Solar Neutron and Gamma-ray Monitor for a Small Satellite
K. Yamaoka, for the ChubuSat-2 collaboration
Solar neutrons can be probles for clarifying the ion acceleration mechansm in the Sun. However, there are only a few 10
detections up to present. The SEDA-AP Fiber detctor on the International Space Station (ISS) has been currently observing solar neutrons
from space. In order to proceed solar-flare studies, we have developed very compact solar neutron and gamma-ray monitor
for the micro satellite ChubuSat-2 utilizing the multi-pixel photon counter (MPPC) as a readout of scintillators.
The realized size of the detector is 15 cm$\times$17 cm$\times$18.5 cm and its weight is 6.2 kg.
We launched it on February 2016, but the detector has not been turned on yet due to a trouble in the satellite bus system.
To upgrade the detector, we will use an ASIC instead of discrete electric parts for MPPC readout to reduce the
electric power and space. In this paper, we will describe
details of solar neutron detectors on the ChubuSat-2 and a future satellite.