X光胶片响应曲线的实验标定

Calibration of response curves for X-ray film

介绍了天津ⅢX光胶片在北京同步辐射源3W1B装置上进行绝对响应标定的一种实验方法。实验中采用快门控制曝光时间,标准探测器记录积分光强,从而得到胶片接收到的绝对光强,并用黑密度计扫描胶片得到光学黑密度。数据处理中通过对快门响应的标定和对光源分布不均匀性的处理来减小光强的不确定度。实验得到了胶片在1 keV和1.5 keV两个能点绝对光强与黑密度之间的绝对响应实验数据,并用Hen-ke的理论公式拟合得到绝对响应曲线。

A calibration method of absolute response for TianjinⅢ X-ray film on Beijing Synchrotron Radiation Facility was introduced. In experiment,a shutter and standard detector were used to control the exposure time and integrated light intensity, hence the absolute light intensity recorded by the film could be obtained, and optical density was obtained by scanning the film with densitometer. In data processing, the shutter response was calibrated and the non-homogeneous source distribution was studied, which could reduce the uncertainty of light intensity. The experimental data of the absolute response between absolute light intensity and the optical density at photo energy of 1keV and 1.5keV were obtained respectively, the experimental results were fitted with Henke’s theoretic formula to obtain absolute response curves.