The mean-square angular momenta of the compound nucleus ${}_{}{}^{227}{}_{}{}^{}\mathrm{Pa}$ becomes constant at and below the energy which shifted F MeV from barrier ${\mathit{V}}_{\mathit{b}}$ with respect to one-dimensional barrier penetration. This energy shift is borne out to be self-consistent with the total coupling strength extracted from the 〈${\mathit{l}}^2$〉 value at the barrier.

• Received 25 July 1990

DOI:https://doi.org/10.1103/PhysRevC.42.2752