Study of gamma-ray detector performance of Cd1-xZnxTe crystal treated by different etchants

1996 ◽  
Author(s):  
Henry Chen ◽  
Stephen U. Egarievwe ◽  
Z. Hu ◽  
J. Tong ◽  
Detang T. Shi ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detector Performance ◽  
Gamma Ray Detector

Defects in Silver-Doped Mercuric Iodide Crystals and their Effect on X-Ray and Gamma-Ray Detector Performance

1993 ◽  
Vol 302 ◽  
Author(s):  
R. B. James ◽  
X. J. Bao ◽  
T. E. Schlesinger ◽  
A. Y. Cheng ◽  
V. M. Gerrish
Keyword(s):  
Gamma Ray ◽  
Electrical Contacts ◽  
Source Material ◽  
Broad Emission Band ◽  
Interfacial Region ◽  
Mercuric Iodide ◽  
Detector Performance ◽  
X Ray ◽  
Silver Silver ◽  
Gamma Ray Detector

ABSTRACTThe processing steps associated with purification of source material, crystal growth, and attachment of electrical contacts can introduce defects into mercuric iodide (HgI2) that degrade the performance of detectors. We have employed low-temperature photoluminescence (PL) spectroscopy to study radiative recombination centers in the interfacial region between a thin semitransparent film of silver and mercuric iodide. The Ag film was found to introduce a new broad emission band centered at 5490 Å in the photoluminescence spectrum of HgI2. This PL feature can be used as a signature to identify the existence of Ag as a contaminant in HgI2 crystals and detectors. Experiments were also conducted on mercuric iodide surfaces that had been doped with silver, and the results showed that Ag is a rapid diffuser in bulk HgI2. Detectors with silver electrodes were also fabricated and tested using an americium-241 gamma-ray source. Large increases in the leakage currents were observed for the Ag-doped HgI2 devices, indicated that Ag impurities are electrically active in HgI2. These measurements show that silver is unacceptable as an electrode material for mercuric iodide x-ray and gamma-ray detector applications. In addition, they reveal that caution must be taken during handling of mercuric iodide source material, crystals, and detectors to avoid contact with silver, silver compounds, or with any material that contains silver as a contaminant.

Device Simulation of a Unipolar Gamma-Ray Detector

1997 ◽  
Vol 487 ◽  
Author(s):  
E. Y. Lee ◽  
J. C. Lund ◽  
N. R. Hilton ◽  
B. A. Brunett ◽  
R. B. James
Keyword(s):  
Gamma Ray ◽  
Three Dimensional ◽  
Pulse Height ◽  
Device Simulation ◽  
Design Parameters ◽  
Internal Electric Field ◽  
Successive Overrelaxation ◽  
Detector Performance ◽  
Dimensional Simulation ◽  
Gamma Ray Detector

AbstractThe pulse height spectra from a new kind of unipolar gamma-ray detectors were predicted using a new three-dimensional simulation program developed at Sandia National Laboratories. The detectors were fabricated at Sandia and RMD Inc., and tested at Sandia. They were fabricated from Cd1-x.ZnxTe crystals and they were electron-transport-only devices. For the simulation, a successive overrelaxation method was used to determine the three-dimensional internal electric field within a detector, and to find the weighting potentials for the anode and the cathode. Uniform irradiation and ionization from a 137Cs source was assumed, and the charge transport and the signal induction within the detector were numerically computed using the appropriate materials and design parameters. The simulation gave excellent agreement with experimental pulse height spectra, and it demonstrated the power of such a simulation to correlate the materials parameters and the device design to the actual detector performance.

scholarly journals The STACEE ground-based gamma-ray detector

2005 ◽  
Author(s):  
D.M. Gingrich ◽  
L.M. Boone ◽  
D. Bramel ◽  
J. Carson ◽  
C.E. Covault ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Detector
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