Investigation of the Dependence of CsI(Tl) Scintillation Time Constants and Intensities on Particle's Energy, Charge and Mass Through Direct Fitting of Digitized Waveforms

Abstract

The dependence of the CsI(Tl) scintillation time constants and intensities on the particle ionization profile is at the basis of the Charge and Mass identification technique for Light Charged Products in Intermediate Energy Nuclear Physics multi-detector arrays. The possibility of storing the digitized waveforms in true beam experiments allows performing further offline analyses and makes available a data set related to the interaction of different particle types in a wide energy range.We propose the direct least-square fitting of the baseline subtracted output waveforms as a method for the determination of the four-vector defining the CsI(Tl) scintillator light output as a function of the particle energy, mass and charge. In the present work we investigate the dependence of the four-vector on the energy deposited in the CsI(Tl) crystal in the range 10 MeV-240 MeV for isotopes with and also for ions with -with no isotopic dependence-through the analysis of the waveform data set . This work was supported by INFN (Istituto Nazionale di Fisica Nucleare) in the framework of the EXOCHIM experiment and partly by the MIUR (Ministero dell'Universita' e della Ricerca Scientifica) program PRIN2009 "Studio e realizzazione del prototipo di un sistema di rivelazione ad alta risoluzione angolare per la misura con alta precisione dell'impulso di particelle leggere e di frammenti, da utilizzare per studi di dinamica e spettroscopia in reazioni nucleari con fasci stabili e radioattivi ad energie basse ed intermedie," protocol 2009RLCYL8.

Hadronic vs. electromagnetic pulse shape discrimination in CsI(Tl) for high energy physics experiments

“…Using this model, the pulse shapes for CsI(Tl) are characterized by the parameter N Hadron defined as the scintillation emission intensity of the hadron scintillation component. This single parameter pulse shape description is advantageous compared to present approaches for pulse shape characterizing techniques for CsI(Tl) where the four shape parameters (τ fast ,τ slow , N fast and N slow ) of the two component scintillation model are varied to describe the CsI(Tl) pulse shape spectrum as done in references [2] and [20]. In addition these studies have shown that low energy hadron energy deposits, which result in the largest pulse shape difference from photons, will result in fast time constants in the range of approximately 600-650 ns when fit to the two component model [20].…”

“…This single parameter pulse shape description is advantageous compared to present approaches for pulse shape characterizing techniques for CsI(Tl) where the four shape parameters (τ fast ,τ slow , N fast and N slow ) of the two component scintillation model are varied to describe the CsI(Tl) pulse shape spectrum as done in references [2] and [20]. In addition these studies have shown that low energy hadron energy deposits, which result in the largest pulse shape difference from photons, will result in fast time constants in the range of approximately 600-650 ns when fit to the two component model [20]. This is in agreement with our model where it is expected that the τ Hadron component would dominate the scintillation emission for these pulses and thus a pulse shape description using a two component scintillation model is expected to produce a fast time constant consistent with our hadron time constant.…”

Experimental investigation of α condensation in light nuclei

“…To determine the energy of the particle where ∆E-E PID was possible, this value was calculated via the signal in the silicon stage due to the non-linear response of the CsI(Tl) crystal as well as its mass and charge signal dependence [29]. This gives an energy resolution of approximately 400 keV for a 30 MeV α-particle increasingly approximately linearly to 1000 keV for a 60 MeV α-particle.…”

Trends in particle and nuclei identification techniques in nuclear physics experiments

“…The same method is used with CsI(Tl) scintillators of the FARCOS array. Recently, also a digital electronics (GET) can be used, that allows the digitization of the total shape of signals [158,159].…”