Comparison of high-resolution electric field measurements in a hollow cathode glow-discharge operated in hydrogen and deuterium

Abstract

High-resolution measurements of the electric field strength in a hollow cathode discharge operated with deuterium gas are presented. The electric field strength is determined via Stark effect splitting of the 2S level of deuterium atoms using Doppler-free two-photon laser spectroscopy. The results are compared with equivalent measurements when the discharge was operated in hydrogen. The measured electric fields are analyzed using two classical models to obtain valuable parameters about the discharge dynamics, such as the energy of the ions and their mean free path in the cathode region. This information is compared with previous results for hydrogen and allows insight into the differences when gas discharges are operated with one of the isotopes.