Quenching thermal instability in the body of a thermionic arc cathode

The possibility of quenching the instability causing the appearance of spots on thermionic cathodes of high-pressure arc discharges is demonstrated by means of numerical simulations and experimentally. This possibility stems from the fact that the instability is of a thermal nature and therefore slow. While of significant interest by itself, this possibility may be exploited to prevent in real time the formation of cathode spots in arc devices.