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Solar Physics

, Volume 160, Issue 2, pp 343–352 | Cite as

Evolution of energetic protons in twisted magnetic loops

  • Yun-Tung Lau
  • Reuven Ramaty
Article

Abstract

We study the evolution of an ensemble of energetic (1 GeV) protons in a twisted force-free magnetic loop. The protons are followed with a bounce-average method and they are subjected to collisions with ambient gas and pitch-angle scattering by plasrma turbulence in the loop. The proton loss is initially by drift and later by scattering into the loss cone. Gamma rays are produced by pion decays resulting from nuclear reactions of these lost protons. It is found that in order to have long-lasting protons, one of the following scenarios should hold: (1) For small loops (of length ∼ 2 × 109 cm), the twist angle should be about 2π and the turbulence level below 10−8 erg cm−3. (2) For large loops (≳ 1010 cm), the turbulence level should be below 10−6 erg cm−3. These set the conditions for testing the trapping picture as a viable explanation for the observed eight-hour gamma-ray emission.

Keywords

Nuclear Reaction Twist Angle Turbulence Level Magnetic Loop Large Loop 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Yun-Tung Lau
    • 1
  • Reuven Ramaty
    • 2
  1. 1.Institute for Plasma ResearchUniversity of MarylandCollege ParkUSA
  2. 2.Laboratory for High-Energy AstrophysicsNASA/Goddard Space Flight CenterGreenbeltUSA

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