Absorption Coefficients of Nitrogen Oxide in the Vacuum Ultraviolet

Abstract

Using a photoelectric method described previously, absorption coefficients of nitrogen oxide were measured in the spectral region 1100–2300A. Pressures from 0.3- to 100-mm Hg were used in the absorption cell with LiF windows. A continuous absorption spectrum was found in the region 1100–1400A where the absorption coefficients varied from about 40 cm−1 to 200 cm−1. At the Lyman alpha line of hydrogen at 1216A the value was 67.5 cm−1. A number of weak diffuse bands was also observed in the same region. These bands suggest preionization, since they appeared at wavelengths below about 1320A. The relative intensity distribution of the known bands (β, δ, ∊, γ) at longer wavelengths were obtained at various pressures and are discussed.