Optical radiation in breakdown of the acceleration gap of a forevacuum pressure, wide-aperture, plasma-cathode, pulsed electron source

Abstract: We have investigated the spectrum of optical radiation during breakdown in the acceleration gap of a wide-aperture, plasma-cathode, pulsed electron source based on a vacuum arc discharge in the forevacuum pressure range (3–20 Pa). The analysis shows that breakdown considerably increases the spectral line intensity and results in additional gas and metal lines. The spectrum is dominated by atomic and molecular lines from the working gas. The presence of metal lines under breakdown conditions suggests that cathode spots arise at the emission electrode, assisting the gas discharge in the acceleration gap.

Keywords: plasma electron source, pulsed electron beam, arc discharge, acceleration gap, breakdown