Effective ionization coefficients for low current dc discharges in alcohol vapours at low pressure

Abstract

This paper presents results for effective ionisation coefficients (αeff/ N, N—gas density) obtained from the breakdown voltage and emission profile measurements in low-pressure dc discharges in vapours of alcohols: methanol, ethanol, isopropanol, and n-butanol. Our results for αeff/ N are determined from the axial emission profiles in low-current Townsend discharge and lay in the interval of reduced electric field E/N (E—electric field, N—gas density), from 1 kTd to 8.8 kTd. We also give a comparison of our experimental results with those from the available literature. Our data cover the high E/N range of the standard operating conditions and in the region where other data are available we have a good agreement. Graphic abstract: [Figure not available: see fulltext.]