Application of CdTe (CdZnTe) detectors for radioactive waste characterization

The radiation detectors based on wide-zone semiconductor CdTe (CdZnTe) monocrystals have promising advantages for their application in investigation (characterization) of radioactive waste. Among these advantages there are the wide range of photons flux and energy, high registration efficiency and s...

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Опубліковано в: :Вопросы атомной науки и техники
Дата:2002
Автори: Dovbnya, N.A., Karasyov, S.P., Kutny, V.E., Rybka, A.V., Shlyakhov, I.N., Uvarov, V.L.
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Мова:Англійська
Опубліковано: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2002
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Назва журналу:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Цитувати:Application of CdTe (CdZnTe) detectors for radioactive waste characterization / N.A. Dovbnya, S.P. Karasyov, V.E. Kutny, A.V. Rybka, I.N. Shlyakhov, V.L. Uvarov // Вопросы атомной науки и техники. — 2002. — № 2. — С. 55-57. — Бібліогр.: 3 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Dovbnya, N.A.
Karasyov, S.P.
Kutny, V.E.
Rybka, A.V.
Shlyakhov, I.N.
Uvarov, V.L.
author_facet Dovbnya, N.A.
Karasyov, S.P.
Kutny, V.E.
Rybka, A.V.
Shlyakhov, I.N.
Uvarov, V.L.
citation_txt Application of CdTe (CdZnTe) detectors for radioactive waste characterization / N.A. Dovbnya, S.P. Karasyov, V.E. Kutny, A.V. Rybka, I.N. Shlyakhov, V.L. Uvarov // Вопросы атомной науки и техники. — 2002. — № 2. — С. 55-57. — Бібліогр.: 3 назв. — англ.
collection DSpace DC
container_title Вопросы атомной науки и техники
description The radiation detectors based on wide-zone semiconductor CdTe (CdZnTe) monocrystals have promising advantages for their application in investigation (characterization) of radioactive waste. Among these advantages there are the wide range of photons flux and energy, high registration efficiency and satisfactory energy resolution without deep cooling of the detector. This report discusses the obtained data concerning radiation stability of detectors, influence of different conditions (filters, collimators, registration channel fill etc.) on their energy resolution in spectrometric regime, as well as a dependence of radionuclide identification accuracy on detector size.
first_indexed 2025-12-07T13:11:48Z
format Article
fulltext A P P L I C A T I O N O F T H E N U C L E A R M E T H O D S APPLICATION OF CdTe (CdZnTe) DETECTORS FOR RADIOACTIVE WASTE CHARACTERIZATION* N.A. Dovbnya, S.P. Karasyov, V.E. Kutny, A.V. Rybka, I.N. Shlyakhov, V.L. Uvarov National Scientific Centre “Kharkov Institute of Physics and Technology”, Kharkov, Ukraine e-mail: karasyov@kipt.kharkov.ua The radiation detectors based on wide-zone semiconductor CdTe (CdZnTe) monocrystals have promising advantages for their application in investigation (characterization) of radioactive waste. Among these advantages there are the wide range of photons flux and energy, high registration efficiency and satisfactory energy resolution without deep cooling of the detector. This report discusses the obtained data concerning radiation stability of detectors, influence of different conditions (filters, collimators, registration channel fill etc.) on their energy resolution in spectrometric regime, as well as a dependence of radionuclide identification accuracy on detector size. PACS 07.85.-m, 07.88.+y, 81.70.Jb 1. INTRODUCTION The counting and spectrometric measurements are widely used for determination of a partial activity of radioactive waste. Application of spectrometers based on Ge(Li) detectors, having high sensitivity and energy resolution, allows to solve the problems of analysis of the count samples (see, for example, [1]). However, these problems are solved mainly under conditions of laboratories and measurement stands. The use of such detectors for a remote monitoring is impeded or impossible at all because of the necessity of their cooling up to fluid nitrogen temperature. Besides, Ge(Li) detector to be placed in a cryostat has the considerable dimensions. Therefore a development of spectrometers on a basis of CdTe (CdZnTe) monocrystal having enough resolution and not requiring severe cooling is an urgent problem of the field gamma- spectrometry. The purpose of this work is the improvement of energy resolution of a spectrometer using CdZnTe detector by means of a noise characteristics improvement of the preamplifier and magnification as much as possible of permissible statistical fill of the spectrometer circuit. 2. DESIGN OF SPECTROMETER Spectrometer is executed structurally as a block of detection (it consists of CdZnTe detector, preamplifier and feed filter) supplied with the thin (20 µm) Ве window and block of the amplifier - shaper. The basic problem faced during development of the spectrometer was the improvement of its energy resolution in a given range of the gammas energy. A resolution of spectrometer with a semiconductor detector is determined by a number of parameters. First of all it depends on a collection efficiency of charge carriers generated by gamma radiation in the detector volume, on a performance of detector material (the lifetime, mobility of charge carriers), its homogeneity, and on a voltage applied to the detector. Other factor giving the essential contribution to quantity of the energy resolution, is the electric noise of detector- preamplifier system connected with fluctuations of detector current. The measuring circuit of the spectrometer is executed using Analog Devices elements. The block diagram of the spectrometer is represented in Fig. 1. 2 3 4 5 6 71 Fig. 1. Block diagram of counter - spectrometer (CS) with CdZnTe detector: 1 - detector; 2 - preamplifier; 3 - high-voltage feed; 4 - pulse shaper- amplifier; 5 – stabilizer of datum level; 6 - analogue- digital converter (ADC); 7 - IBM-PC A signal from CdZnTe detector output acts on the preamplifier. From the latter a pulse acts on the shaper amplifier with a stabilizer of datum level and a rejecter of superimpositions. Then a signal is digitised in the 12 bits ADC. The detector is connected directly to gate of first stage transistor of the preamplifier for elimination of noise of the input capacitor. A dependence of the CS energy resolution on detector voltage Ud demonstrates the spectrums, which are given in Fig. 2. A collimating of gammas flux improves the energy resolution of spectrometer (see Fig. 3). Its calibration was carried out with use of standard Am-241 source. * Work is supported by STCU under contract № 2185 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. 2002, № 2. Series: Nuclear Physics Investigations (40), p. 55-57. 55 2. OPERATION OF SPECTROMETER UNDER MAJOR FILL Tacking into account the CS operation with high- active samples its energy resolution dependence on input pulse frequency is of a great importance. The spectrums of high-active 99Mo sample (exposition dose rate 100 mR/s) measured with CdZnTe detector are submitted in Fig. 4. 0 100 200 300 400 500 N channel 0 200 400 600 800 1000 N count a) 0 100 200 300 400 500 N channel 0 200 400 600 800 N count b) 0 100 200 300 400 500 N channel 0 200 400 600 800 N count c) The CS energy resolution was measured along the line Еγ=140 keV (Tc-99m - daughter nucleus of the Мо- 99 isotope). It is visible from spectrums obtained that at the fill less than 104s-1 the resolution does not change practically. At the fill more than 2*104s-1 the resolution is worsened, that can be explained by an overload of the spectrometer (preamplifier and amplifier - shaper). 0 200 400 N channel 0 200 400 600 N count d) 0 200 400 600 N channel 0 400 800 1200 N count e) Fig. 2. a) - Ud=50V; b) - Ud=75V; c) - Ud=100V; d) - Ud=150V; e) - Ud=200V The fill of the CS was varied by change of sample- detector distance. Besides the various filter materials were used (Fig. 5,6). The fill was checked using the software of pulse analyzer. CONCLUSIONS As a result of carried out examinations the small- sized not cooled counter - spectrometer with the following specification is designed: CdZnTe monocrystal size, mm − 6х6х1; rated detector temperature t, °С − 25; detector noise at t, кeV − no more than 1.6; maximum fill of spectrometer nmax, с-1 − 2*104 ; resolution for energy of gammas Еγ=59.6 кeV (Am-241) at nmax,% − no more than 10; detection block size, mm − 30х40х35; maximum detection block- amplifier-shaperdistance, m − not less than 50. Last two parameters provide a possibility of detector operation with the remote controllable manipulators for analysis of the samples in hard-to-reach places or under high-level irradiation. 56 0 200 400 N channel 0 200 400 600 N count a) 0 200 400 600 N channel 0 200 400 600 N count b) Fig. 3. The same, that in Fig. 2 with 1.5 mm Fe collimator 0 400 800 1200 1600 N channel 0 200 400 600 N count Fig. 4. Spectrum of 99Мо sample (Cu filter of 2 mm thick) 0 400 800 1200 1600 N channel 0 100 200 300 400 N count Fig. 5. The same, that in Fig.4 with Al filter of 1mm thick and 1.5 mm Fe collimator 0 400 800 1200 1600 N channel 0 400 800 1200 N count Fig. 6. The same, that in Fig. 4, with Cu filter of 0.5 mm thick REFERENCES 1. B.N. Belayev, V.A. Babichev, E.A. Gromov et al. Experimental examination of the spent RBMC-1000 fuel and use of radioactivity correlations in analysis of the samples selected from Chernobyl zone. Radiochemistry // 1991, № 4, p. 149-159 2. V.I. Ivanov, V.V. Kondrashov et al. CdTe gamma-spectrometer with system of pulses-shape discrimination // .PTE, 1999, № 3, p. 47-53 3. L.T. Jones and P.B. Woollam. Resolution Improvement in CdTe Gamma Detectors Using Pulse- Shape Discrimination. // NIM. 1975, v. 124, p. 591-595 57 N.A. Dovbnya, S.P. Karasyov, V.E. Kutny, A.V. Rybka, I.N. Shlyakhov, V.L. Uvarov 1. INTRODUCTION CONCLUSIONS REFERENCES
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1562-6016
language English
last_indexed 2025-12-07T13:11:48Z
publishDate 2002
publisher Національний науковий центр «Харківський фізико-технічний інститут» НАН України
record_format dspace
spelling Dovbnya, N.A.
Karasyov, S.P.
Kutny, V.E.
Rybka, A.V.
Shlyakhov, I.N.
Uvarov, V.L.
2015-04-12T06:14:46Z
2015-04-12T06:14:46Z
2002
Application of CdTe (CdZnTe) detectors for radioactive waste characterization / N.A. Dovbnya, S.P. Karasyov, V.E. Kutny, A.V. Rybka, I.N. Shlyakhov, V.L. Uvarov // Вопросы атомной науки и техники. — 2002. — № 2. — С. 55-57. — Бібліогр.: 3 назв. — англ.
1562-6016
PACS 07.85.-m, 07.88.+y, 81.70.Jb
https://nasplib.isofts.kiev.ua/handle/123456789/80114
The radiation detectors based on wide-zone semiconductor CdTe (CdZnTe) monocrystals have promising advantages for their application in investigation (characterization) of radioactive waste. Among these advantages there are the wide range of photons flux and energy, high registration efficiency and satisfactory energy resolution without deep cooling of the detector. This report discusses the obtained data concerning radiation stability of detectors, influence of different conditions (filters, collimators, registration channel fill etc.) on their energy resolution in spectrometric regime, as well as a dependence of radionuclide identification accuracy on detector size.
* Work is supported by STCU under contract № 2185
en
Національний науковий центр «Харківський фізико-технічний інститут» НАН України
Вопросы атомной науки и техники
Application of the nuclear methods
Application of CdTe (CdZnTe) detectors for radioactive waste characterization
Использование CdTe(CdZnTe)-детекторов для характеризации радиоактивных отходов
Article
published earlier
spellingShingle Application of CdTe (CdZnTe) detectors for radioactive waste characterization
Dovbnya, N.A.
Karasyov, S.P.
Kutny, V.E.
Rybka, A.V.
Shlyakhov, I.N.
Uvarov, V.L.
Application of the nuclear methods
title Application of CdTe (CdZnTe) detectors for radioactive waste characterization
title_alt Использование CdTe(CdZnTe)-детекторов для характеризации радиоактивных отходов
title_full Application of CdTe (CdZnTe) detectors for radioactive waste characterization
title_fullStr Application of CdTe (CdZnTe) detectors for radioactive waste characterization
title_full_unstemmed Application of CdTe (CdZnTe) detectors for radioactive waste characterization
title_short Application of CdTe (CdZnTe) detectors for radioactive waste characterization
title_sort application of cdte (cdznte) detectors for radioactive waste characterization
topic Application of the nuclear methods
topic_facet Application of the nuclear methods
url https://nasplib.isofts.kiev.ua/handle/123456789/80114
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