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Comparing Solar-Flare Acceleration of >-20 MeV Protons and Electrons Above Various EnergiesA large fraction (up to tens of percent) of the energy released in solar flares goes into accelerated ions and electrons, and studies indicate that these two populations have comparable energy content. RHESSI observations have shown a striking close linear correlation between the 2.223 MeV neutron-capture gamma-ray line and electron bremsstrahlung emission >300 keV, indicating that the flare acceleration of >^20 MeV protons and >300 keV electrons is roughly proportional over >3 orders of magnitude in fluence. We show that the correlations of neutron-capture line fluence with GOES class or with bremsstrahlung emission at lower energies show deviations from proportionality, primarily for flares with lower fluences. From analyzing thirteen flares, we demonstrate that there appear to be two classes of flares with high-energy acceleration: flares that exhibit only proportional acceleration of ions and electrons down to 50 keV and flares that have an additional soft, low-energy bremsstrahlung component, suggesting two separate populations of accelerated electrons. We use RHESSI spectroscopy and imaging to investigate a number of these flares in detail.
Document ID
20100021364
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Shih, Albert Y.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 24, 2013
Publication Date
May 23, 2010
Subject Category
Solar Physics
Meeting Information
Meeting: 216th American Astronomical Society (AAS) Meeting
Location: Miami, FL
Country: United States
Start Date: May 23, 2010
End Date: May 27, 2010
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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