Accession Number : ADA138345

Title :   On the Rate of Energy Input in Thermal Solar Flares.

Descriptive Note : Technical rept.,


Personal Author(s) : Feldman,U ; Doschek,G A ; McKenzie,D L

PDF Url : ADA138345

Report Date : 07 Dec 1983

Pagination or Media Count : 19

Abstract : The rise phases of solar soft X-ray flares observed by X-ray crystal spectrometers on p78-1 are discussed in terms of the rate of change of X-ray flux as a function of time. It is shown that the flux increased exponentially over most of the rise time. The e-folding time TAU has a cut-off at 13 s. Soft X-ray flares with smaller values of TAU are not observed. It is suggested that this phenomenon is due to the ability of the solar atmosphere to absorb the input energy and convert it into a typical soft X-ray flare. For energy input rates that are below a certain critical value the temperature attained by the plasma is around 20,000,000 K, but for values above the critical value, the gas is heated to much higher temperatures T sub e or = 10 to the 8th K, producing a certain class of hard X-ray events. (Author)

Descriptors :   *Solar flares, Energy transfer, Soft x rays, Solar atmosphere, Energy levels, Spectrometers

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE