Initial development of X-ray diodes with transmission photocathode

Based on emission mode of transmit cathode and the principle of FXRD, a transmit cathode for XRD was designed and manufactured. A sample with a cathode made up of 550 nm CH and 50 nm Au was used for preliminary experiments on SG-Ⅲ prototype facility. Firstly the influence of direct X-ray was evaluated using an XRD with reflective cathode. The results show that the XRD with -1500 V bias voltage could eliminate the influence of X-ray arrived at the anode for XRD with transmission cathode. Then when main lasers and the ninth laser were operating on SG-Ⅲ prototype facility, the transmission cathode XRD with negative bias voltage captured normal signals. The results show that the second peak signal delay 3.01 ns by the first peak, which is in accord with the time sequence of main lasers and the ninth laser. The capability of temporal resolution can satisfy requirements of experiments.