Results of recent code comparisons

The results of a recent international ''blind intercomparison'', that is a comparison of nuclear model calculations with each other and with experimental results unknown at the time of the calculations, are presented and discussed. Participants from 7 laboratories calculated the secondary neutron energy and angular distribution from the interaction of 25.7 MeV neutrons with the nucleus 184W, before these measured double-differential neutron emission cross-sections were made available. The comparison demonstrates that these models can reasonably describe the neutron energy spectrum except for the highest energy part, where an additional contribution from direct excitation of collective levels is definitely needed. The angular distributions can at present only be described adequately by phenomenological and semi-phenomenological methods. In addition some questions connected with the 1984 preequilibrium code intercomparison on 93Nb are reexamined. Especially the description of the neutron emission spectra at 14 and 25 MeV and the total proton emission cross-sections at 14 MeV are discussed in comparison with new measurements. It is pointed out that the spread in the reported total proton emission cross-sections needs further investigation