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 60Co
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 57Co,
88Y, and 134Cs 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 57Co, 88Y, and 134Cs, respectively.
The determination of correction factors for free-air ionization chamber calculation using monte carlo method
