| アイテムタイプ |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2026-02-17 |
| タイトル |
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タイトル |
Monte Carlo simulation to optimize measurement geometry of continuous air monitor with Si semiconductor detector |
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言語 |
en |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
journal article |
| 著者 |
Yuki Tamakuma
Hiroki Hashimoto
Manaya Taoka
Ryohei Yamada
Kazuki Iwaoka
Yasutaka Omori
Masahiro Hosoda
Shinji Tokonami
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| 抄録 |
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内容記述タイプ |
Abstract |
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内容記述 |
One of the challenges in real-time monitoring of airborne alpha-emitting radionuclides using Continuous Air Monitors (CAMs) is to discriminate alpha particles emitted by artificial radionuclides from those emitted by natural radionuclides, as the alpha energy spectrum is easily degraded due to its high stopping power. Although the measurement geometry significantly affects the alpha energy spectrum, there are no reports that have investigated the optimized geometry. This study conducted a Monte Carlo simulation to optimize the measurement geometry of the CAMs. The CAM was modelled using a radiation transport simulation code, and the counting efficiencies for 218Po and 239Pu and the overlapping ratio were simulated. The Minimum Detectable Concentration (MDC) of 239Pu was then estimated as an indicator to optimize the geometry. Although a constant counting efficiency is generally used for the same geometry regardless of the alpha energy, the counting efficiency differed up to ∼0.04 by the alpha energy depending on the measurement geometry. The overlapping ratio for a 50-mm diameter detector ranged from 0.22 to 0.35, while those for a 25-mm diameter detector was below 0.25. This discrepancy is because of the incident angle distribution biased towards large angles. The lowest MDC was estimated to be ∼3 Bq m−3 at 20 L min−1 under 25 Bq m−3 of 218Po. The MDC was low for small filter diameters and Filter-to-Detector Distances (FDDs) under most of the simulated conditions. The results indicate that a shorter filter diameter and FDD would be preferable for alpha spectrometry under normal air pressure. |
| 書誌情報 |
Radiation Physics and Chemistry
巻 241,
p. 113507,
発行日 2025-12
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| DOI |
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識別子タイプ |
DOI |
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関連識別子 |
10.1016/j.radphyschem.2025.113507 |
