Gamma-gamma directional correlations and coincidence studies in154Gd

Abstract

The intensities, placements andE2/M1 mixing ratios of transitions in the decay of154Eu have been carefully studied to provide accurate data for microscopic calculations. Coincidence relationships in the decay of154Eu have been studied extensively with a multiparameterγ-γ coincidence system with two large volume Ge(Li) detectors. Spectra in coincidence with twenty energy gates were analyzed. Twenty-nine new coincidence relationships were established and confirmed most, but not all, of several levels previously assigned by energy fits only. From an analysis of coincidence spectra and singles spectra with a 18% efficiency Ge(Li) detector new information on the gamma-ray intensities were obtained. Precise values of theE2/M1 mixing ratios of transitions from the gamma- and beta-vibrational bands to the g.s. band have been determined fromγ-γ directional correlation measurements with a NaI(Tl)-Ge(Li) detector coincidence system. Mixing ratios were obtained for a number of other transitions including those fromKπ =0− and 2+ bands from direct and skipped cascade correlations.