Nuclear Technology & Radiation Protection: Year 2014, Vol. 29, Suppl., pp. S8-S13

DOI:10.2298/NTRP140S0S8C

# Determination of True Coincidence Correction factors using Monte-Carlo simulation techniques

Aim of this work is the numerical calculation of the true
coincidence correction factors by means of Monte-Carlo simulation
techniques. For this purpose, the Monte Carlo computer code PENELOPE
was used and the main program PENMAIN was properly modified in order
to include the effect of the true coincidence phenomenon. The modified
main program that takes into consideration the true coincidence
phenomenon was used for the full energy peak efficiency determination
of an XtRa Ge detector with relative efficiency 104% and the results
obtained for the 1173 keV and 1332 keV photons of ^{60}Co
were found consistent with respective experimental ones. The true coincidence correction factors
were calculated as the ratio of the full energy peak efficiencies was
determined from the original main program PENMAIN and the modified
main program PENMAIN. The developed technique was applied for
^{57}Co, ^{88}Y, and ^{134}Cs and for
two source-to-detector geometries. The results obtained were compared
with true coincidence correction factors calculated from the "TrueCoinc"
program and the relative bias was found to be less than 2%, 4%, and 8% for
^{57}Co, ^{88}Y, and ^{134}Cs, respectively.