The Origin of Low-Energy Anomalous Cosmic Rays at the Solar-Wind Termination Shock
Abstract
When Voyagers 1 and 2 each crossed the termination shock of the solar wind, there were very large enhancements of 40keV-5 MeV ions. The fluxes were seen to rise very near the time of the shock crossing suggesting that the shock itself is the source of the accelerated particles. Using self-consistent two-dimensional hybrid simulations of the termination shock, we show that low-energy anomalous cosmic-rays are accelerated ``core'' interstellar pickup ions (those that have not previously undergone any significant energization) by the termination shock via a combination of shock drift acceleration and particle scattering in meandering magnetic fields in the vicinity of the shock. In addition, our simulations are also consistent with other measurements made by Voyager 2 in which the details of the shock microphysics, including magnetic field at high resolution, plasma density, temperature and flow speed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMSH23C..06G
- Keywords:
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- 7514 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Energetic particles;
- 7807 SPACE PLASMA PHYSICS / Charged particle motion and acceleration;
- 7851 SPACE PLASMA PHYSICS / Shock waves