An experimental comparison of simple peak area determination methods in gamma spectroscopy

The statistical accuracy and the consistency under varying levels of background intensity are experimentally compared for six simple methods of peak area integration. Partial peak area methods (PPA) of the Wasson type yield better statistical accuracy under fixed conditions than methods based on total peak area determination (TPA), but display a negative bias with increasing background intensity. A new partial peak area determination method based on variable summing width, continuous monitoring of FWHM and linear interpolation between channels is proposed and tested. The proposed method compares favourably with established methods, combining the good statistical accuracy of PPA methods with the consistency of TPA methods. The experimental results indicate that theoretical error estimates based on simple Poisson statistics are inadequate.