HR: 0800h
AN: SH41A-0307    [Abstracts]
TI: Joint Fitting of the Gamma-Ray Spectrum and Neutron-Capture Line Decay Profile to Constrain Ion Acceleration in Large Flares
AU: * Naiman, J P
EM: jnaiman@physics.ucsc.edu
AF: UC Santa Cruz Astronomy & Astrophysics, 1156 High ST, Santa Cruz, CA 95064, United States
AU: * Naiman, J P
EM: jnaiman@physics.ucsc.edu
AF: University of of California, Santa Cruz, Physics Department, 1156 High ST, Santa Cruz, CA 95064, United States
AU: Smith, D M
EM: dsmith@scipp.ucsc.edu
AF: University of of California, Santa Cruz, Physics Department, 1156 High ST, Santa Cruz, CA 95064, United States
AU: Murphy, R J
EM: murphy@ssd5.nrl.navy.mil
AF: E.O. Hulburt Center for Space Research, Naval Research Laboratory, 4555 Overlook Ave. S.W., Washington, DC 20375, United States
AU: Share, G H
EM: share@ssd5.nrl.navy.mil
AF: Department of Astronomy, University of Maryland, College Park, MD 20742, United States
AU: Shih, A Y
EM: ayshih@ssl.berkeley.edu
AF: University of California, Berkeley, Space Sciences Lab, 7 Gauss Way, Berkeley, CA 94720, United States
AU: Kiener, J
EM: kiener@csnsm.in2p3.fr
AF: CSNSM, IN2P3-CNRS and Universite Paris-Sud, F-91405, Orsay Cedex, 91400, France
AB: We use the RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) to study solar flare gamma rays that are signatures of the accelerated ions. Specifically, we analyze the prominent 2.2 MeV line due to neutron capture whose time profile depends on the ambient 3He/H ratio, accelerated ion spectral index and incident ion angular distribution. For the first time we fit the 2.2 MeV time profile jointly with a full spectral fit to find a minimum in the total chi-square. This allows for self-consistent constraints on many of the flaring environment parameters, including the energetic particle spectral index, degree of pitch angle scattering, ambient abundances including 3He, accelerated abundances, magnetic field convergence, and the effective angle of the flare. The temporal model consists of a kernel (the response to a delta-function particle injection) convolved with the observed 4-7MeV flux, dominated by prompt nuclear emission. The spectral fitting includes a recently improved model of the nuclear de-excitation continuum.
DE: 7514 Energetic particles (2114)
DE: 7519 Flares
DE: 7554 X-rays, gamma rays, and neutrinos
DE: 7594 Instruments and techniques
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting