Methods of determining the density and temperature distribution of a plasma using electromagnetic waves

Abstract

The authors consider a number of methods of determining the density and temperature distributions along the radius of a plasma cylinder. Determination of the electron density and temperature distributions by measuring the electron cyclotron damping or the phase of an electromagnetic wave passing in a straight line through a plasma cylinder as a function of the “sighting” distance. If the electron velocity distribution is not Maxwellian, additional measurements of the absorption or the phase as a function of the magnetic field or of the angle between the direction of the ray and the magnetic field enable one to find the electron velocity distribution function along the magnetic field at each point in the plasma cylinder. Determination of the plasma density distribution from the fraction of a microwave ray passing through a plasma in a direction perpendicular to the magnetic field, and determination of the effective collision frequency distribution from damping of the intensity of the refracted ray. Determination of the temperature of a plasma in a strong magnetic field from the measured frequency-dependence of the absorption of low-frequency electromagnetic waves under conditions of acoustic resonance.