Channel effect in isomeric ratio of .sup.137m,gCe produced in different nuclear reactions

This work presents the experimental study of the isomeric ratio of .sup.137mCe-.sup.137gCe produced in .sup.138Ce([gamma], n) .sup.137m,gCe photonuclear reaction, in neutron capture reaction .sup.136Ce(n, [gamma]) .sup.137m,gCe and in the two simultaneous reactions .sup.138Ce([gamma], n) .sup.137m,gCe and .sup.136Ce(n, [gamma]) .sup.137m,gCe in the mixed photon-neutron field by the activation method. The investigated samples were irradiated at the bremsstrahlung photon flux, in the epithermal and thermal-epithermal neutron beam and in the mixed photon-neutron field constructed at the electron accelerator Microtron MT-25 of the Flerov Laboratory of Nuclear Reaction, Joint Institute for Nuclear Research, Dubna, Russia. The results were analyzed, discussed and compared with those of other authors to examine the role of the channel effect in nuclear reaction and provide the nuclear data for theoretical model interpretation of nuclear reactions.