Accession Number : AD0743124

Title :   Free-Free Absorption of Gyrosynchrotron Radiation in Solar Microwave Bursts,

Corporate Author : STANFORD UNIV CALIF INST FOR PLASMA RESEARCH

Personal Author(s) : Ramaty,Reuven ; Petrosian,Vahe

Report Date : 28 APR 1972

Pagination or Media Count : 27

Abstract : A model for solar microwave bursts is considered in which over a broad frequency band the flux density is a slowly varying function of frequency. It is proposed that such an essentially flat spectrum could result from free-free absorption of gyrosynchrotron emission of nonthermal electrons accelerated in solar flares. The theory of gyrosynchrotron radiation is reviewed, and simplified formulae for the Razin effect, selfabsorption and gyroresonance absorption are given and their range of validity is discussed. Using these results the thermal electron density, temperature, emission measure, magnetic fields and number of nonthermal electrons in the emitting region are evaluated for a flare with a flat microwave spectrum. (Author)

Descriptors :   (*SOLAR RADIATION, MICROWAVE FREQUENCY), SOLAR FLARES, PLASMAS(PHYSICS), ELECTRON DENSITY, TEMPERATURE, MAGNETIC FIELDS, ABSORPTION SPECTRA

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE