上海光源新型一维位置灵敏电离室研制

Development of 1-D position-sensitive ionization chamber used in SSRF

研制了一台一维位置灵敏电离室。该电离室的收集电极由两块完全一样的相互独立并彼此绝缘的单元构成,每个单元有两路劈裂式极板,根据输出的电流信号可获得X光束的强度和位置。该电离室在上海光源(SSRF)生物大分子晶体学光束线上进行了实验测试,测试中采用了一个标准电离室作为强度测量对照。一维位置灵敏电离室被固定在一维电控滑台上,在水平方向上移动电控滑台逐步扫描测试光束的位置。测量时,光子能量为8keV,扫描范围为10mm,重复扫描12次;测试内容包括电离室的坪区、线性度、位置测量精度及光强。结果表明,该电离室的线性度较好,位置测量精度好于20μm,线性测量范围为6mm。它将安装在生物大分子晶体学光束线站上用于光束稳定性的监测。

A one-dimensional position-sensitive ionization chamber has been designed and fabricated. The cathode of this ionization chamber consists of two selfsame units that are insulated from each oth er and each unit is divided into two-way cleft plates. From current output signals, it can offer the in tensity and position of crystallography beamli X-ray beam. The ionization chamber was installed on a SSRF macromolecular ne and its performance was tested. In the test, a standard ionization chamber was used for the comparison of beam intensity measurement. The one-dimensional position-sensitive ionization chamber was fixed on a high precision linear motor stage and was driven on horizontal direction to scan the beam position step by step, In which the beam energy was set to be 8 keV and the scanning range to be 10 mm. The position scan was repeated 12 times. The tested specifications were plateau curves, linearity, position resolution and the intensity of beam. The results indicate that the 1-D position-sensitive ionization chamber has a good linearity and its position resolution is better than20μm and linear measuring range is 6 mm. Moreover,it will be installed on the beamline of SSRF for monitoring the stability of beam.