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

From a solar flare or CME event, neutrons and gamma rays from nuclear collisions and particle decay can travel from the Sun to the Earth. The SOlar Neutral TRACking (SONTRAC) instrument detects them simultaneously to better recreate how the radiation made it to Earth, and when it was emitted. However, neutral radiation from Earth or produced inside SONTRAC can diminish the signal strength of the incident solar neutral radiation. We first simulated basic energy depositions from local gamma rays (10-100 MeV) and neutrons (20 – 200 MeV) in an inorganic scintillator for 10,000 events, showing that as incident energy increased, the local neutral radiation decreased. Changing the converter plate thickness increased gamma ray pair production measurements, but after 1cm thickness it began to decrease. These simulations help determine the optimal SONTRAC parameters for balancing between minimizing local and amplifying solar neutral radiation. With parameters set, scintillated light from the inorganic scintillator is detected by Silicon PhotoMultipliers (SiPMs) to turn deposited energy into an electronic signal using a reverse-biased photodiode. Using well-documented radioactive isotopes to calibrate a multichannel analyzer (MCA) for a specific energy range, the incident energy of any incoming radiation is predictable. For future endeavors, we will increase the complexity of the simulations by including a tungsten converter plate, and by broadening the possible incident directions of the neutral radiation to mirror real life measurement issues.