Simulation of Beta Ray Spectra in Liquid Scintillation Counting System by means of Monte Carlo Method
Yi, Chul-Young;Jun, Jae-Shik;
ABSTRACT
Beta ray spectra of $^3H,;^{14}C;and;^{36}Cl$ in liquid scintillation counting system have been calculated using the Monte Carlo method by which physical behaviors of particle transport in medium were simulated. The calculations have been carried out on the basis of beta rays being slowing down according to the continuous slowing down approximation(CSDA) model. Beta rays generated in simulation geometry were traced until they lost their energy below 0.3keV that in known to be the detection limit in the liquid scintillation counter. Scintillator solution in which pure beta emitting radionuclides were dissolved uniformly was assumed to be bottled in the shape of right circular cylinder with 12.5mm in radius and 35mm in height. The comparison of the calculated and measured results showed satisfactory agreement between those two, with slight discrepancy due to self quenching in the case of lower energy of emitted beta particles in the solution.