Radiation stability of SiO2 micro- and nanopowders under electron and proton exposure

The effects of proton and electron ( E   =   100   keV, F   =   5   ×   10 15   сm −2 ) exposure on the reflective spectra of SiO 2 micro- and nanopowders in wavelength range from 250 to 2500   nm have been investigated. It has been established that the reflectance and radiation stability of nanopowders is less than that of micropowders. This effect is caused by the high concentration of radiation defects, which act as surface absorption centers ( E s ′ centers) near the energies 5.47 and 4.45   eV, and peroxide silicon defects ( Si O O Si ) near the energy 3.84   eV.