Calculation of the work function of the cathode plasma under explosive electron emission

The initial stage of explosive electron emission represents is of most interest in the case of production of subnanosecond and picosecond electron beams in devices with explosive-emission cathodes. In this work we have developed, based on the electron density functional theory, a self-consistent model that allows one to calculate the work function of the cathode spot plasma in the range from the metal density to a density of ~10¹⁸-10²⁰ cm^-3 in the interval of electron temperatures from zero to ~5 eV. Calculations have been performed for a copper cathode. It has been shown that as the concentration of free charge carriers at the front the cathode flare is decreased from 10²³ to 10²⁰ cm^-3, the work function of the plasma decreases to about one fifth.