Rotating crystal cube as a variable shutter for use with synchrotron radiation

摘要

Abstract: A beam chopper together with the temporal structure of x-rays emitted by a synchrotron storage ring can be utilized to generate x-ray bursts of variable length and time separation. A Si cube, cut for diffraction from the (220) planes, was mounted to a low-speed motor to produce a beam chopper based upon the Darwin width of the crystal. An x-ray pulse, consisting of an envelope of individual pulses characterizing the loading pattern of the storage ring, was transmitted. The width of the transmitted pulse and the time between pulses was varied by varying the rotation frequency of the Si cube. Pulses as short as approximately equal 75 ps or as long as approximately equal 4 microseconds were transmitted with pulse separation spanning from 4 ms to 167 ms. !2