Cross Sections of ^(109)Ag(n,2n)^(108)Ag^m,^(151)Eu(n,2n)^(150)Eu^m,^(159)Tb(n,2n)^(158)Tb and ^(179)Hf(n,2n) ^(178)Hfm^2 Reactions

The cross sections for the formation of long-lived products 108Agm（6+,433a）,150Eum（5-,36.9a）,158Tb（3-,180a）and 178Hfm2（16+,31a）are measured in the（n,2n）reaction on the elementsof 109Ag,151Eu,159Tb and 79Hf at neutron energies of 9.5 MeV and 0.9 MeV,respectively.The neu-tron fluence is obtained through the 197Au（n,2n）196Au reaction.The D（d,n）3He reaction is used as neu-tron source at the tandem accelerator.The present results are compared with the averaged values of theo-retical cross sections and the experimental data.