Anode heating by x rays in high power diodes

We present a possible mechanism for the heating creation of anode plasma in pulsed power machines. It involves the radiation emitted by the whisker plasma situated near the surface of the opposing electrode. We show that deposited energies in excess of 400 J/g are possible in typical modern machines in regions of the vacuum feed where the pulse magnetic field attains peak values on the order of 100 kG. If the assumption is made that the initial temperature of the cathode plasma is about 5 eV and that its mass depth is in excess of 10−7 g/cm2 the anode surface is raised to over 600 °C during short (50 ns) pulses, thereby liberating desorbed gas atoms which the x rays may then ionize.