skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Performance of a large hyperpure germanium detector array for in-vivo detection of low-energy photon and x-ray emitters: analytical procedure and current capabilities

Abstract

The ORNL Whole Body Counter is one of the few in the country that is capable of assessment of body burdens of low-energy photon and x-ray emitters. This requires detectors and electronics specific for the task. Isotope identification and quantification capabilities are crucial at the facilities which deal with quantities of many radionuclides. The standard procedure for whole counting done at ORNL employs a 13.34 cm-dia. phoswich, a hyperpure germanium (HPGe) array consisting of six detectors totaling 80 cm/sup 2/, and a 23 cm by 23 cm NaI detector positioned under the subject's back. Isotope identification and quantification capabilities for detection of the actinides using the HPGe array are greatly improved over the phoswich system, making the HPGe detector an integral part of lung counting operations at ORNL. The HPGe array has been fully operational since May 1980. Since that time, calibrations have been performed with various sources, a calibration curve derived, and minimum significant measured activity (MSMA) and minimum detectable true activity (MDTA) for various radionuclides have been determined. The current analysis techniques are discussed, examples of MSMA and MDTA for various isotopes are given, and the derivation of a universal calibration curve for preliminary estimation of body burdenmore » is discussed using data acquired by the HPGe array.« less

Authors:
;
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (USA)
OSTI Identifier:
6007052
Report Number(s):
ORNL/TM-7925
ON: DE82000443; TRN: 81-017321
DOE Contract Number:
W-7405-ENG-26
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; HIGH-PURITY GE DETECTORS; CALIBRATION; WHOLE-BODY COUNTERS; BODY BURDEN; LUNGS; NAI DETECTORS; ORNL; PERSONNEL; PHOTON EMISSION; RADIOISOTOPES; X RADIATION; BODY; ELECTROMAGNETIC RADIATION; EMISSION; GE SEMICONDUCTOR DETECTORS; IONIZING RADIATIONS; ISOTOPES; MEASURING INSTRUMENTS; NATIONAL ORGANIZATIONS; ORGANS; RADIATION DETECTORS; RADIATIONS; RESPIRATORY SYSTEM; SCINTILLATION COUNTERS; SEMICONDUCTOR DETECTORS; SOLID SCINTILLATION DETECTORS; US AEC; US DOE; US ERDA; US ORGANIZATIONS; 400101* - Activation, Nuclear Reaction, Radiometric & Radiochemical Procedures; 560161 - Radionuclide Effects, Kinetics, & Toxicology- Man

Citation Formats

Berger, C.D., and Lane, B.H.. Performance of a large hyperpure germanium detector array for in-vivo detection of low-energy photon and x-ray emitters: analytical procedure and current capabilities. United States: N. p., 1981. Web. doi:10.2172/6007052.
Copy to clipboard
Berger, C.D., & Lane, B.H.. Performance of a large hyperpure germanium detector array for in-vivo detection of low-energy photon and x-ray emitters: analytical procedure and current capabilities. United States. doi:10.2172/6007052.
Copy to clipboard
Berger, C.D., and Lane, B.H.. Thu . "Performance of a large hyperpure germanium detector array for in-vivo detection of low-energy photon and x-ray emitters: analytical procedure and current capabilities". United States. doi:10.2172/6007052. https://www.osti.gov/servlets/purl/6007052.
Copy to clipboard
@article{osti_6007052,
title = {Performance of a large hyperpure germanium detector array for in-vivo detection of low-energy photon and x-ray emitters: analytical procedure and current capabilities},
author = {Berger, C.D. and Lane, B.H.},
abstractNote = {The ORNL Whole Body Counter is one of the few in the country that is capable of assessment of body burdens of low-energy photon and x-ray emitters. This requires detectors and electronics specific for the task. Isotope identification and quantification capabilities are crucial at the facilities which deal with quantities of many radionuclides. The standard procedure for whole counting done at ORNL employs a 13.34 cm-dia. phoswich, a hyperpure germanium (HPGe) array consisting of six detectors totaling 80 cm/sup 2/, and a 23 cm by 23 cm NaI detector positioned under the subject's back. Isotope identification and quantification capabilities for detection of the actinides using the HPGe array are greatly improved over the phoswich system, making the HPGe detector an integral part of lung counting operations at ORNL. The HPGe array has been fully operational since May 1980. Since that time, calibrations have been performed with various sources, a calibration curve derived, and minimum significant measured activity (MSMA) and minimum detectable true activity (MDTA) for various radionuclides have been determined. The current analysis techniques are discussed, examples of MSMA and MDTA for various isotopes are given, and the derivation of a universal calibration curve for preliminary estimation of body burden is discussed using data acquired by the HPGe array.},
doi = {10.2172/6007052},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Oct 01 00:00:00 EDT 1981},
month = {Thu Oct 01 00:00:00 EDT 1981}
}
Copy to clipboard
Technical Report:
View Technical Report (0.48 MB)
DOI:  10.2172/6007052
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

  • ;
    Calibration curves (chest wall thickness vs nCi/cpm) are developed for a large, hyperpure germanium detector array for measurement of lung burdens of /sup 238/Pu, /sup 239/Pu, and /sup 241/Am. Equations were derived using a 100% muscle-thorax model and models with varying concentrations of thoracic fat. Because of the superior energy resolution of the array, a means for estimating depth of deposition of these radionuclides was also developed. These results have been compiled and existing computer programs for data analysis have been adapted accordingly as part of the routine actinide lung counting program at ORNL. Although semiconductor detectors in general havemore » been shown to be well-suited for in-vivo actinide detection, design limitations associated with this detector array were noted as part of this study. Modifications to overcome those limitations will play a large part in long-range plans for development of the ORNL Whole Body Counter Facility.« less

  • ;
    For calibration of the array for internally deposited /sup 238/Pu, /sup 239/Pu, and /sup 241/Am, a tissue-equivalent anthropomorphic phantom, was used for efficiency determinations at the ORNL facility. This phantom consists of a tissue-equivalent torso into which is imbedded an adult male skeleton, interchangeable organs containing a homogeneous distribution of various radionuclides, and two sets of chest overlay plates for simulation of progressively thicker tissue over the chest, as well as differing thoracic fat contents. (PSB)

  • ; ; - Health Physics
    The in-vivo monitoring of low energy x- and gamma-ray emitters gained importance with the increasing use of these radionuclides in nuclear medicine and nuclear energy production. The main problems encountered are the lack of accuracy in the measurement and the high detection limits obtained with the classical techniques. The best technique available today is the array of planar germanium detectors. The purpose of this paper is to analyze specific problems in the assessment of low energy photon emitters in the body and to describe applications of room-temperature diodes (silicon and CdZnTe) using a new technique involving a portable jacket. Inmore » certain cases, the device can be used outside a shielded room, making possible an immediate long counting, reducing the psychological stress, and optimizing the medical treatment and the intervention. By considering the attenuation effect, this work shows that an optimized volume of the diodes reduces the detection limits of the counting. The developed methodology offers new possibilities in the assessment of radioactive deposition in the body and in the long term follow-up of the metabolism of radionuclides in small quantities.« less

  • ; ;
    The problems associated with the in vivo detection and measurement of actinides in the human lung are discussed together with various measurement systems currently in use. In particular, the methods and calibration procedures employed at the Lawrence Livermore Laboratory, namely, the use of twin Phoswich detectors and a new, more realistic, tissue-equivalent phantom, are described. Methods for the measurement of chest-wall thickness, fat content, and normal human background counts are also discussed. Detection-efficiency values and minimum detectable activity estimates are given for three common actinides, /sup 238/Pu, /sup 239/Pu, and /sup 241/Am.

  • ; ;