A Condition on Uniform Field Breakdown in Electron-Attaching Gases

The usual form of breakdown potential curves indicates that at large pd an asymptotic value of E/p seems to exist, below which breakdown does not occur. A study of the equation for steady-state current in electron-attaching gases suggests that this (E/p)ₗᵢₘ is nearly that for which the ionization and attachment coefficients are equal. Substantial agreement is found in CCl₄, CF₃SF₅, CCl₂{F}₂$, S${F}₆$, air, and ${O}₂$ between values of ${(E/p)}ₗᵢₘ$ so determined and those found experimentally. The order of ${(E/p)}ₗᵢₘ$ for these gases corresponds closely to that of their dielectric strengths.