The Decay of ⁹⁹Mo

Abstract

The decay of 67h ⁹⁹Mo to the levels of ⁹⁹Tc has been studied with Ge(Li), Ge and Si(Li) detectors. Some new gamma rays of energies of 38, 163.4, 319.8, 321.0, 352.9, 599.6, 727.07 and 1082.2 keV have been observed. One new level at 163.4 keV is suggested and two controversial levels at energies 726.7 and 1081.4 keV have been confirmed. The directional correlation system has been used to measure the 740–181, 740–(40)–140, 961–181 and 822–(40)–140 keV cascades. These measurements confirm 3/2⁺, 5/2⁻ and 1/2⁻ spin assignments for 921.0, 1004.2 and 1142.1 keV levels. The mixing ratios of 40.585, 140.511, 739.7, 823.1 and 961.0 keV gamma rays have been obtained as M1+≤6.25×10⁻²% E2, M1+9±1% E2, E2+8.0±1% M1, E1±1% M2 and M2+E2, respectively.