MTS-6 detectors calibration by using 239Pu-Be neutron source
Background: Thermoluminescent detectors, type MTS-6, containing isotope 6Li (lithium) are sensitive in the range of thermal neutron energy; the 239Pu-Be (plutonium-and-beryllium) source emits neutrons in the energy range from 1 to 11 MeV. These seemingly contradictory elements may be combined by usi...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Nofer Institute of Occupational Medicine
2017-12-01
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| Series: | Medycyna Pracy |
| Subjects: | |
| Online Access: | http://medpr.imp.lodz.pl/MTS-6-detectors-calibration-by-using-239-Pu-Be-neutron-source,76454,0,1.html |
| Summary: | Background: Thermoluminescent detectors, type MTS-6, containing isotope 6Li (lithium) are sensitive in the range of thermal neutron energy; the 239Pu-Be (plutonium-and-beryllium) source emits neutrons in the energy range from 1 to 11 MeV. These seemingly contradictory elements may be combined by using the paraffin moderator, a determined density of thermal neutrons in the paraffin block and a conversion coefficient neutron flux to kerma, not forgetting the simultaneous registration of the photon radiation inseparable from the companion neutron radiation. The main aim of this work is to present the idea of calibration of thermoluminescent detectors that consist of a 6Li isotope, by using 239Pu-Be neutron radiation source. Material and Methods: In this work, MTS-6 and MTS-7 thermoluminescent detectors and a plutonium-and-beryllium (239Pu-Be) neutron source were used. Paraffin wax fills the block, acting as a moderator. The calibration idea was based on the determination of dose equivalent rate based on the average kerma rate calculated taking into account the empirically determined function describing the density of thermal neutron flux in the paraffin block and a conversion coefficient neutron flux to kerma. Results: The calculated value of the thermal neutron flux density was 1817.5 neutrons/cm2/s and the average value of kerma rate determined on this basis amounted to 244 μGy/h, and the dose equivalent rate 610 μSv/h. The calculated value allowed for the assessment of the length of time of exposure of the detectors directly in the paraffin block. Conclusions: The calibration coefficient for the used batch of detectors is (6.80±0.42)×10–7 Sv/impulse. Med Pr 2017;68(6):705–710 |
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| ISSN: | 0465-5893 2353-1339 |