The present letter extends the prior findings on self-induced heating of solid state field emission devices. It was found that a vacuum diode (base pressure ∼10−9 Torr), that makes use of graphite-rich polycrystalline diamond as cathode material, can switch from diode regime to resistor regime, to glow discharge plasma regime without any external perturbation, i.e. all transitions are self-induced. Combined results of in situ field emission microscopy and ex situ electron microscopy and Raman spectroscopy suggested that the nanodiamond cathode of the diode heated to about 3000 K which caused self-induced material evaporation, ionization and eventually micro-plasma formation. Our results confirm that field emission, commonly called cold emission, is a very complex phenomenon that can cause severe thermal load. Thermal load and material runaway could be the major factors causing vacuum diode deterioration, i.e. progressive increase in turn-on field, decrease in field enhancement factor, and eventual failure.
@article{arxiv.1811.04186,
title = {Field Electron Emission Induced Glow Discharge in Nanodiamond Vacuum Diode},
author = {Stanislav S. Baturin and Tanvi Nikhar and Sergey V. Baryshev},
journal= {arXiv preprint arXiv:1811.04186},
year = {2019}
}