Physico-chemical changes in ion-irradiated KDP

We report on Mev He+ ion-induced physico-chemical changes brought into single crystalline potassium dihydrogen phosphate (KDP). Fluence-dependent hydrogen concentration has been studied by on-line elastic recoil detection analysis technique at different temperatures. Room temperature measurements show significant hydrogen loss from the samples, while at low temperature, there is no loss of H (at low fluences) or a little loss (at higher fluences). Structural changes studied by micro-Raman measurements also confirm loss of H followed by amorphization of KDP. Hydrogen depletion from KDP has been addressed in terms of basic ion-solid interaction. A phenomenological model has been used which considers ion-induced bond-breaking, diffusion of H radical, formation of H2 molecules and its release