Characterization of multicapillary dielectric cathodes

Abstract

Parameters of the plasma and electron beam produced by a multicapillary cathode in a diode powered by a ∼200 kV, ∼300 ns pulse are presented. It was found that the source of electrons is the plasma ejected from the capillaries. Inside the capillaries this plasma obtains electron density and temperature of ∼8× 1015 cm-3 and ∼5 eV, respectively. In the vicinity of the cathode, the density and temperature of the plasma electrons were found to be 2× 1014 cm-3 and 4.5 eV, respectively, for electron current density of ∼40 A cm2. It was shown that the plasma expansion velocity is in the range of (1-2) × 106 cms for current density of >12 A cm2. © 2007 American Institute of Physics.