Robert Lin
Space Sciences Laboratory
University of California at Berkeley
Abstract:
The Sun is the most energetic particle accelerator in the solar system, accelerating ions up to 10s of GeV and electrons to 100s of MeV in both large solar flares and fast coronal mass ejections. Solar flares are the most powerful explosions in the solar system, releasing up to 10^32 -10^33 ergs in 100-1000 s. The flare-accelerated ~10-100 keV electrons (and >~1 MeV/nucleon ions in large flares) appear to contain a significant fraction, ~10-50%, of this energy, indicating that the particle acceleration and energy release processes are intimately linked. The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) space mission (launched 2002) provides imaging (to ~2 arcsec) spectroscopy (~1 keV FWHM) of flare X-ray/gamma-ray continuum and gamma-ray lines emitted by energetic electrons and ions, respectively, over the energy range from 3 keV to 17 MeV. Here I will describe the novel RHESSI instrumentation and review the results on solar flares.