� 2004. The American Astronomical Society. All rights reserved. Printed in U.S.A. PARTICLE ACCELERATION IN MULTIPLE DISSIPATION REGIONS

Abstract

The sharp magnetic discontinuities that naturally appear in solar magnetic flux tubes driven by turbulent photospheric motions are associated with intense currents. Parker proposed that these currents can become unstable to a variety of microscopic processes, with the net result of dramatically enhanced resistivity and heating (nanoflares). The electric fields associated with such “hot spots ” are also expected to enhance particle acceleration. We test this hypothesis by exact relativistic orbit simulations in strong random phase magnetohydrodynamic 2 5 turbulence that is forming localized super-Dreicer Ohm electric fields ( 10 ≤ E /E ≤ 10) occurring in 2%–15% of the volume. It is found that these fields indeed yield a large amplification of acceleration of electrons and ions and can effectively overcome the injection problem. We suggest in this article that nanoflare heating will be associated with sporadic particle acceleration. Subject headings: acceleration of particles — turbulence Understanding the mechanisms behind the dissipation of magnetic energy in the solar atmosphere is a key ingredient for the solution of several problems related to coronal heating