Absorption Coefficients of Water Vapor in the Vacuum Ultraviolet

Abstract

Absorption coefficients of water vapor in the region 1060–1860A were obtained by a photoelectric method described previously. Pressures (0.08 to 8 mm Hg) of water vapor in the absorption cell were measured with an Alphatron gauge. In the region 1860–1500A, the absorption coefficients were between the values reported by two groups of investigators. Oscillator strengths of two continua, 1150–1430A and 1430–1860A, were found to be 0.05 and 0.041, respectively. At Lyman alpha the absorption coefficient was 387 cm−1. Twelve weak diffuse bands forming a progression in the region 1250–1450 and a number of bands in the region 1060–1250 were observed. The absorption coefficients of the continua and bands were independent of pressure, except for some of the bands in the region 1060–1250A.