# Accession Number:

## AD0271735

# Title:

## A THEORY OF INCOHERENT SCATTERING OF RADIO WAVES BY A PLASMA IN A UNIFORM MAGNETIC FIELD

# Descriptive Note:

# Corporate Author:

## CHALMERS UNIV OF TECHNOLOGY GOTEBORG (SWEDEN)

# Personal Author(s):

# Report Date:

## 1961-12-01

# Pagination or Media Count:

## 1.0

# Abstract:

A general expression for the frequency spectrum of radio waves scattered by the random thermal fluctuations of electron density in a plasma in thermal equilibrium and in a magnetic field is derived. The derivation is based on the generalized Nyquist noise theorem used in an earlier paper. The exact result is then simplified by means of an approximation which amounts to assuming the velocity of light to be infinite. It is shown that this approximation is quite adequate for ionospheric applications of the theory. Next it is proved, without appealing to any approximation, that the magnetic field can never alter the total scattered signal power it can only redistribute this power over the spectrum. Finally, the detailed shape of the frequency spectrum of the scattered signal is examined. Analytic expressions are given for certain limiting cases, but for the cases of most interest, numerical methods must be used. Author