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Multisample thermoluminescence reading
Nuclear Instruments and Methods 175 (1980) 96-97 © North-Holland Publishing Company
MULTISAMPLE THERMOLUMINESCENCE READING J. GASIOT, M. CASTAGNE, J.P. FILLARD, P. BRAUNLICH * and G. PORTAL ** C.E.E.S. IL.A. 21-C.N.R.S.), U.S.T.L., 34060 Montpellier, France
A new system is described which is designed to simultaneously measure the thermoluminescence of 12 or more samples during one single temperature scan. It utilizes a vidicon tube which is coupled to the sample array by optical fibers.
Despite much work on thermoluminescence (TSL) applications many important problems remain to be solved. This is true even for TSL dosimetry, a well documented success story [1]. In it and in all other applications known to data, the TSL experiments are adapted to solve the particular problems associated with, e.g., dosimetry in environmental protection [2], archaeological dating, art authentification [3], and radiotherapy, goelogy, and uranium prospecting [4]. In all applications the thermoluminescence of the sample is recorded on a one by one basis. Automated equipment has been developed to achieve this, e.g. in personnel dosimetry, quickly and inexpensively [5]. Yet distinct improvements are obvious for each particular application. Advantages offered by (1) fast heating [6], (2) optical fiber coupling, (3) multisample detection (through vidicon tubes, for example [7]), (4) microprocessor control of the experiment, and data processing are examples. In this paper we describe a new system designed to simultaneously measure, during a single temperature scan, the thermoluminescence of 12 samples (fig. 1). The detector is a sensitive array of 500 single photon counters which are part of an O.M.A. (P.A.R.) system with a intensified vidicon tube (I.S.I.T.). The sample matrix is efficiently optically coupled to and thermally separated from this detector array by optical fibers or a fiber bundle face plate. Computer processing permits either to rapidly evaluate the thermoluminescence data of each individual
sample or a thermoluminescent image of the sample matrix may be obtained to assess the spatial distribution of the instantaneous or integrated thermoluminescent yield. The experimental set-up presented here is only a first simple attempt and can obviously be improved. The number of samples analysed could be as large as 104 using new vidicon tubes or other systems in conjunction with an ordered optical fiber bundle. Presently, we are only interested in the feasability and optical performance of this kind of system and so, only preliminary results are presented. We have studied some ZnS : Cu, LiF and CaSO4 powders. Curves ol-.ained for the first material are presented in fig. 2. Most of the information available in such a system is recorded on magnetic tape. Here, only X - - Y plots are shown. Potential areas of applications of such systems are TSL imaging, spectrum analysis, fast TSL processing through many-sample analysis, and the possibility of accurately calibrating the sensitivity of TSL dose measurement by simulta-
Vidic°ntubel multich.... I Optical~'~ 1/ aC)nii;~lr Pa fibers_t I[1 ' 1
Microprocessor L Magnetic tape
Heater
X-Y
* On leave from Washington State University, Pullman, WA 99164, U.S.A. ** C.E.A., B.P. 6, 92260 Fontenay-aux-Roses, France.
Fig. 1. Schematic arrangement of multisample TSL reading. 96
J. Gasiot et al. / Multisample TL reading
References
TTSL
1Sample number
4
5
6
7
8
9
10
11
12
i
Channel number 100
97
20(3
300
400
500
Fig. 2. X Y plots of TSL on ZnS : Cu powders integrated dose for each sample as obtained on the detector array of a vidicon, during one single temperature scan.
neously evaluating unknown as well as test samples during one temperature scan.
[1]Topics in applied physics, no. 37 (Springer-Verlag, Berlin). [2] G. Portal, Thesis (Toulouse, 1978). [3] M.J. Aikcn, Phys. Reports 406 (1978) 278. [4] J.M. Charlet, Ch. Dupuis and Y. Quinif, 5e rdunion annuelle des Sciences de la Terre, Rennes (1977). [5] G. Portal, R. Pringent, Ph. Blanchard and R. Chenault, Proc. 5th Int. Conf. on Luminescence dosimetry, Sao Paulo, Brazil (1977). [6] M. Kawanishi and H. Donishi, Proc. 5th Int. Syrup. on Exoelectron emission and dosimetry, Zuivkov (1976). [7] J.P. Fillard, M. de Murcia, J. Gasiot and S. Chor, J. Phys. E8 (1975) 994. [8] M. Castagne, J. Gasiot and J.P. Fillard, J. Plays. E l l (1978) 345.
VI. INSTRUMENTATION
MULTISAMPLE THERMOLUMINESCENCE READING J. GASIOT, M. CASTAGNE, J.P. FILLARD, P. BRAUNLICH * and G. PORTAL ** C.E.E.S. IL.A. 21-C.N.R.S.), U.S.T.L., 34060 Montpellier, France
A new system is described which is designed to simultaneously measure the thermoluminescence of 12 or more samples during one single temperature scan. It utilizes a vidicon tube which is coupled to the sample array by optical fibers.
Despite much work on thermoluminescence (TSL) applications many important problems remain to be solved. This is true even for TSL dosimetry, a well documented success story [1]. In it and in all other applications known to data, the TSL experiments are adapted to solve the particular problems associated with, e.g., dosimetry in environmental protection [2], archaeological dating, art authentification [3], and radiotherapy, goelogy, and uranium prospecting [4]. In all applications the thermoluminescence of the sample is recorded on a one by one basis. Automated equipment has been developed to achieve this, e.g. in personnel dosimetry, quickly and inexpensively [5]. Yet distinct improvements are obvious for each particular application. Advantages offered by (1) fast heating [6], (2) optical fiber coupling, (3) multisample detection (through vidicon tubes, for example [7]), (4) microprocessor control of the experiment, and data processing are examples. In this paper we describe a new system designed to simultaneously measure, during a single temperature scan, the thermoluminescence of 12 samples (fig. 1). The detector is a sensitive array of 500 single photon counters which are part of an O.M.A. (P.A.R.) system with a intensified vidicon tube (I.S.I.T.). The sample matrix is efficiently optically coupled to and thermally separated from this detector array by optical fibers or a fiber bundle face plate. Computer processing permits either to rapidly evaluate the thermoluminescence data of each individual
sample or a thermoluminescent image of the sample matrix may be obtained to assess the spatial distribution of the instantaneous or integrated thermoluminescent yield. The experimental set-up presented here is only a first simple attempt and can obviously be improved. The number of samples analysed could be as large as 104 using new vidicon tubes or other systems in conjunction with an ordered optical fiber bundle. Presently, we are only interested in the feasability and optical performance of this kind of system and so, only preliminary results are presented. We have studied some ZnS : Cu, LiF and CaSO4 powders. Curves ol-.ained for the first material are presented in fig. 2. Most of the information available in such a system is recorded on magnetic tape. Here, only X - - Y plots are shown. Potential areas of applications of such systems are TSL imaging, spectrum analysis, fast TSL processing through many-sample analysis, and the possibility of accurately calibrating the sensitivity of TSL dose measurement by simulta-
Vidic°ntubel multich.... I Optical~'~ 1/ aC)nii;~lr Pa fibers_t I[1 ' 1
Microprocessor L Magnetic tape
Heater
X-Y
* On leave from Washington State University, Pullman, WA 99164, U.S.A. ** C.E.A., B.P. 6, 92260 Fontenay-aux-Roses, France.
Fig. 1. Schematic arrangement of multisample TSL reading. 96
J. Gasiot et al. / Multisample TL reading
References
TTSL
1Sample number
4
5
6
7
8
9
10
11
12
i
Channel number 100
97
20(3
300
400
500
Fig. 2. X Y plots of TSL on ZnS : Cu powders integrated dose for each sample as obtained on the detector array of a vidicon, during one single temperature scan.
neously evaluating unknown as well as test samples during one temperature scan.
[1]Topics in applied physics, no. 37 (Springer-Verlag, Berlin). [2] G. Portal, Thesis (Toulouse, 1978). [3] M.J. Aikcn, Phys. Reports 406 (1978) 278. [4] J.M. Charlet, Ch. Dupuis and Y. Quinif, 5e rdunion annuelle des Sciences de la Terre, Rennes (1977). [5] G. Portal, R. Pringent, Ph. Blanchard and R. Chenault, Proc. 5th Int. Conf. on Luminescence dosimetry, Sao Paulo, Brazil (1977). [6] M. Kawanishi and H. Donishi, Proc. 5th Int. Syrup. on Exoelectron emission and dosimetry, Zuivkov (1976). [7] J.P. Fillard, M. de Murcia, J. Gasiot and S. Chor, J. Phys. E8 (1975) 994. [8] M. Castagne, J. Gasiot and J.P. Fillard, J. Plays. E l l (1978) 345.
VI. INSTRUMENTATION