Development of a Low Energy Proton Detector Using a Ruby Scintillator

使用红宝石闪烁体开发低能质子探测器

• 批准号: 11680513
• 负责人: NIHEI Hitoshi
• 金额: $ 0.45万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11680513/
• 关键词: NEUTRON; ULTRA COLD NEUTRON (UCN); LIFE TIME OF NEUTRON; MAGNETIC BOTTLE; PROTON DETECTOR; LOW ENERGY; RUBY SCITILLATOR; 低エネルギープロトン; 中性子崩壊; シンチレーター

A magnetic bottle of ultracold neutrons (UCN) based on a multiple cusp configuration using permanent magnets has been proposed by N. Inoue, H. Nihei and N. Akiyama. Confinement of UCN can be confirmed by detecting protons produced by the decay of UCN in the bottle. The protons are collected efficiently and detected by a proton detector which is installed on the ceiling of the bottle and biased at about -50 〜 -100kV. It is necessary to develop a low-energy proton detector system insensitive to neutron and γ-ray, since the detector is used near an atomic reactor.The detector used is a ruby scintillator containing chromium (Al_2O_3(Cr_2O_3)). In this scintillator the (n, p) reaction rate is very small, and the effect of γ-ray also can be made very small since the scintillator can be laminated. The thickness of the scintillator is 0.02 mm. The results obtained in this research are described. (1) Alpha-particles (5.5 MeV) emitted from ^<241>Am source and protons (0.2 〜 1.0 Mev) accelerated by a Van-deGraph accelerator were irradiated to the scintillator installed on the surface of a low noise type photomultiplier. When a single charged prticle has been irradiated, the output signal from the photomultiplier consists of many isolated signals. The gross decay time of the signal has been about 2.5 ms. (2) The luminescence spectrum having some different wavelengths was observed by a spectrometer. This result is consistent with the data reported elsewhere. (3) The sensitivity of the detector system to neutron and γ-ray was tested in the reactor room of KUR (Kyoto Univ. Reactor). It has been confirmed that the detector system is almost insensitive to neutron and γ-ray. (4) It is given as a conclusion that by combining the characteristics obtained by the above mentioned experimental results, it is possible to make a low-energy proton detector with high S/N ratios.

N. Inoue、H. Nihei 和 N. Akiyama 提出了一种基于使用永磁体的多尖点配置的超冷中子 (UCN) 磁瓶。可以通过检测瓶中 UCN 衰变产生的质子来确认 UCN 的限制。质子被有效收集并由安装在瓶子顶部并偏置约-50〜-100kV的质子检测器检测。由于该探测器在原子反应堆附近使用，因此有必要开发一种对中子和γ射线不敏感的低能质子探测器系统。所用探测器是含铬(Al_2O_3(Cr_2O_3))的红宝石闪烁体。在该闪烁体中，(n，p)反应速度非常小，并且由于闪烁体可以被层压，所以γ射线的影响也可以变得非常小。闪烁体的厚度为0.02毫米。描述了本研究中获得的结果。 (1)将从^ 241 Am源发射的α粒子(5.5MeV)和由Van-deGraph加速器加速的质子(0.2～1.0Mev)照射到安装在低噪声型光电倍增管表面上的闪烁体。当单个带电粒子受到照射时，光电倍增管的输出信号由许多隔离信号组成。信号的总衰减时间约为 2.5 毫秒。 (2)通过分光计观察具有一些不同波长的发光光谱。这一结果与其他地方报告的数据一致。 (3)在KUR(京都大学反应堆)反应堆室中测试了探测器系统对中子和γ射线的灵敏度。已证实探测器系统对中子和γ射线几乎不敏感。 (4)得出结论：结合上述实验结果得到的特性，可以制作出高信噪比的低能质子探测器。

项目成果

Y. Hosono, H. Nihei, and M. Nakazawa: "Photon Spectrum Emitted from a Thin Ruby Scintillator"(in preparation for publication).

Y. Hosono、H. Nihei 和 M. Nakazawa：“薄红宝石闪烁体发出的光子光谱”（准备出版）。

H.Hihei, Y.Hosono et al.: "Development of a Low-Energy Proton Detector for Measuring the Proton Emitted by Neutron Decay"KURRI Progress Report. No.11084 (1999)

H.Hihei、Y.Hosono 等人：“开发用于测量中子衰变发射的质子的低能质子探测器”KURRI 进度报告。

Y. Hosonom H. Nihei, and M. Nakazawa: "Development of a Low-Energy Proton Detector for Measuring the Proton Emitted by Neutron Decay II"Ext. Abstr. (62th Autumn Meet, 2001) Japan Society of Applied Physics and related Societies. 13a-4-2H

Y. Hosonom H. Nihei 和 M. Nakazawa：“开发用于测量中子衰变 II 发射的质子的低能质子探测器”Ext。

細野米市,二瓶仁,中沢正治: "中性子崩壊時に発生する陽子測定用低エネルギー陽子検出器の開発"第61回応用物理学会学術講演会予稿集. 1. 77 (2000)

Yoneichi Hosono、Hitoshi Nihei、Masaharu Nakazawa：“开发用于测量中子衰变过程中产生的质子的低能质子探测器”第 61 届日本应用物理学会年会论文集（2000 年）。

細野, 二瓶, 中沢: "中性子崩壊時に発生する陽子測定用低エネルギー陽子検出器の開発"第61回応用物理学会学術講演会予稿集. 1. 6p-V-9/I (2000)

Hosono、Nihei、Nakazawa：“开发用于测量中子衰变过程中产生的质子的低能质子探测器”第 61 届日本应用物理学会年会论文集 1. 6p-V-9/I (2000)。