Measurement of excited-state densities during high-current operation of a hydrogen thyratron using laser-induced fluorescence

The population of the n=2 level of atomic hydrogen and the collisional relaxation rates of the n=3 and n=4 levels during the conductive phase in the positive column of a high-current ( J∼100–400 A/cm2) pulse in a hydrogen thyratron were measured. These results demonstrate laser-induced fluorescence to be a useful in situ diagnostic for high-current switch plasmas.