Application of transient magnetic fields to the measurement of g-factors for shortlived nuclear states populated by multiple Coulomb excitation

Abstract

Procedures are described for determining g-factors of shortlived states in strongly deformed nuclei using the recently discovered intense transient magnetic fields which are experienced by fast recoils slowing down in ferromagnetics. The high spin states are populated instantaneously by multiple Coulomb excitation with very heavy ions whose backscatter trajectories are selected by an annular particle detector. A computer program is described that evaluates the time evolutions of level populations and spin precession angles as the excited ions slow down in the ferromagnetics. The time-integral variations in the yields of deexcitation γ rays are computed in cases where the precession angles are the result either of subsequent transient and static fields (i.e., the recoils stop in the ferromagnetics), or of transient fields only (i.e., the recoils stop in a non-ferrous environment). The important features of the method are illustrated by several examples and, in a few cases, by comparisons with experimental data. The corrections caused by the bending of incident and scattered beam particles in the applied polarizing field are evaluated in an appendix.