First g factor measurement using a radioactive 76Kr beam

Abstract

The g factor of the first 2+ state of radioactive 76Kr (T1/2=14.8 h) has been measured, extending the systematics of the previously measured stable 78,80,82,84,86Kr isotopes. The measurement was performed with a radioactive 76Kr ion beam applying projectile Coulomb excitation in inverse kinematics combined with the transient magnetic field technique. The 76Kr beam was produced and accelerated in batch mode (re-cyclotron method) at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. A total of three production and acceleration cycles yielded six hours of beam on target with peak rates of 108 particles/s. About 5.6×104 particle-γ coincidence events were recorded. The g factor g(76Kr;2+1)=+0.37(11) was obtained by direct comparison to the known g(78Kr;2+1) value re-measured immediately after the 76Kr runs with the same setup and under almost identical kinematic conditions.