A GRAPHICAL ANALYSIS OF DECAY CURVES MEASURED BY THE DOPPLER-SHIFT RECOIL DISTANCE METHOD

The present method of analyzing the decay curves is a direct extension of the method of linearizing an exponential decay using a semilog plo t. On semilog graph paper experimental points of a decay curve can be approximated using a smooth curve having a slowly varying slope with r ecoil distance. In addition, the lifetime of an excited state can be e xpressed as the product of two factors: the reciprocal of the slope of a semilog graph and a correction factor for feeding time. These facto rs can be evaluated from two semilog graphs for the successive transit ions, feeding and de-exciting a given excited state. This factorizatio n simplifies the analysis of the decay curves and brings the method a considerable tolerance as regards their experimental errors. The prese nt method has been applied to the decay curves measured in Ce-124,Ce-1 26 and Nd-132,Nd-134.