BEXCO - Room F(201/202/203/204)
[SH082] Solar Neutron Telescope Count Peaks Not Due to Gamma Rays
Muraki et al. (2013) present the 7 March 2011 count history of the solar neutron telescope (SNT) at Mt. Sierra Negra showing two peaks of equal intensity one hour apart. They give several reasons for a peak to be due to solar gamma rays and not neutrons. One reason is the Fermi satellite detected solar gamma rays that day over Earth. They conclude high energy solar gamma rays must be the cause, and they are the first to have experimental data of solar gamma rays reaching the ground. They overlooked the significant result, that solar gamma rays must have exposed aircraft flying at low latitudes. But, the first solar gamma ray count peak at Fermi did not begin until after the first SNT count peak, and the maximum flux at Fermi was less than the SNT peak count rates. Further, the second SNT peak occurred when the Sun was closer to the SNT at Mt. Mauna Kea, and that SNT did not register any count peaks. Weather data rule out thunderstorms as causing counts, and the SNT energy threshold excludes radioactivity. In conclusion, the SNT peaks were not due to radiation, solar gamma rays were not counted at the ground, and there is no proof they reached flight levels.