Simultaneous measurement of prompt neutrons and fission fragments for (PU)-P-239(n(th), f)

The multiplicity and energy of the prompt neutrons emitted from the fission fragments for Pu-239(n(th), f) were measured as functions of the fragment mass and total kinetic energy. The results were compared with those for U-2 33(n(th), f) and with the predicted values by the multi-channel fission the ory with the random neck rupture model. The measured and predicted values of the neutron multiplicity, [nu](m*), sh ow the saw-tooth trend and agree with each other. The total neutron multipl icity decreases linearly with increasing total kinetic energy resulting in - d(TKE)/d[nu (tot)]=16.5+/-0.4 MeV/neutron. The slope of the neutron multi plicity vs, the total kinetic energy, -d[nu ]d[TKE], was plotted against th e fragment mass. Its shape agrees with that for U-233(n(th), f). The average neutron emission energy, [eta](m*), follows a bell shape about the symmetric fission accompanying higher values for very asymmetric fissio ns and agrees with that for U-233(n(th), f). The total excitation energy [T XE](m*) was determined by two manners: (1) neutron data and (2) Q(max)-[TKE ]. Both results satisfactorily agree with each other as the case of U-233(n (th), f), and thereby the present derivation of [TKE] from the neutron data is confirmed.