RPID - A new digital particle identification algorithm for CsI(Tl) scintillators

A new digital algorithm for online particle identification in CsI(Tl), called Reconstructive Particle IDentification (RPID) is reported. The concept is based on a model for the signal generation with two exponential components for the scintillation light output and an exponential response function of the preamplifier. To provide a fast algorithm which could be used online in modern FPGA-based electronics a simplified method for signal deconvolution was developed. Within a few simple processing steps the original pulse shape is modified to recover the amplitudes of the two scintillation components that determine the type of particle. Data from an experiment 12C (p,p') 12C* at 21 MeV allowed to separate γ -rays and protons even of very low energies. We present the performance of this new algorithm concerning the γ -proton separation as well as the identification of protons not fully stopped within the CsI(Tl). (orig.)