Relating ionization quenching in organic plastic scintillators to basic material properties by modelling excitation density transport and amorphous track structure during proton irradiation.

Relating ionization quenching in organic plastic scintillators to basic material properties by modelling excitation density transport and amorphous track structure during proton irradiation.
Phys Med Biol. 2018 Sep 05;:
Authors: Christensen JB, Andersen CE
Abstract
Ionization quenching in organic scintillators is usually corrected with methods that require careful assessment of the response relative to that of an ionization chamber. Here, we present a framework to compute ionization quenching correction factors (QCFs) from first principles for organic plastic scintillators exposed to ions. The tool solves the kinetic Blanc equation, of which the Birks model is a simplified solution, based on amorphous track structures models. As a consequence, ionization quenching correction factors can be calculated relying only on standard, tabulated scintillator material properties such as the density, light yield, and decay time.
 The tool is validated against experimentally obtained QCFs for two different organic plastic scintillators irradiated with protons with linear energy transfers (LETs) between 5 and 70 MeV/cm. The QCFs computed from amorphous track structure models and the BC-400 scintillator properties deviate less than 3 % from the Birks model for LETs below 45 MeV/cm and less than 5 % for higher LETs. The agreement between experiments and the software for the BCF-12 scintillator is within 2 % for LETs below 45 MeV/cm and withi...

Source: Physics in Medicine and Biology - September 5, 2018 Category: Physics Authors: Christensen JB, Andersen CE Tags: Phys Med Biol Source Type: research