New structure information on Mg-30, Mg-31 and Mg-32

Abstract

The fast timing βγγ(t) method was applied to investigate the level lifetimes in 30,31,32Mg. Levels in Mg have been populated in β and β-delayed neutron emission of Na, at the ISOLDE facility. From the γγ coincidences a number of new states have been identified and new level schemes were constructed for 30 31,32Mg. The following preliminary half lives have been determined: T-1/2 = 3.9(4) ns for the 1789 keV state in 30Mg, T-1/2 = 133(8) ps and 10.5(8) ns for the 221 keV and 461 keV states in 31Mg, respectively, and T-1/2 = 16(4) ps for the 885 keV level in 32Mg. The 1789 keV level was established as a candidate for the intruder 0(+) configuration in 30Mg with a possible strong E0 branch to the ground state.