The Fabrication of Mercuric Iodide Detectors for Use in Wavelength Dispersive X-Ray Analysers and Backscatter Photon Measurements

1982 ◽  
Vol 16 ◽  
Author(s):  
John H. Howes ◽  
John Watling
Keyword(s):  
Room Temperature ◽  
Gamma Ray ◽  
Surface Passivation ◽  
Electrical Contact ◽  
Scintillation Counter ◽  
Radiation Detectors ◽  
Nuclear Radiation ◽  
Gamma Ray Spectrometry ◽  
Mercuric Iodide ◽  
X Ray

ABSTRACTThis paper describes the fabrication of mercuric iodide nuclear radiation detectors suitable for X and gamma ray spectrometry at room temperature. The active area of the detectors studied are between 0.2 and 1.5cm sq and they are up to 0.5mm thick. The method of producing a stable electrical contact to the crystal using sputtered germanium has been studied. The X-ray resolution of a 1.5cm sq. area detector at 32 keV is 2.3 keV FWHM when operated at room temperature in conjunction with a time variant filter amplifier. A factor which is important in the fabrication of the detector is the surface passivation necessary to achieve a useful detector life.This type of detector has been used on a wavelength dispersive X-ray spectrometer for energy measurements between 10 and 100 keV. The advantages over the scintillation counter, more commonly used, is the improved resolution of the HgI2 detector and its smaller size. The analyser is primarily used for the detection of low levels of heavy metals on particulate filters. The detectors have also been used on an experimental basis for gamma ray backscatter measurements in the medical field.

The Gas Proportional Scintillation Counter as a Room-Temperature Detector For Energy-Dispersive X-Ray Fluorescence Analysis

1981 ◽  
Vol 25 ◽  
pp. 39-44 ◽  
Author(s):  
C. A. N. Conde ◽  
L. F. Requicha Ferreira ◽  
A. J. de Campos
Keyword(s):  
Room Temperature ◽  
Scintillation Counter ◽  
Fluorescence Analysis ◽  
Energy Dispersive ◽  
X Rays ◽  
Mercuric Iodide ◽  
X Ray ◽  
Temperature Detector ◽  
Portable Instruments ◽  
Physical Principles

AbstractA review of the basic physical principles of the gas proportional scintillation counter is presented. Its performance is discussed and compared with that of other room-temperature detectors in regard to applications to portable instruments for energy-dispersive X-ray fluorescence analysis. It is concluded that the gas proportional scintillation counter is definitely superior to all other room-temperature detectors, except the mercuric iodide (HgI2) detector. For large areas or soft X-rays it is also superior to the HgI2 detector.

Progress in Cd1−xZnxTe (CZT) Radiation Detectors

1994 ◽  
Vol 299 ◽  
Author(s):  
J. F. Butler ◽  
F. P. Doty ◽  
B. Apotovsky ◽  
S. J. Friesenhahn ◽  
C. Lingren
Keyword(s):  
Room Temperature ◽  
Ohmic Contacts ◽  
Gamma Ray ◽  
Surface Effect ◽  
Growth Parameters ◽  
Radiation Detectors ◽  
Imaging Data ◽  
Detector Arrays ◽  
X Ray ◽  
First Time

AbstractResults of a program to improve the performance of Cd1−xZnxTe detectors by adjusting growth parameters to achieve low-strain, high purity low defect crystals, investigating surface effect phenomena and contacting methods, and establishing reproducible manufacturing methods are reviewed and discussed. Processing and fabrication methods were developed which are applicable throughout the composition range. Energy spectra for room temperature Cd1−xZnxTe detectors exhibit resolutions (FWHM) from 2.16 keV at 14 keV to 6.9 keV at 122 keV. An energy resolution of 910 eV at 5.9 keV was achieved at −25 C. Stable ohmic contacts and gamma ray detection for ZnTe are reported for the first time. Applications of Cd1−xZnxTe to nuclear medicine and X-ray fluorescence are discussed. New gamma ray imagers using Cd1-−ZnxTe detector arrays are described, and imaging data for a 32 × 32 monolithic array of 1 mm2 elements on a 42mm × 42mm substrate are presented.

A New X-Ray Spectroscopy Concept-Room Temperature Mercuric Iodide with Peltier-Cooled Preamplification

1978 ◽  
Vol 22 ◽  
pp. 461-472 ◽  
Author(s):  
G.C. Huth ◽  
A.J. Dabrowski ◽  
M. Singh ◽  
T.E. Economou ◽  
A. L. Turkevich
Keyword(s):  
Room Temperature ◽  
Gamma Ray ◽  
Wide Bandgap ◽  
Hole Transport ◽  
Mercuric Iodide ◽  
Considerable Effort ◽  
X Ray ◽  
Transport Behavior ◽  
Gamma Ray Spectroscopy ◽  
Electron Transport Properties

Mercuric iodide (HgI2) with high atomic numbers of 80 and 53 for the components, and wide bandgap (2.1 eV) has been considered a potentially useful material for gamma ray spectroscopy for the last number of years. Considerable effort by numerous groups has been directed toward purification and growth of large single crystals of this material. Even with continuing improvement, however, the material is still characterized by good electron transport properties and only modest to poor hole transport behavior. Interesting results nevertheless have been reported in mid-range gamma ray spectroscopy using “up to millimeter thick sections of HgI2. One question always asked is: has the fundamental of lattice scattering etc. been reached in increasing hole transport behavior in this material? There is interesting speculation at this time that this may not be so.

Progress in Cdl-xZnxTe (CZT) Radiation Detectors

1993 ◽  
Vol 302 ◽  
Author(s):  
J. F. Butler ◽  
F. P. Doty ◽  
B. Apotovsky ◽  
S. J. Friesenhahn ◽  
C. Lingren
Keyword(s):  
Room Temperature ◽  
Ohmic Contacts ◽  
Gamma Ray ◽  
Surface Effect ◽  
Growth Parameters ◽  
Radiation Detectors ◽  
Imaging Data ◽  
Detector Arrays ◽  
X Ray ◽  
First Time

ABSTRACTResults of a program to improve the performance of Cd1-xZnxTe detectors by adjusting growth parameters to achieve low-strain, high purity low defect crystals, investigating surface effect phenomena and contacting methods, and establishing reproducible manufacturing methods are reviewed and discussed. Processing and fabrication methods were developed which are applicable throughout the composition range. Energy spectra for room temperature Cdl-xZnxTe detectors exhibit resolutions (FWHM) from 2.16 keV at 14 keV to 6.9 keV at 122 keV. An energy resolution of 910 eV at 5.9 keV was achieved at −25 C. Stable ohmic contacts and gamma ray detection for ZnTe are reported for the first time. Applications of Cdl-xZnxTe to nuclear medicine and X-ray fluorescence are discussed. New gamma ray imagers using Cd1-xZnxTe detector arrays are described, and imaging data for a 32 × 32 monolithic array of 1 mm2 elements on a 42mm × 42mm substrate are presented.

scholarly journals Synthesis and Characterisation of Thin Films of Bismuth Triiodide for Semiconductor Radiation Detectors

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Alka Garg ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Room Temperature ◽  
Active Material ◽  
Visible Region ◽  
Radiation Detectors ◽  
Radiation Absorption ◽  
X Rays ◽  
X Ray ◽  
Bismuth Iodide

Bismuth iodide is a potentially active material for room temperature radiation detector, as it is well reported in the literature that it has both wide energy band gap and high atomic absorption coefficient. Crystalline films of high atomic number and high radiation absorption coefficient can absorb the X-rays and convert them directly into electrical charges which can be read by imaging devices. Therefore, it was proposed to grow thin films of Bismuth iodide on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. The structural studies of the films were carried out using XRD and optical absorption measurement was carried out in the UV/VIS region using spectrophotometer. All Bismuth iodide films grown at room temperature are polycrystalline and show X-ray diffraction peaks at angles reported in research papers. The optical transmission spectra of BiI3 films show a high transmission of about 80% in visible region with a sharp fall near the fundamental absorption at 650 nm. Resistivity of the as-grown film was found to be around 1012 ohm-cm suitable value for X-ray detection application. Films were subjected to scanning electron microscopy to study the growth features of both as-grown and annealed films.

scholarly journals Characteristics of X-ray and gamma radiation detectors based on polycrystalline CdTe and CdZnTe films

2021 ◽  
pp. 81-86
Author(s):  
Sharifa Utamuradova ◽  
Sultanposha Muzafarova ◽  
Abdulla Abdugafurov ◽  
Kakhramon Fayzullaev ◽  
Elmira Naurzalieva ◽  
...  
Keyword(s):  
Room Temperature ◽  
Specific Resistance ◽  
Radiation Detectors ◽  
Columnar Structure ◽  
Nuclear Materials ◽  
X Ray ◽  
Molybdenum Substrate ◽  
Cdznte Detectors ◽  
And Control ◽  
Polycrystalline Semiconductor

Based on CdTe and CdZnTe detectors a number of promising devices were created, which found their application in metallurgy, in solving the problems of customs control and control of nuclear materials, as well as matrix detectors created for the manufacture of medical devices and devices for space research. Detectors, created on the basis of polycrystalline semiconductor CdTe and CdZnTe films with a columnar structure on a molybdenum substrate with a thickness d = 30150 μm, had a specific resistance p > 10^5 10^8 W-cm. The energy resolution of the CdTe and CdZnTe detectors at room temperature reached ~ 5 keV on the 59.6 keV 241Am line.

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.

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