PARAMAGNETIC CENTERS IN GLASSES INDUCED BY LOW-EARTH-ORBIT SPACE RADIATION

After having been exposed to space radiation on the experimental platf orm Eureca (European Retrievable Carrier) for almost eleven months, di fferent optical glasses were examined to determine radiation effects. For the 500 km high orbit with low inclination a radiation dose of 10( 3) Cy is assumed, Using electron paramagnetic resonance (EPR) spectros copy spectral components due to radiation effects were detected at roo m temperature. Oxygen hole centers (OHCs) were indicated in borosilica te glass, soda lime glass, phosphate crown glass, fluor crown glass an d lanthanum crown glass, Ti3+ was found in borosilicate glass. All inv estigated materials - excluding fused silica and fluoride glass - had differing intensities of Fe3+ components caused by iron impurities in the samples. Comparing these results to earth specimen used in a simul ation program, specially developed in preparation for the Eureca missi on, the same type of radiation induced defects were identified, This c onfirms the validity of the simulation program as an appropriate tool to predict the performance of glass materials before space missions.