Ionization yields, total absorption, and dissociative photoionization cross sections of CH4 from 110 to 950 Å

Abstract

Absolute absorption and photoionization cross sections of methane have been measured with an accuracy of about 2% or 3% over most of the wavelength range from 950 to 110 Å. Also, dissociative photoionization cross sections were measured for the production of CH⁺₄ , CH⁺₃ , CH⁺₂ , CH⁺, and C⁺ from their respective thresholds to 159 Å, and for H⁺ and H⁺₂ measurements were made down to 240 Å. Fragmentation was observed at all excited ionic states of CH₄.