Evaluation of neutron energy spectrum from accelerator neutron source using directional proportional counter and digital pulse processing

• Project/Area Number: 23560055
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied physics, general
• Research Institution: Osaka Prefecture University
• Principal Investigator: MIYAMARU HIROYUKI 大阪府立大学, 工学(系)研究科(研究院), 准教授 (80243187)
• Project Period (FY): 2011-04-28 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000); Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2011: ¥2,990,000 (Direct Cost: ¥2,300,000、Indirect Cost: ¥690,000)
• Keywords: 放射線計測 / 中性子 / 比例計数管 / エネルギースペクトル / デジタル処理

Outline of Final Research Achievements

A special cylindrical proportional neutron counter has been designed and developed to measure neutrons with wide energy range from a few eV to 1 MeV. A lot of thin plastic disks containing boron nitride powder were placed at 1 cm interval inside a counter to make an individual detection volume. Monte Carlo calculations repeated in a design cycle of the detector clarified that a neutron energy spectrum could be estimated by measuring the difference of neutron detection yield at each detection position.　Bayesian estimation was employed to evaluate a neutron energy spectrum from the counting rate at each position. Manipulation of a density gradient of boron for each disc changed the instrumental function and reproduced the energy distribution of neutrons around 1 MeV.
Combining with Bayesian estimation and the newly developed detector was found to be effective to evaluate neutrons in a wide energy area.

Research Products

• [Presentation] 加速器中性子源と位置敏感型比例計数管による熱外中性子検出器の開発 (2014)
  • Author(s): 宮丸 広幸
  • Organizer: 第55回放射線科学研究会
  • Place of Presentation: 住友クラブ（大阪府・大阪市）
  • Year and Date: 2014-10-17
• [Presentation] 位置敏感型比例計数管とデジタル処理による熱外中性子検出器の開発 ２ (2014)
  • Author(s): 宮丸広幸、村田勲、山本淳治
  • Organizer: 第75回応用物理学会秋季学術講演会
  • Place of Presentation: 北海道大学(北海道・札幌市）
  • Year and Date: 2014-09-17 – 2014-09-20
• [Presentation] 位置敏感型比例計数管とデジタル処理による熱外中性子検出器の開発 (2013)
  • Author(s): 宮丸広幸
  • Organizer: 第60回応用物理学会春季学術講演会
  • Place of Presentation: 神奈川工科大学