) and hydrogen (H) required for p-type formation in gallium nitride (GaN) power devices has been demonstrated by X-ray absorption spectroscopy (XAS). In this study, the fluorescence line of Mg with 3 × 1019 atoms cm−3 was successfully separated from that of Ga using a superconducting tunnel junction array detector with high sensitivity and high energy resolution, and consequently the Mg K-edge XAS spectra of such dilute samples were obtained. The site of Mg atoms incorporated into the GaN lattice was identified as the Ga substitutional site by comparing the experimental XAS spectrum with the simulated spectra calculated by density functional theory. In addition, the presence or absence of H around Mg can be determined through distinctive characteristics expected from the spectrum simulations.

scholarly journals Superconducting Tunnel Junction Array Development for High-Resolution Energy-Dispersive X-ray Spectroscopy

1998 ◽  
Vol 4 (6) ◽  
pp. 616-621 ◽  
Author(s):  
S. Friedrich ◽  
C.A. Mears ◽  
B. Nideröst ◽  
L.J. Hiller ◽  
M. Frank ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Tunnel Junction ◽  
Count Rate ◽  
Energy Dispersive ◽  
Superconducting Tunnel Junction ◽  
X Rays ◽  
Detector Arrays ◽  
X Ray ◽  
Junction Array ◽  
Stj Detector

Cryogenic energy-dispersive X-ray detectors are being developed because of their superior energy resolution (10 eV FWHM for keV X-rays) compared to that achieved in semiconductor energy-dispersive spectrometry (EDS) systems. So far, their range of application is limited because of their comparably small size and low count rate. We present data on the development of superconducting tunnel junction (STJ) detector arrays to address both of these issues. A single STJ detector has a resolution of around 10 eV below 1 keV and can be operated at count rates of the order 10,000 counts/sec. We show that the simultaneous operation of several STJ detectors does not dimish their energy resolution significantly, and it increases the detector area and the maximum count rate by a factor given by the total number of independent channels.

Development of a superconducting-tunnel-junction array for x-ray astronomy

1997 ◽  
Author(s):  
Roland H. den Hartog ◽  
Anthony J. Peacock ◽  
Peter Verhoeve ◽  
Fred A. Jansen ◽  
J. Verveer ◽  
...  
Keyword(s):  
Tunnel Junction ◽  
Superconducting Tunnel Junction ◽  
X Ray ◽  
Junction Array
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