( n, 2 n) Anregungsfunktionen fürFe,Ge,Se,Rb,Sr,Y,Mo,Hg im Neutronenenergiebereich 13-18 MeV.

Using the activitation method ( n,2 n) excitation-functions were measured forFe,Ge,Se,Rb,Sr,Y,Mo, andHg in the neutron-energy region 13-18 MeV. The results are checked for consistency by means of a systematic of ( n, 2 n) cross-sections as a function of the nuclear neutron excess ( N-Z)/A. Furthermore the data are compared with results from the statistical nuclear reactions theory which were calculated using optical model absorption cross-sections and the Fermi-gas-model formula for the nuclear level density. In the case ofHg the influence of preequilibrium nucleon emission was taken into account. [ABSTRACT FROM AUTHOR]