34th Solar Physics Division Meeting, June 2003
Session 22 RHESSI Results III
Oral, Thursday, June 19, 2003, 9:00-10:30am, Auditorium

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[22.01] Stochastic Acceleration of Protons and Electrons: Gamma-Ray Emissions from LT and FP of Solar Flares

V. Petrosian (Dept. of Physics and Applied Physics, CSSA, Stanford Univ.), S. Liu (CSSA, Dept. of Physics, Stanford Univ.)

Stochastic acceleration by turbulent plasma waves, induced perhaps by magnetic reconnection or shocks near the top of flaring loops, seems to be the most viable scenario for the production of nonthermal particles detected during the impulsive phase of solar flares. Previous studies mostly focused either on electron acceleration or on that of protons. A comprehensive comparative study of the two has not been done. In this paper we present some preliminary results of our study on stochastic acceleration of protons and electrons by parallel propagating plasma waves in a cold magnetized electron-proton plasma. The aim of this work is to investigate the characteristics of protons and electrons accelerated from a thermal background plasma by a spectrum of turbulent plasma waves. The simplest form of such a model, where the source is homogeneous and there is energy equipartition among different wave modes, with reasonable parameters of the background plasma and turbulence can produce the required (by observations) electron spectra. However, the corresponding proton spectra may not be compatible with observations, and vice versa. Results from our study of this aspect will be described. We have explored the model parameter space and will describe the conditions for production of comparable gamma-ray continuum (by electron bremsstrahlung) and line emission (by accelerated proton and ions), and the conditions for production of the so-called electron dominated or gamma-ray line dominated flares.

The work at Stanford is supported by NASA grants NAG5-12111, NAG5 11918-1, and SUB2001-402-01 through University of Alabama in Huntsville (PI: J. Miller).


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The author(s) of this abstract have provided an email address for comments about the abstract: liusm@stanford.edu

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