Quadruple moment of the i13/2 intruder band in 139Gd

Abstract

The Doppler shift attenuation method has been used to extract the mean quadruple moment of the nu i13/2 intruder band in 139Gd. From a centroid-shift analysis of the data, and using Braune stopping powers, a value for the intrinsic nuclear quadrupole moment of Q0 approximately=7.0 eb is suggested, corresponding to a deformation beta 2 approximately=0.35. Because of appreciable side-feeding into the band at each level, a lineshape analysis of the data has also been attempted, in which the time structure of the side-feeding has been allowed to vary. This analysis indicates that the side-feeding is significantly slower than the in-band cascade.