MECHANISM OF SELF-QUENCHING STREAMER BY MEANS OF UV-LASER LIGHT

紫外激光自淬流光机理

• 批准号: 05680422
• 负责人: KOORI Norihiko
• 金额: $ 1.47万
• 依托单位: UNIVERSITY OF TOKUSHIMA
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680422/
• 关键词: SELF-QUENCHING STREAMER; GAS COUNTER; GAS MULTIPLICATION; PHOTO-IONIZATION; PROPORTIONAL COUNTER; 自己消滅ストリーマー

The self-quenching streamer (SQS) mode of gas counter operation is a basically important operation mode as well as the established ionization-chamber, proportional, and GM modes. The SQS mode indicates a very high gas multiplication, and furthemore very good counting rate characteristics that are superior to the GM mode by about one order. In the present pfoject, the mechanism of the SQS mode, in which the photoionization process may be important, was investigated by means of UV-laser light.The results are summarized as follows :1) The counting rate characteristics of SQS tubes are improved by adding the second quenching gas vapor such as methylal to usually used counting gas mixture of Ar-isoC_4H_<10>. It encourages us to use SQS tubes in high radiation dose field near reactor sites.2) The mechanism of SQS produced by alpha-rays was revealed by optical observation of streamers with image intensifiers. Since two streamers are generated by electrons that come from ionization tracks by alpha-rays, high electron-density ionization-tracks accelerate the SQS transition.3) The SQS transition is observed by means of UV-laser light, Size of electron avalanches depends on the laser power and the ionization proceeds through the multiple photo-absorption process. The SQS transition is, therefore, similar to those by charged particles such as alpha-rays.4) The contribution from excitation of meta-stable states are not so clear, because the ionization by UV laser light and photoionization are to be identified. It should be studied furthemore.

气体计数器操作的自猝灭流光（SQS）模式是一种基本重要的操作模式，以及已建立的电离室、比例和GM模式。SQS模式显示了非常高的气体乘法，并且具有非常好的计数率特性，比GM模式高出约一个数量级。在本项目中，利用紫外激光研究了SQS模式的机理，其中光电离过程可能是重要的。结果表明：1)在常用的Ar-isoC_4H_<10>的计数气体混合物中加入甲缩醛等二次淬火气体蒸汽，改善了SQS管的计数率特性。它鼓励我们在反应堆场址附近的高辐射剂量场使用SQS管。2)通过带像增强器的光阑光学观测，揭示了α射线产生SQS的机理。由于两个飘带是由来自α射线电离轨迹的电子产生的，高电子密度的电离轨迹加速了SQS跃迁。3)利用紫外激光观察SQS跃迁，电子雪崩的大小取决于激光功率，电离过程是通过多次光吸收过程进行的。因此，SQS跃迁与带电粒子（如α射线）的跃迁相似。4)亚稳定态激发的贡献不太清楚，因为紫外激光的电离和光电离还有待确定。这应该进一步研究。

项目成果

A.Nohtomi: ""Modelling of SQS Propagation Induced by Alpha Rayin Gas Counters"" Proc.IEEE 1994 Nuclear Science Symposium. NSS-05-39 (1994)

A.Nohtomi：“Alpha Rayin 气体计数器诱导的 SQS 传播建模”Proc.IEEE 1994 核科学研讨会。

N.Koori: "Self-Quenching Streamer(SQS)Tube with Ar-isoC_4H_<10>-Methylal Mixture" Jour.Nucl.Sci.Tech.30. 974-980 (1993)

N.Koori：“含有 Ar-isoC_4H_<10>-甲基缩醛混合物的自淬流光 (SQS) 管”Jour.Nucl.Sci.Tech.30。

A.Nohtomi, K.Narita, T.Sakae, Y.Uozumi, M.Matoba, and N.Koori: ""Modelling of SQS Propagation Induced by Alpha Ray in Gas Counters"" Proc.1994 IEEE Nuclear Science Symp.NSS-05-39. (1994)

A.Nohtomi、K.Narita、T.Sakae、Y.Uozumi、M.Matoba 和 N.Koori：“气体计数器中 Alpha 射线诱导的 SQS 传播建模”Proc.1994 IEEE 核科学 Symp.NSS-

H.Nohtomi: "Optical Observation of Self-Quenching Streamers by α- and β-Rays" Proc.IEEE 1993 Nuclear Science Symposium. NSS12-4 (1993)

H.Nohtomi：“α 射线和 β 射线对自淬灭流光的光学观察”Proc.IEEE 1993 年核科学研讨会 (1993)。

N.Koori, A.Nohtomi, and M.Hirota: ""Self-Quenching Streamer (SQS) Tube with Ar-isoC_4H_<10>-Methylal Mixture"" J.Nucl.Sci.Tech.30, no.10. 974-980 (1993)

N.Koori、A.Nohtomi 和 M.Hirota：“具有 Ar-isoC_4H_<10>-甲基醛混合物的自淬流光 (SQS) 管””J.Nucl.Sci.Tech.30，第 10 期。