Absorption Cross Sections of Methane and Ammonia in the Vacuum Ultraviolet

摘要: Absorption cross sections of methane and ammonia for electromagnetic radiation in the range from 1300 A to 374 were obtained with a two‐meter radius curvature, grazing incidence vacuum spectrograph. For 85 wavelengths measured. Starting σ = 14 Mb (1 10—18 cm2) at A, absorption first increased slowly then rose more rapidly maximum 56 960±278 corresponding ionization potential methane. The decreased gradually Mv A. total f‐value pertaining transitions 2p‐electrons was found be 6.1. ammonia, 100 Band appeared longer wavelengths. continuous began near 1210 extended shorter structure contour suggested existence two continua: weaker one 21 1130±20 larger its 34 730±20 These maxima corresponded limits outer electrons ammonia. 5.9.