Fast scintillators as radiation resistant heavy-ion detectors

Three promising scintillation materials, namely GSO(Ce), YAP(Ce), and CsI (pure), were investigated under 50MeV 12C and 100MeV 32S heavy-ion irradiation. The radiation resistance, light output and time structure of the scintillation were measured. The measurements were complemented by studies of the transmittance and thermoluminescence of the irradiated crystals. GSO(Ce) and CsI(pure) show an excellent radiation resistance together with a high light output. Maintaining a time resolution in the nanosecond regime, their applicability for heavy-ion detection with accumulated doses up to 5 × 1013 ions/cm2 was demonstrated. This enables their continuous operation in counting applications with high average ion rates occurring, e.g., at heavy-ion storage rings. A CsI(pure) scintillation detector realized on the basis of these measurements for electron-ion recombination experiments at the Heidelberg heavy-ion storage ring TSR is described.