超低透过率的测定

本文介绍了用波长为632.8nm的He—Ne激光器作为光源测量透射比小于10^-7/cm²的X光滤光片针孔透射比的方法。为了测量这样低的透过率,我们设计和安装了反射式超低透过率测定装置。用黑色玻璃作为反射式衰减元件,用光电倍增管作为接收器,用数字电压表作为读数仪表。同时,还用中性玻璃滤光片组作为透过式衰减器,也测量了超低透过率。两种方法都得出满意的结果。

Measurement of the Ultralow Transmitances

This paper presents a method to for testing optical transmitances of the X-ray filters as low as 10^-7～10^-8/cm². In this method we used a He-Ne laser operating at 632.8nm wavelength as a light source. In order to measure such low transmitances, we designed and equipped a ultrolow transmitance measurement device of retlection mode, using a photomultiplier as the detector, a digital voltmeter as the reading device. Moreover, we also used a group of grey absorbing filters as the transmiting attenuator to measure the ultralow transmotances. Both methods have given satisfactory results.