Comparison of Cesium Iodide and Gold Photocathodes for X-Ray Streak Cameras

摘要

X-ray streak cameras at Lawrence Livermore Laboratory use gold transmission photocathodes for x-ray detection. Other photocathode materials which might provide improved sensitivity without loss of temporal resolution are of interest. Of particular interest are dielectrics such as cesium iodide. Simultaneous measurements of the sensitivity to 500 eV x-rays of both gold and cesium iodide photocathodes in the LLL Soft X-ray Streak Camera were made. Enhanced sensitivity with the Csl photocathodes is reported and no degradation of temporal resolution for 100 ps x-ray pulses is seen. We have established the optimum thickness for maximum sensitivity of gold photocathodes to be 100 A. The maximum sensitivity of cesium iodide was observed for photocathode thickness of 1100 A. (ERA citation 05:027530)