Basic Considerations on the Formation of a Sum Peak

A description of some basic considerations on the formation of a sum peak in a detector of cylindrical type may be useful. When a point source and a cylindrical detector are jdacol as in the geometrical arrangement in Fig. 20, the sum peak intensity ratio is given by the following relation 

W(0) can be calculated for the case in which enters the detector along the central axis and y enters the same detector at an angle 0 to the direction of yj  

Recently, Kudo et al. proposed that when the time differential PAG function W(0, t) is taken into account, the observed sum peak intensity is approximately expressed as follows  

The single peak counting rates Ij and h approximately expressed as  

SiiK the observed sum peak intensity always contains the contribution from accidental coincidence of two different nuclei emitting cascade y rays, the evaluation of the sum peak ratios should be carried out aa ording to the following relations  

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