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Title: Field-portable high-resolution EDXRF analysis with HgI[sub 2]-detector-based instrumentation

Abstract

Energy dispersive x-ray fluorescence (EDXRF) analysis is well known for its efficient use of x-ray detector technology for simultaneous multielement determination. Low-intensity excitation, such as from a radioisotope source, can thus be employed and has enabled the design of many types of truly portable EDXRF instrumentation. Portable design, however, has not been without significant compromise in analytical performance because of the limited x-ray resolving power of prior detection methods, except by the use of a cryogenically operated detector. The developments we refer to stem from the use of a comparatively new x-ray detection device fabricated from mercuric iodide (HgI[sub 2]). For this detector, only a modest degree of cooling is required to achieve an energy resolution of > 300 eV. Two field-portable instrument designs of different hand-held measurement probe configurations are available that have applications for industrial quality assurance and environmental screening.

Authors:
; ;  [1]
  1. (TN Technologies, Inc., Round Rock, TX (United States))
Publication Date:
OSTI Identifier:
6454267
Report Number(s):
CONF-920919--
Journal ID: ISSN 0003-018X; CODEN: TANSAO
Resource Type:
Conference
Resource Relation:
Journal Name: Transactions of the American Nuclear Society; (United States); Journal Volume: 65:1; Conference: 2. topical meeting on industrial radiation and radioisotope measurement applications, Raleigh, NC (United States), 8-11 Sep 1992
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; SOILS; X-RAY FLUORESCENCE ANALYSIS; X-RAY FLUORESCENCE ANALYZERS; ACCURACY; MULTI-ELEMENT ANALYSIS; PORTABLE EQUIPMENT; QUALITY ASSURANCE; RESOLUTION; CHEMICAL ANALYSIS; EQUIPMENT; NONDESTRUCTIVE ANALYSIS; X-RAY EMISSION ANALYSIS 440103* -- Radiation Instrumentation-- Nuclear Spectroscopic Instrumentation

Citation Formats

Berry, P.F., Little, S.R., and Voots, G.R. Field-portable high-resolution EDXRF analysis with HgI[sub 2]-detector-based instrumentation. United States: N. p., 1992. Web.
Berry, P.F., Little, S.R., & Voots, G.R. Field-portable high-resolution EDXRF analysis with HgI[sub 2]-detector-based instrumentation. United States.
Berry, P.F., Little, S.R., and Voots, G.R. 1992. "Field-portable high-resolution EDXRF analysis with HgI[sub 2]-detector-based instrumentation". United States. doi:.
@article{osti_6454267,
title = {Field-portable high-resolution EDXRF analysis with HgI[sub 2]-detector-based instrumentation},
author = {Berry, P.F. and Little, S.R. and Voots, G.R.},
abstractNote = {Energy dispersive x-ray fluorescence (EDXRF) analysis is well known for its efficient use of x-ray detector technology for simultaneous multielement determination. Low-intensity excitation, such as from a radioisotope source, can thus be employed and has enabled the design of many types of truly portable EDXRF instrumentation. Portable design, however, has not been without significant compromise in analytical performance because of the limited x-ray resolving power of prior detection methods, except by the use of a cryogenically operated detector. The developments we refer to stem from the use of a comparatively new x-ray detection device fabricated from mercuric iodide (HgI[sub 2]). For this detector, only a modest degree of cooling is required to achieve an energy resolution of > 300 eV. Two field-portable instrument designs of different hand-held measurement probe configurations are available that have applications for industrial quality assurance and environmental screening.},
doi = {},
journal = {Transactions of the American Nuclear Society; (United States)},
number = ,
volume = 65:1,
place = {United States},
year = 1992,
month = 1
}

Conference:
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  • We have integrated a small, highly-reliable, electro-mechanical cryo-cooler with a high-resolution germanium detector for portable/field applications. The system weighs 6.8 kg and requires 40 watts of power to operate once the detector is cooled to its operating temperature. the detector is a 500 mm{sup 2} by 20-mm thick low-energy configuration that gives a full-width at half maximum (FWHM) energy resolution of 523 eV at 122 keV, when cooled with liquid nitrogen. The energy resolution of the detector, when cooled with the electro-mechanical cooler, is 570 eV at 122 keV. We have field tested this system in measurements of plutonium andmore » uranium for isotopic and enrichment information using the MGA and MGAU analysis programs without any noticeable effects on the results.« less
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  • The authors report on the development of a high resolution radiation imaging system which is capable of detecting and imaging the coincident gamma and X-ray emissions of the radioisotope iodine 125 ({sup 125}I). Iodine 125 is commonly available as a radioactive label to tag molecular biology probes. Iodine 125 decays via electron capture emitting a 35 keV gamma-ray with the prompt emission of several 27-32 keV X-rays. A coincidence condition can be set to detect the {sup 125}I decays thus reducing background radiation contribution to the image. They are testing the use of arrays of CsI(Na) crystal scintillators coupled tomore » position sensitive photomultiplier tubes for this application. Laboratory studies have thus far been done on mice using a prototype of the detector which is intended to be used to image gene expression in live mice to advance research in neurobiology.« less
  • We are developing high spatial resolution detector modules based on recently available NaI(T1) crystal scintillator arrays that are capable of detecting photons over a range of energies. We report on the testing of an array with individual element sizes of 1 mm x 1 mm arrays over the energy range of 28 keV to 511 keV. It is anticipated that these detector modules could be applied to small animal imaging utilizing single photon emitters such as iodine-125 (28-35 keV) and technetium-99m (140 keV); and also positron emitters such as fluorine-18. The performance of a 5 cm square array of NaI(T1)more » crystal scintillators in which each element is 1 mm x 1 mm x 5 mm in dimension was measured. The NaI(T1) array manufactured by Saint-Gobain was coupled to Hamamatsu position sensitive photomultiplier tubes and tested over a range of photon energies. In particular, we tested the NaI(T1) array with the Hamamatsu model R2487 position sensitive photomultiplier tube and the new Hamamatsu model 85 00 flat panel position sensitive photomultiplier tube. Though the NaI(T1) module performed best for the single photon emitters its use in positron emission tomography applications for small animal imaging could be possible even though resulting sensitivity is not ideal.« less
  • No abstract prepared.