Development of a high-resolution room-temperature compressed-xenon cylindrical ionization-chamber gamma radiation detector

1998 ◽  
Author(s):  
Gary C. Tepper ◽  
Jon R. Losee ◽  
Robert L. Palmer
Keyword(s):  
High Resolution ◽  
Gamma Radiation ◽  
Ionization Chamber ◽  
Room Temperature ◽  
Radiation Detector ◽  
Cylindrical Ionization Chamber

Very high resolution detection of gamma radiation at room-temperature using p-i-n detectors of CdZnTe and HgCdTe

1994 ◽  
Vol 41 (4) ◽  
pp. 989-992 ◽  
Author(s):  
W.J. Hamilton ◽  
D.R. Rhiger ◽  
S. Sen ◽  
M.H. Kalisher ◽  
K. James ◽  
...  
Keyword(s):  
High Resolution ◽  
Gamma Radiation ◽  
Room Temperature ◽  
Very High

scholarly journals Quaternary Semiconductor Cd1-xZnxTe1-ySey for High-Resolution, Room-Temperature Gamma-Ray Detection

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 827
Author(s):  
Sandeep K. Chaudhuri ◽  
Joshua W. Kleppinger ◽  
OmerFaruk Karadavut ◽  
Ritwik Nag ◽  
Krishna C. Mandal
Keyword(s):  
Crystal Growth ◽  
High Resolution ◽  
Charge Transport ◽  
Single Crystals ◽  
Homeland Security ◽  
Room Temperature ◽  
Gamma Ray ◽  
Radiation Detector ◽  
Growth Yield ◽  
Charge Trapping

The application of Cd0.9Zn0.1Te (CZT) single crystals, the primary choice for high-resolution, room-temperature compact gamma-ray detectors in the field of medical imaging and homeland security for the past three decades, is limited by the high cost of production and maintenance due to low detector grade crystal growth yield. The recent advent of its quaternary successor, Cd0.9Zn0.1Te1-ySey (CZTS), has exhibited remarkable crystal growth yield above 90% compared to that of ~33% for CZT. The inclusion of Se in appropriate stoichiometry in the CZT matrix is responsible for reducing the concentration of sub-grain boundary (SGB) networks which greatly enhances the compositional homogeneity and growth yield. SGB networks also host defect centers responsible for charge trapping, hence their reduced concentration ensures minimized charge trapping. Indeed, CZTS single crystals have shown remarkable improvement in electron charge transport properties and energy resolution over CZT detectors. However, our studies have found that the overall charge transport in CZTS is still limited by the hole trapping. In this article, we systematically review the advances in the CZTS growth techniques, its performance as room-temperature radiation detector, and the role of defects and their passivation studies needed to improve the performance of CZTS detectors further.

A Liquid Nitrogen Cooled Stage for STEM

1974 ◽  
Vol 32 ◽  
pp. 444-445
Author(s):  
Louis T. Germinario
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Liquid Nitrogen ◽  
Room Temperature ◽  
Objective Lens ◽  
Thermal Drift ◽  
Specimen Holder ◽  
Resolution Capability ◽  
Focal Position

A liquid nitrogen stage has been developed for the JEOL JEM-100B electron microscope equipped with a scanning attachment. The design is a modification of the standard JEM-100B SEM specimen holder with specimen cooling to any temperatures In the range ~ 55°K to room temperature. Since the specimen plane is maintained at the ‘high resolution’ focal position of the objective lens and ‘bumping’ and thermal drift la minimized by supercooling the liquid nitrogen, the high resolution capability of the microscope is maintained (Fig.4).

High-Resolution Scanning Electron Microscopy of Biological Specimens

1988 ◽  
Vol 46 ◽  
pp. 186-187
Author(s):  
M. Müller ◽  
R. Hermann
Keyword(s):  
High Resolution ◽  
Freeze Drying ◽  
Room Temperature ◽  
Structural Information ◽  
Freeze Substitution ◽  
Critical Point Drying ◽  
Sem Study ◽  
Major Factors ◽  
Structural Preservation ◽  
Preparation Techniques

Three major factors must be concomitantly assessed in order to extract relevant structural information from the surface of biological material at high resolution (2-3nm).Procedures based on chemical fixation and dehydration in graded solvent series seem inappropriate when aiming for TEM-like resolution. Cells inevitably shrink up to 30-70% of their initial volume during gehydration; important surface components e.g. glycoproteins may be lost. These problems may be circumvented by preparation techniques based on cryofixation. Freezedrying and freeze-substitution followed by critical point drying yields improved structural preservation in TEM. An appropriate preservation of dimensional integrity may be achieved by freeze-drying at - 85° C. The sample shrinks and may partially collapse as it is warmed to room temperature for subsequent SEM study. Observations at low temperatures are therefore a necessary prerequisite for high fidelity SEM. Compromises however have been unavoidable up until now. Aldehyde prefixation is frequently needed prior to freeze drying, rendering the sample resistant to treatment with distilled water.

Transition Insulator-Metal and Antiferromagnetic-Paramagnetic Cu Doped in La0.47Ca0.53MnO3

2015 ◽  
Vol 1123 ◽  
pp. 73-77 ◽  
Author(s):  
Yohanes Edi Gunanto ◽  
K. Sinaga ◽  
B. Kurniawan ◽  
S. Poertadji ◽  
H. Tanaka ◽  
...  
Keyword(s):  
High Resolution ◽  
Low Temperature ◽  
Magnetic Structure ◽  
Room Temperature ◽  
Paramagnetic Phase ◽  
Perovskite Manganites ◽  
Antiferromagnetic Phase ◽  
Temperature Transition ◽  
Cu Doping ◽  
Metal State

The study of the perovskite manganites La0.47Ca0.53Mn1-xCuxO3 with x = 0, 0.06, 0.09, and 0.13 has been done. The magnetic structure was determined using high-resolution neutron scattering at room temperature and low temperature. All samples were paramagnetic at room temperature and antiferromagnetic at low temperature. Using the SQUID Quantum Design, the samples showed that the doping of the insulating antiferromagnetic phase La0.47Ca0.53MnO3 with Cu doping resulted in the temperature transition from an insulator to metal state, and an antiferromagnetic to paramagnetic phase. The temperature transition from an insulator to metal state ranged from 23 to 100 K and from 200 to 230 K for the transition from an antiferromagnetic to paramagnetic phase.

High-pressure xenon cylindrical ionization chamber with a shielding mesh

1994 ◽  
Author(s):  
Sergey E. Ulin ◽  
Valery V. Dmitrenko ◽  
V. M. Grachev ◽  
O. N. Kondakova ◽  
S. V. Krivov ◽  
...  
Keyword(s):  
High Pressure ◽  
Ionization Chamber ◽  
Cylindrical Ionization Chamber
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