新型电离室的设计与应用研究

Designing and applying study of a new iono-chamber

目的 设计一种新型的自动曝光控制 (AEC)用电离室式X射线传感器。方法 根据电离理论及AEC的具体要求进行设计 ,并对其进行临床应用研究。结果 新研制的复式 3野电离室 :(1)双阴极复式结构 ,与单层电离室具有相同的灵敏体积 ,但却使电极间距d减小 1/ 2 ;(2 )保护环与双阴极板构成双重屏蔽 ,抗电磁干扰能力强 ;(3)所用轻质材料对X线吸收小 ,不在胶片上形成干扰影像。结论 新型电离室性能稳定 ,工作可靠 ,效果良好 ,用于无AEC装置X线机的改造 。

Objective To design a new X-ray sensor of iono-chamber type to achieve automatic exposure control(AEC) of the X-ray machine. Methods We designed the chamber acording to the ionization theory and the requirements of automatic exposure control. Results (1) The device had double-negative poles, so the distance between positive and negative poles was 1/2 shorter and its test-volume was equal to odd-negative pole. (2)It had good property of electromagnetism-resistance because of the double shielded design by double-negative poles and screen-rings.(3) Iono-chamber was made of low-density material, so it had low absorb-ratio of X-ray and could not form image on film. Conclusion The property of the device was steady and reliable. It had applying and spreading value.