Resolution of the nature of the coupling in subthreshold fission in STYU+n

The analysis of a recent high-resolution neutron capture measurement at 152 m has provided the first evidence that the strong fission resonance at 721 eV is a class-II resonance. This conclusion is based on the measured capture width of 4.7 +- 0.6 MeV, which is considerably smaller than the average capture width of 23.5 MeV for the neighboring resonances. Furthermore, after analyzing the fission widths for the 721- and 1211-eV clusters, we conclude for the J/sup / = 1/2 fission barrier in STZU that the inner barrier is lower than the outer barrier by approx.1.5 MeV.