Pages: 193-200

Authors: Abid Hussain, Sikander M. Mirza, Nasir M. Mirza, Muhammad T. Siddique

Abstract

GEANT4 based Monte Carlo simulations have been carried out for the determination of effi -
ciency and conversion factors of a gas-flow ionization chamber for beta particles emitted by
86 different radioisotopes covering the average-β energy range of 5.69 keV-2.061 MeV. Good
agreements were found between the GEANT4 predicted values and corresponding experi -
mental data, as well as with EGS4 based calculations. For the reported set of β-emitters, the
values of the conversion factor have been established in the range of 0.5·10¹³-2.5·10¹³
Bqcm^-3/A. The computed xenon-to-air conversion factor ratios have attained the minimum
value of 0.2 in the range of 0.1-1 MeV. As the radius and/or volume of the ion chamber in -
creases, conversion factors approach a flat energy response. These simulations show a small,
but significant dependence of ionization efficiency on the type of wall material.

 

 

Key words: ionization chamber, gas-flow, efficiency, GEANT4 simulations

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