Simulation and Optimization for Space Low Energy Charged Particle Detector

In order to measure electron and proton in space with the range of 0.1~1.0MeV , a permanent magnet and two pieces of one dimension position-sensitive silicon micro-strip detectors(PSSMSD) are used. When incident through the aperture of the detector, the proton will be gathered by a PSSMSD denoted D1 which is paralleled to the center line of the aperture. The distance between D1 and the center line of the aperture is 5mm. while, electron will be gathered by another PSSMSD denoted D2 after deflected to 180 degree. Measure the distance between the center line of the aperture and the point on the PSSMSD which the particle hit, the energy of the particle could be calculated. Based on Geant4, the detector is modeled; The energy resolution, the error in energy measurement and the discrimination efficiency between proton and other positive ion are simulated. The optimized results for the two PSSMSDs are given.