High resolution, low energy avalanche photodiode X-ray detectors

1991 ◽  
Vol 38 (2) ◽  
pp. 144-147 ◽  
Author(s):  
R. Farrell ◽  
K. Vanderpuye ◽  
G. Entine ◽  
M.R. Squillante
1971 ◽  
Vol 49 (6) ◽  
pp. 747-755 ◽  
Author(s):  
S. C. Gujrathi ◽  
J. M. d'Auria ◽  
R. G. Korteling

The lifetimes and energies associated with low-energy gamma transitions from the 93Nb(n,γ)94Nb, 107Ag(n,γ)108Ag, and 109Ag(n,γ)110Ag reactions have been studied using a high-resolution Ge(Li) X-ray spectrometer. New weak transitions are observed in the decay of 110Ag at 30.84, 38.19, 41.78, and 136.65 keV, while intense gamma transitions at 105.6, 235.8, and 266.95 keV are resolved into doublets. The half-life of the state involving the intense 117.47 keV transition in 110Ag and the 215 keV transition in 108Ag is confirmed as 36.5 ± 2.0 ns and 54 ± 8 ns, respectively, while a new delayed state associated with the gamma transition of 99.404 keV (T1/2 = 30 ± 5 ns) in 94Nb is observed for the first time. The upper limits for the half-lives involving most of the intense transitions in all the three isotopes are also reported. A level scheme is proposed and discussed for 108Ag.


2021 ◽  
Vol 16 (12) ◽  
pp. P12012
Author(s):  
H. Heo ◽  
J. Yang ◽  
J. Kang

Abstract A rotatable lutetium-yttrium-oxyorthosilicate-Geiger-mode-avalanche photodiode (LYSO-GAPD) DEXA detector that can be configured into either a normal-resolution or a high-resolution mode, was proposed and examined. A 3 × 3 × 2 mm3 LYSO was coupled to a 3 × 3 mm2 GAPD. The versatile transformation of the high-resolution mode was possible by employing the rotating controller for the DEXA detector on its own axis, and the intrinsic resolution in this mode was improved by ∼ 33% compared to the normal-resolution mode. Dual-energy X-ray spectra and imaging capabilities were evaluated in both acquisition modes. The respective peak positions of low- and high-energy-beam of normal-resolution mode (high-resolution mode) were 1330 mV (1262 mV) and 2347 mV (2267 mV). The respective peak-to-valley ratios of low- and high-energy-beam of normal-resolution mode (high-resolution mode) were ∼ 2.8 (∼ 2.9) and ∼ 1.2 (∼ 1.1). Considerable improvements in phantom images such as overall contrast and fine-spot detectability were observed in the high-resolution mode. It should be noted that spatial resolution was improved by reducing the detection-area from 3 × 3 mm2 to 2 × 3 mm2 in the high-resolution mode, but count rate was also decreased. These results demonstrated that a rotatable LYSO-GAPD DEXA detector allows to provide high versatility for both high-resolution mode and normal-resolution mode with a single detector.


2011 ◽  
Vol 6 (01) ◽  
pp. C01048-C01048 ◽  
Author(s):  
J Tous ◽  
P Horodysky ◽  
K Blazek ◽  
M Nikl ◽  
J A Mares
Keyword(s):  

2002 ◽  
Vol 09 (02) ◽  
pp. 1103-1108 ◽  
Author(s):  
L.-C. DUDA ◽  
T. SCHMITT ◽  
J. NORDGREN ◽  
G. DHALENNE ◽  
A. REVCOLEVSCHI

We have performed high-resolution inelastic X-ray emission scattering experiments at the Cu 3p-, Cu 3s-, and O 1s-resonances of the insulating cuprates CuGeO 3, CuO, La 2 CuO 4, and SrCuO 2. We introduce the novel low-energy s-edge Cu-RIXS which reveals a dd-excitation peak, which was previously unobserved due to insufficient resolution and intensity in high-energy (Cu 1s RIXS). Also, O 1s-RIXS of all cuprate sample is investigated. Surprisingly, there is a large spread in the energy loss values of the RIXS features for different compounds and we explain this by assigning the larger energy features to the occurrence of a Zhang–Rice singlet while the lower energy feature (only observed for CuGeO 3) is assigned to a dd-excitation.


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