Pulse filtering for thick mercuric iodide detectors

Conference · Sun Feb 01 00:00:00 EST 1987 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:6659989

Gerrish, V M; Williams, D J; Beyerle, A G

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), Vol. NS-34:1; Conference: Nuclear science and nuclear power systems symposium, Washington, DC, USA, 29 Oct 1986
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
42 ENGINEERING
GAMMA DETECTION
HGI2 SEMICONDUCTOR DETECTORS
PULSE SHAPERS
ATOMIC NUMBER
ENERGY RESOLUTION
GAMMA SPECTROMETERS
GRADED BAND GAPS
HOLES
MERCURY IODIDES
MONOCRYSTALS
PULSE TECHNIQUES
THICKNESS
TRAPPING
CRYSTALS
DETECTION
DIMENSIONS
ELECTRONIC CIRCUITS
HALIDES
HALOGEN COMPOUNDS
IODIDES
IODINE COMPOUNDS
MEASURING INSTRUMENTS
MERCURY COMPOUNDS
MERCURY HALIDES
PULSE CIRCUITS
RADIATION DETECTION
RADIATION DETECTORS
RESOLUTION
SEMICONDUCTOR DETECTORS
SIGNAL CONDITIONERS
SPECTROMETERS
440101* - Radiation Instrumentation- General Detectors or Monitors &amp; Radiometric Instruments
420800 - Engineering- Electronic Circuits &amp; Devices- (-1989)