Pulse filtering for thick mercuric iodide detectors
Mercuric iodide (HgI/sub 2/) is a semiconductor material of interest as a gamma-ray spectrometer due to its large band gap and high atomic number, properties which allow room temperature operation and provide high gamma-ray cross section. At EG and G Energy Measurements, Inc. (EG and G/EM), single crystals of mercuric iodide are grown by vapor sublimation and fabricated into detectors of 0.2-12.0 mm thickness. Thin detectors (< 1 mm) produce a good energy resolution (--1%-5% at 662 keV) and work well a x-ray detectors but have low gamma-ray efficiency. Detectors of 1 mm-1 cm thickness provide higher gamma ray efficiency but are limited by poor hole transport properties which degrade detector performance. When conventional pulse shaping is used, energy resolutions of 6%-12% and peak-to-valley ratio < 3:1 are typical for detectors of 1-5 mm thickness. Detectors of -- 1-cm thickness typically produce > 10% resolution and peak-to-valley ratios < 2:1. The authors have investigated a number of electronic pulse filtering techniques for thick mercuric iodide detectors and have achieved improved spectral response for detectors of 1-5 mm thickness and gamma ray energies up to 1.5 MeV. Conventional gaussian and gated integration filters were considered as well as more sophisticated filter combinations in order to develop methods of reducing charge measurement errors caused by poor hole collection. When using these techniques, energy resolutions of 3%-6% and peak-to-valley ratios of 5:1 are common. In this paper they discuss these approaches and present results with thick detectors.
- Research Organization:
- EG and G Energy Measurements, Inc., Santa Barbara Operations, 130 Robin Hill Road, Goleta, CA 93117
- OSTI ID:
- 6659989
- Report Number(s):
- CONF-861007-
- Journal Information:
- IEEE Trans. Nucl. Sci.; (United States), Journal Name: IEEE Trans. Nucl. Sci.; (United States) Vol. NS-34:1; ISSN IETNA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
440101* -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ATOMIC NUMBER
CRYSTALS
DETECTION
DIMENSIONS
ELECTRONIC CIRCUITS
ENERGY RESOLUTION
GAMMA DETECTION
GAMMA SPECTROMETERS
GRADED BAND GAPS
HALIDES
HALOGEN COMPOUNDS
HGI2 SEMICONDUCTOR DETECTORS
HOLES
IODIDES
IODINE COMPOUNDS
MEASURING INSTRUMENTS
MERCURY COMPOUNDS
MERCURY HALIDES
MERCURY IODIDES
MONOCRYSTALS
PULSE CIRCUITS
PULSE SHAPERS
PULSE TECHNIQUES
RADIATION DETECTION
RADIATION DETECTORS
RESOLUTION
SEMICONDUCTOR DETECTORS
SIGNAL CONDITIONERS
SPECTROMETERS
THICKNESS
TRAPPING