# Accession Number:

## AD0621364

# Title:

## RADIATIVE TRANSFER IN LINES FOR MEDIA IN STATISTICAL EQUILIBRIUM.

# Descriptive Note:

## Scientific rept.,

# Corporate Author:

## HARVARD COLL CAMBRIDGE MASS PRESIDENT AND FELLOWS

# Personal Author(s):

# Report Date:

## 1965-06-25

# Pagination or Media Count:

## 32.0

# Abstract:

The line transfer problem is discussed for a two-level atom and extended to an N-level atom. For N 2 the source function is obtained, and non-linear and linear integro-differential equations are derived expressing the transfer problem subject to the condition of statistical equilibrium. From the differential equation the corresponding integral equations for the line source function are determined, and the integral kernels are discussed for the case of depth-dependent absorption profiles. The line components of the source function are derived for an N-level atom. The corresponding coupled integral equations for the resonance line components of the source function are discussed for the limit of low temperatures, and a method of solution is outlined. An analytic solution is obtained for the case of constant coefficients and integral kernels which are single exponential functions. Author