Angular momentum dependence of 200Pb fission studied by comparison of 19F on 181Ta with 16O on 184W

Combining a langevin description of heavy-ion induced fission including neutron evaporation with the statistical model

“…In Fig. la we show the calculated fusion excitation function in comparison to the data extracted from [14,15]. In Fig.…”

“…We do so as this model is able to reproduce simultaneously the experimental fusion cross sections and spin distributions in a number of cases. In the following, we restrict our investigations to the 19F+ 181Ta system as a representative example, because for this system the energy dependence of fusion and fission properties has been measured by two independent groups [14,15]. In Fig.…”

“…1 b the parameters l~ and 61 are shown which fit the surface friction model calculation using the parametrization of the transmission coefficients of (1). In [14,15] are also entered in the -o figure Fig. lb the values for 31 used in [14,15] are entered which approach our calculated ones only at low or at high energies, respectively.…”

“…Because there is very conflicting information on the values for 6l in the literature [12][13][14][15], we do not parametrize the spin distribution by fitting some data but calculate it by a theoretical model. From the various models, which are for example reviewed in [16], we choose the surface friction model in the version of [6], which is an extension of the theory discussed in [7].…”

“…Because there is a rapid change in the fission probability in the angular momentum region where the fission barrier crosses the neutron binding energy, a sensitivity to the spin distribution of the fused system is expected. In the literature [12][13][14][15] the fusion cross section is often parametrized as(1)The quantity lc is sometimes obtained from a model and the diffuseness 61 is used as a fitting parameter. Because there is very conflicting information on the values for 6l in the literature [12-15], we do not parametrize the spin distribution by fitting some data but calculate it by a theoretical model.…”