The influence of peak area determination bias in quantitative gamma-ray spectrometry in the presence of true coincidence summing

It is sometimes stated that a gamma-ray spectrum analysis program need not produce absolute peak area estimates as long as the program is consistent and the area estimate is indeed proportional to the true peak area. In this paper, it is demonstrated both theoretically and experimentally that this is not true in the presence of true coincidence summing. The experiment described provides a method to test the correctness of peak areas determined by any method. An alternative, simpler method is also proposed. It is concluded that the ANSI N42.14-1991 standard is incomplete in this respect. The results are relevant to gamma-ray spectrometry with either semiconductor or scintillation detectors.