CONTRIBUTION OF LOW-ENERGY PROTONS TO THE DEGRADATION OF SHIELDED GAAS SOLAR-CELLS IN SPACE

The cumulative fi action of the displacement damage dose deposited in shielded GaAs solar cells in typical space proton environments is pres ented as a function of energy from the threshold for atomic displaceme nt up to 400 MeV, Results ave presented for silica coverglass thicknes ses from 3-30 mils, and for both slowed down and incident proton energ ies, As an example, it is found that for cells shielded by 30 mils of coverglass in a circular 5000 km orbit, less than 15% of the degradati on is caused by protons with slowed down energies < 0.1 Me V, whereas similar to 50% of the total degradation is produced by protons in the energy range I < E < 10 MeV, (C) 1997 John Wiley & Sons, Ltd.