A new technique for measuring g factors of excited states in fission fragments using large arrays of Ge detectors

The theory behind a new, three-dimensional analysis technique for the measurement of time-integral, perturbed angular correlation (IPAC) functions is presented. The new technique is described in relation to existing methods and in terms of its specific application to a large, Ge-detector array. The effective application of the new technique is demonstrated with results from an experiment where the g factors of excited states in Cf-252, secondary fission fragments were determined. A Cf-252 source, sandwiched between two iron foils and placed in a saturated magnetic field at the centre of the Gammasphere detector array, was used to make IPAC measurements of prompt gamma rays in order to deduce Larmor precession angles of stopped fragments in iron. The g factor of the I-pi = 2(+) state in (MO)-M-104 was thus measured to be g = +0.248(22). This new measurement shows a factor-of-5 improvement to the precision which has previously been attained in more conventional experiments.