Spatial and temporal characteristics of the X-ray emitted by a 1-J 50-ns vacuum discharge

The X-ray emission from a source based on a small vacuum discharge is studied. Two different X-ray pulses whose intensities vary with the anode-cathode distance are identified. Time integrated pinhole images show that the whole anode and the teflon insulator emit X-rays. Some of the X-ray emission is found to originate also in the vicinity of the tungsten anode. The temporal behavior of the X-ray varies with respect to the distance between the anode and the cathode. Three different cathode geometries are tested: hollow cathode, hollow conical cathode, and massive or needle cathode. The spatial distribution of the X-ray sources is obtained by means of a sensitive imaging device. Some X-ray spots that appear in the discharge gap near the anode tip are similar to hot spots found in more powerful discharges