Authors: Darius Desnoes (University of New Hampshire), James Ryan (University of New Hampshire)

Gamma rays and neutrons play an important role in the study of solar flare activity from the Sun. Their neutral charge helps retain information of their emission from the Sun, such as implications of proton and alpha particle acceleration, or the creation and decay of neutral and charged pions. The Solar Neutron TRACking (SONTRAC) instrument (under development) will simultaneously measure gamma ray and neutron emission from the Sun using organic scintillators and silicon photomultipliers (SiPMs). It has a high S/N ratio because it requires an incident neutron to scatter in a fashion consistent with the solar direction.  However, modifications to SONTRAC are being considered to better assess the instrument’s capability to measure gamma rays above 10 MeV. This requires a high-Z converter plate to convert the photons into electron-positron pairs that can be measured and imaged in the scintillator array tracker. The high-Z material will increase the detection of solar gamma rays above 10 MeV due to the easier and unique signature of a pair in the tracker. While beneficial, the converter plate has adverse effects, such as background cosmic rays producing neutrons that can be confused with solar neutrons.  The instrument may be unable to differentiate between neutrons produced in the converter and incident solar neutrons. We are studying the pros and cons of the converter plate by simulating protons and gamma rays of varying energies as they interact with the converter plate of variable thicknesses and compositions. The goal is to find a converter plate that simultaneously increases gamma ray detection without significant secondary neutron production and detection. Future work includes running simulations with a veto panel to negate the detection of secondary neutrons that had a subsequent proton produced alongside it as they travel towards the scintillators.