Radiation shielding study of Advanced Data and Power Management Systems (ADPMS) housing using Geant4

A design goal for current space system is to reduce the mass used to enclose components of the spacecraft. One potential target is to reduce the mass of electronics and its housings. The use of composite materials, especially CFRP (Carbon Fiber Reinforced Plastic) is a well known and vastly used approach to mass reduction. A design goal, cost reduction, has increased the use of commercial (non-space qualified) electronics. These commercial circuits and other components cannot tolerate as high radiation levels as space qualified components. Therefore, the use of standard electronics components poses a challenge in terms of the radiation protection capability of the ADPMS housings. The main goal of this study is to provide insight on the radiation shielding protection produced by different configurations of CFRP tungsten laminates of epoxies and cyanate esters and then to compare them to the protection given by the commonly used aluminum. For a spacecraft operating in LEO and MEO orbits the main components of the space radiation environment are energetic electrons and protons, therefore in our study we will compare the experimental and simulation results of the radiation attenuation of different types of laminates for those particles. At the same time the experimental data has been used to validate the Geant4 model of the laminates, which can be used for future optimizations of the laminate structures. Index Terms--Advanced equipment design, carbon composite laminates, GEANT4, LEO and MEO orbits, low Z-high Z-low Z concept, radiation attenuation, shielding.