The response of a NE102 scintillator to passing-through relativistic heavy ions

The response of a NE102 scintillator to He, C, Ne, Si and Ar ions has been studied at incident energies from 120 MeV up to 18 GeV when used as a transmission (ΔE) counter. The energy of the incident beam was changed by inserting an absorber of various thicknesses made of PMMA plates. The primary particles were identified and separated from projectile fragments by using the ΔE–E counter telescope method. A thin NE102 plastic scintillator and a BGO scintillator were used as a ΔE counter and a residual E counter, respectively. The energy of the primary particles was deduced by comparing the depth-dose distribution measured by an ionization chamber to those by a theoretical calculation. The light output of the NE102, dL/dx, was found to be linear to dE/dx in the low-dE/dx region, while gradually being quenched in the high-dE/dx region. This quenching was regarded as being a phenomenon independent of the particle species. The residual particle-species dependency was well indexed as a function of log (AZ2).