Fission-product spectrometer


The main observables in thermal-neutron-induced fission are fission yield, as a function of nuclear charge Z and atomic mass A, and the kinetic energy of the fragments.

At PN1, an almost complete survey has been performed of fission yield for many fissile systems, ranging from 229Th to 251Cf and passing by the well-known actinides 233U, 235U and 239Pu, which are important in nuclear reactors.

The systematic investigation of fission yield has revealed important insights into the process: apart from the known double-humped gross structure, a pronounced fine structure in the fission-yield curve was found. This fine structure could be traced back to the persistence of proton pairing in fission, even at higher excitation energies.