mixed radiation NSRL Solar Particle Event Simulation The NSRL SPE simulatoris based on the fluence of the August 1972 event, with an energy spectrum similar to the March 1989 event. The majority of the protons are at very low energies, below 1 MeV, and pose little to no risk to astronauts in a space craft or space suit. The SPESim begins with 50 MeV protons, which amounts to 91.66% of the total dose. Then the beam energy increments in steps of 10 MeV up to 150 MeV where 0.14% of the total dose is delivered. NSRL SPESim The samples were irradiated using the NSRL Solar Particle Event Simulation. NSRL SPESim