ION-BEAM INDUCED LUMINESCENCE IN FUSED-SILICA

A luminescence band at 450 nm (2. 7 ev) is observed during ion irradiation of fused silica at energies between 0. 7 and 2. 0 Mev. The intensity is a function of dose and ion species. The energy deposition required to produce maximum signal is of the same order as that reported for other saturable damage parameters in silica (such as the compaction associated with bond reorientation, and changes in the refractive index). The damage model proposed to explain the compaction results is discussed and is adapted for the purposes of incorporating the present data by suggesting that the luminescence sites are primarily formed by the energy deposited from nuclear collisions, (dE/dx)//n, whereas the excitation of the luminescence is determined by the instantaneous electronic energy losses, (dE/dx)//e//l, from the ion beam. Thus the intensity of the luminescence signal results from a convolution of the time integral of the (dE/dx)//n curve and the (dE/dx)//e//l profile.