The development of two-dimensional position-sensitive counter for high-energy X rays provided from synchrotron radiation facility

同步辐射装置高能X射线二维位置敏感计数器的研制

• 批准号: 06452071
• 负责人: ITO Shin
• 金额: $ 3.52万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06452071/
• 关键词: synchrotron radiation; high-energy X rays; two-dimensional position-sensitive counter; gas counter; drift method; high-pressure counting gases; ガス検出器; 高気圧計数ガス

In this research, we have made basic studies for the development of two-dimensional position-sensitive detector for high energy X rays of 10 - 100keV range, being based on the drift chamber principle. Our achievements are as follows :1) Operational mechanism of high-pressure proportional counter in the region of limited proportionality (RLP) (a) Detailed analysis was performed for the halo effect due to characteristic X rays, and the response of proportional counter caused by this effect was fully explained. It was first found that, in RLP,the degree of gas amplification for the halo events is greater than that for the photo-peak events. From the practical view-point, this fact helps since a simple pulse-height selection is able to exclude the halo events which is known to deteriorate position resolution. The results are published in the article No. (1). (b) It was confirmed that the sudden change of avalanche mode due to structural change of primary-electron cloud exists in 7-atm Ar+3 … More 0% CH_4. (the article No. (2)) (c) The feasibility of our position-sensitive proportional counter (PSPC) was examined in charged-particle accelerator experiment. The result showed that high-energy (position) resolving power of the PSPC enables to analyze trace elements to be studied in PIXE.(the article No. (4)) The performance of the PSPC for 10-60 KeV high-energy photon beams was tested in KEK Photon Factory. Fairly good position resolution of 122mum (fwhm) for 20-keV X rays and 140mum for 35-keV X rays were obtained. A part of the results is given in the article No. (3).2) Fabrication of drift detector for X rays (a) A drift detector for X rays with a large sensitive area of 110 x 110 mm^2 was made. The drift space consists of field wires of 25 layrs in drift direction and 4 laryers in counter-depth direction. 4 anode wires are extended for the 4 layrs, the thicknesses of which are 2,4,6 and 8 mm, respectively. (b) The potential distribution was calculated and the adequate flat potential for the 6-mm layr is realized. It was found that the distribution of the potential near the anode wire is important to efficiently collect primary electrons. (c) Test experiments of the drift counter were carried out by using 5-7 Mev proton beams. Owing to the window materials such as Kapton films, fine collimation of the beam was not possible. The beam broadening is peculiar aspect for the charged particles, but not the case for X rays. Thus, it is hoped that, in the well-collimated photon beam experiment scheduled in this June, much better result can be obtained. Less

本研究基于漂移室原理，为开发10~100keV范围高能X射线二维位敏探测器进行了基础研究。我们的研究成果如下：1）高压正比计数器在有限比例区域（RLP）的工作机理（a）对特征X射线产生的光晕效应进行了详细分析，充分解释了该效应引起的正比计数器的响应。首次发现RLP中光晕事件的气体放大程度大于光峰事件。从实际的角度来看，这一事实很有帮助，因为简单的脉冲高度选择就能够排除已知会降低位置分辨率的光晕事件。结果发表在第（1）号文章中。 (b) 证实7-atm Ar+3 … More 0% CH_4 中存在由于一次电子云结构变化而引起的雪崩模式突变。 （第(2)条） (c) 在带电粒子加速器实验中检验了我们的位置敏感正比计数器（PSPC）的可行性。结果表明，PSPC的高能（位置）分辨能力能够分析PIXE中待研究的微量元素。（第（4）号文章）PSPC对10-60 KeV高能光子束的性能在KEK光子工厂进行了测试。 20-keV X 射线获得了 122mum (fwhm) 的良好位置分辨率，35-keV X 射线获得了 140mum 的相当好的位置分辨率。部分结果在第（3）号文章中给出。2）X射线漂移探测器的制作（a）制作了具有110×110mm^2大敏感面积的X射线漂移探测器。漂移空间由漂移方向25层、反深度方向4层现场导线组成。 4根阳极丝延伸4层，厚度分别为2、4、6、8mm。 (b) 计算了电势分布，并实现了 6 毫米层的足够平坦电势。研究发现，阳极丝附近的电势分布对于有效收集初级电子非常重要。 (c) 使用5-7 Mev质子束进行漂移计数器的测试实验。由于使用 Kapton 薄膜等窗口材料，无法实现光束的精细准直。束流展宽是带电粒子的特殊之处，但 X 射线则不然。因此，希望在今年6月份的准直光子束实验中能够获得更好的结果。较少的

项目成果

Shin Ito: "Development of Position-Sensitive Proportional Counter for High-Resolution X-Ray Measurement" Activity Report of Tandem van de Graaff Accelerator 1995, Department of Physics, Faculty of Science, Kyoto University. (in press).

Shin Ito：“用于高分辨率 X 射线测量的位置敏感比例计数器的开发”1995 年 Tandem van de Graaff 加速器活动报告，京都大学理学院物理系。

Shin Ito: "Characteristic Counter Response of Position-Sensitive Proportional Counter Filled with High-Pressure Counting Gases" KEK Photon Factory Activity Report. 1993. 429 (1994)

Shin Ito：“充满高压计数气体的位置敏感比例计数器的特征计数器响应”KEK Photon 工厂活动报告。

Shin Ito: "Gas ampliffication of proportional and SOS modes observed as a function of the radial distance of the position of primary innization" Nucl.Instr.and Meth. A348. 297-302 (1994)

Shin Ito：“观察到比例和 SOS 模式的气体放大作为初级内化位置的径向距离的函数”Nucl.Instr.and Meth。

Shin Ito: "Effect of self-induced space charge in a high pressure position-sensitive proportional counter" Nucl. Instr. and Meth.A368. 738-744 (1996)

Shin Ito：“高压位置敏感正比计数器中自感空间电荷的效应”Nucl。

Shin Ito: "Gas amplification of proportional and SQS modes observed as a function of the radial distance of the position of primary ionization" Nucl. Instr. and Meth.A348. 297-302 (1994)

Shin Ito：“观察到的比例和 SQS 模式的气体放大作为初级电离位置的径向距离的函数”Nucl。