The spin of the 2,198 keV level in74Ge and multipole mixing ratios of gamma transitions in the decay of74As

Abstract

Abstract. Directional-correlation measurements of several cascades in the 74As decay have been made with a NaI-Ge(Li) detectors system. In the 74Ge the following cascades were measured: 608-596 keV, 994-1,204keV, 994-(608)-596 keV and 887-596 keV. The corresponding results give a unique spin assignment of 2 for the 2,198 keV level and determine the E2/M1 mixing ratios of ~(608)=3.4+0.4 and 6(994)=-(2.8+0.2). In the ~4Se it was measured the 635-635 keV cascade. The result obtained assigned the spin of the 1,270keV level as 2 and fixed the E2/M1 mixing ratio of 6(635)=-(2.6+0.2). Also a 3,-intensity study has been made to determine the branching ratios of the transitions that deexcite the 1,270keV level in 74Se. From these data a I(635)/I(1,270)= 12.5_+5.0 is obtained.