Pulse compression effect in a laser-driven flash X-ray tube.

The performance characteristics of a high-vacuum discharge flash x-ray tube, such as dose, maximum dose rate, discharge delay time, and pulse width, can be improved by triggering the tube with a laser-produced plasma at the cathode. The system consists of an open flash x-ray diode of classical coaxial electrode geometry, driven at 50 kV by a 10 Omega, 69 ns transmission line and a neodymium:yttrium aluminium garnet laser of 10 ns pulse width, which is focussed onto the cathode rim. It could be demonstrated that already at small incident laser energy a significant x-ray pulse compression could be achieved, which also goes in parallel with an increase in dose output. Experiments with laser energies at 110 mJ indicate a saturation in optimum tube performance.