Proton Acceleration by Very Impulsive Flare on June 3, 2012
K. Kamiya, K. Koga, S. Masada, H. Matsumoto, Y. Muraki, T. Obara, O. Okudaira, Y. Tanaka, S. Shibata, T. Goka
On June 3, 2012, a very impulsive solar flare was observed by the GOES, RHESSI and FERMI- LAT satellites. The intensity of the flare was M3.3. The hard X-ray intensity (> 100 keV) rose ≥ 1000 times within one minute and then decayed immediately to the background level (in less than one minute). It was an extremely impulsive flare. By chance, the SEDA-FIB solar neutron detector onboard the International Space Station detected a 5.1σ enhancement due to solar neutrons. Therefore, it provided a good opportunity to investigate the mechanism of instantaneous proton acceleration to a few GeV. Based on the results of a new Monte Carlo calculation, we will show a reasonable proton acceleration model for the June 3, 2012 event. We also reexamined another very impulsive flare observed on June 10, 2010.