Interplanetary Gas. IV. Neutral Hydrogen in a Model Solar Corona.

The problem of the distribution of neutral hydrogen in a model solar corona is investigated Hydrogen is considered as created by recombinations, destroyed by collisions and photoionization, and transported by diffusion. The diffusion cross-section is taken as that for charge ezchange, and the effects of radiation pressure from solar Lyman-a are included. A model with an electron density near the orbit of earth of the order of 1O2/cm3 yields sufficient hydrogen beyond the earth to back-scatter solar Lyman-a and produce the observed night-sky radiation.