Characterization of stilbene and EJ-276 scintillators coupled with a large area SiPM array for a fast neutron dose rate detector
| Autor: | N. Dinar, L. Gallego Manzano, Marco Silari, F. Ferrulli, M. Labalme |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
Nuclear and High Energy Physics Survey meter 010308 nuclear & particles physics Analytical chemistry Scintillator Atmospheric temperature range 01 natural sciences 030218 nuclear medicine & medical imaging 03 medical and health sciences 0302 clinical medicine Silicon photomultiplier 0103 physical sciences Neutron detection Neutron source Figure of merit Neutron Instrumentation |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 1010:165566 |
| ISSN: | 0168-9002 |
| Popis: | A 1-inch stilbene and EJ-276 (plastic) organic scintillators were characterized in view of their use in a portable survey meter for fast neutron detection and dose rate measurements in radiation protection. They were coupled with a large area Silicon Photomultiplier (SiPM) array and characterized in terms of neutron/ γ –ray (n/ γ ) discrimination capability, count rate linearity, count rate saturation effects, temperature stability and neutron detection efficiency. A Pile-Up Rejection (PUR) algorithm was developed and tested to increase their count rate linearity with increasing dose rate. Results show that the stilbene exhibits better performance compared to the plastic in terms of: Pulse Shape Discrimination (PSD) with a Figure Of Merit (FOM) of 1.5 vs. 1.1, energy resolution (15% vs 20% at 662 keV) and fast neutron efficiency (12% vs. 9% with an AmBe source). For both scintillators, the dose rate response is linear up to 1 mSv/h with a 137Cs γ -ray source. With a neutron source , the response is linear, and the FOM is almost constant for dose rates up to 1.5 mSv/h. The PUR reduces the false neutron events by one order of magnitude when the detectors are irradiated with a γ -ray source up to 10 mSv/h, and it correctly works when irradiated with an AmBe source at 1.5 mSv/h together with a 137Cs source up to 60 μ Sv/h. The proposed PUR algorithm is promising but needs to be tested with a higher intensity mixed n/ γ field. The temperature stability of both detectors was also studied in the temperature range from −10 °C to ＋40 °C. The light yield increases by around 25% for both detectors when reducing the temperature. The variation of the neutron count rate is around 10% in the same temperature range. This work provides a complete overview of the performance of these detectors and a coherent comparison between the two types of scintillators with the same experimental setup. |
| Databáze: | OpenAIRE |
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