MODEL OF ION-INDUCED LUMINESCENCE BASED ON ENERGY DEPOSITION BY SECONDARY ELECTRONS

A model is proposed to describe the production of light induced by ene rgetic ions in scintillator materials, based on the distribution of en ergy deposited by the secondary electrons produced along the ion's tra ck. The initial energy of the electrons is determined using an impulse approximation in which their motion is constrained to the radial dire ction, perpendicular to the ion's track. The residual energy of the el ectrons along the radial coordinate is obtained from an expression for the specific energy loss obtained from Lindhard's potential theory. C ontributions from backscattered electrons to the energy deposition are included in the calculation. Local production of energy carriers is a ssumed to be proportional to the local density of deposited energy, in the absence of quenching effects. The latter are introduced by assumi ng the existence of a maximum energy density greater than which prompt quenching predominates and the energy carrier density reaches a maxim um constant value. Light production is related to the process of energ y transport through thermal diffusion of energy carriers to luminescen ce centers. Simple algebraic expressions are given for the energy depo sition profile and for the specific luminescence. Model predictions ar e compared with published experimental data from various organic and i norganic scintillators.