PARTICLE-ACCELERATION AND ENTROPY CONSIDERATIONS

Citation
Jc. Brown et al., PARTICLE-ACCELERATION AND ENTROPY CONSIDERATIONS, Astronomy and astrophysics, 299(2), 1995, pp. 629-634
Citations number
17
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046361
Volume
299
Issue
2
Year of publication
1995
Pages
629 - 634
Database
ISI
SICI code
0004-6361(1995)299:2<629:PAEC>2.0.ZU;2-E
Abstract
Possible entropy constraints on particle acceleration spectra are disc ussed. Solar flare models invoke a variety of initial distributions of the primary energy release over the particles of the flare plasma - i e., the partition of the energy between thermal and nonthermal compone nts. It is suggested that, while this partition can take any value as far as energy is concerned, the entropy of a particle distribution may provide a useful measure of the likelihood of its being produced for a prescribed total energy. The Gibbs' entropy is calculated for severa l nonthermal isotropic distribution functions f, for a single particle species, and compared with that of a Maxwellian, all distributions ha ving the same total number and energy of particles. Speculations are m ade on the relevance of some of the results to the cosmic ray power-la w spectrum, on their relation to the observed frequency distribution o f nonthermal flare hard X-ray spectrum parameters and on the additiona l energy release required to achieve lower entropy fs.