Progress in Studying Scintillator Proportionality: Phenomenological Model

Abstract

Abstract-We present a model to describe the origin of nonproportional dependence of scintillator light yield on the energy of an ionizing particle. The non-proportionality is discussed in terms of energy relaxation channels and their linear and non linear dependences on the deposited energy. In this approach, the scintillation response is described as a function of the deposited energy deposition and the kinetic rates of each relaxation channel. This mathematical framework allows both a qualitative interpretation and a quantitative fitting representation of scintillation non-proportionality response as function of kinetic rates. This method was successfully applied to thallium doped sodium iodide measured with SLYNCI, a new facility using the Compton coincidence technique. Finally, attention is given to the physical meaning of the dominant relaxation channels, and to the potential causes responsible for the scintillation nonproportionality. We find that thallium doped sodium iodide behaves as if non-proportionality is due to competition between radiative recombinations and non-radiative Auger processes.

Scintillation mechanisms of inorganic materials: From crystal characteristics to scintillation properties

“…By simulating the track creation, recent studies confirm this hypothesis and give a deeper understanding of the process [10,11]. The main causes of energy loss are the nonradiative Auger de-excitation (i.e.…”

Development of transparent ceramic Ce-doped gadolinium garnet gamma spectrometers

“…The Scintillator Light Yield Non-proportionality Characterization Instrument (SLYNCI) [12][13][14] provides valuable feedback to compare various garnet structures and identify the best ceramics processing methods. We have studied a range of garnets formed by different methods to determine their impact on light yield proportionality.…”

“…It is well-known that the light output of scintillators is not rigorously proportional to the amount of energy deposited in the scintillator [12][13][14], and that scintillator energy resolution is poorer than that predicted by the photon statistics of the deposited energy. Figure 8 and Table I show the SLYNCI measurements acquired with several Ce-doped garnet transparent ceramics and single crystals.…”

Simple model relating recombination rates and non‐proportional light yield in scintillators

“…[9 -14]. The curve with f x = 0 represents the local profile qualitatively similar to the light yield of NaI:Tl vsdE/dx due to Meyer and Murray [6] and more recent results of SLYNCI experiments [12]. The important features reproduced in the model curve are the characteristic rising slope at small dE/dx and the falling slope at large dE/dx.…”