A method to determine spins, I, associated with transitions in superdeformed rotational bands in the mass 190 region is described and analyzed for conditions of validity. It contributed significantly to two recent articles proposing the relevance of pseudospin to some of these bands. An expansion of dI/dω in even powers of the rotational frequency, ω, is fitted, and its extrapolation down to ω=0 is integrated to obtain I. Typical errors for data with smaller backgrounds are 0.05ħ to 0.1ħ. A related method employing directly an expansion of the spins in odd powers of ω is briefly compared to this method. The dI/dω method has advantages for the crucial task of assessing the fit in the extrapolation region.

• Received 18 May 1990

DOI:https://doi.org/10.1103/PhysRevC.42.R1791