Measurement of Fragment Mass Dependent Kinetic Energy and Neutron Multiplicity for Thermal Neutron Induced Fission of Plutonium-239
Kinetic energy and neutron multiplicity as a function of fragment mass were measured for the thermal neutron induced fission of <SUP>239</SUP>Pu. By measuring the velocities and energies of two fission fragments simultaneously, both of the pre-neutron emission fragment mass m<SUP>*</SUP> and the post-neutron mass m were obtained. The fragment mass dependent neutron multiplicity ν(m<SUP>*</SUP>)was deduced by subtracting m from m<SUP>*</SUP>. The fragment mass dependent total kinetic energy TKE(m<SUP>*</SUP>) was also obtained from this data. The fragment velocity was measured by time-of-flight (TOF) method, for which the start signal was triggered by a very thin plastic scintillation film detector (TFD) and the stop signal was obtained by a silicon surface barrier detector (SSBD) which was also used for the measurement of the fragment kinetic energy.<BR>The present result of ν(m<SUP>*</SUP>) is in good agreement with that of Apalin et al. and that in the light fragment region of Fraser et al. The obtained TKE(m<SUP>*</SUP>) agrees well with the data of Wagemans et al. A calculation was carried out with the model proposed by Brosa et al. who assumed multichannel fission paths and a random neck rupture. It is seen that the calculated results of both fragment mass dependent kinetic energy and neutron multiplicity represent experimental data well.
- Journal of nuclear science and technology
Journal of nuclear science and technology 32(5), 404-414, 1995-05-25
Atomic Energy Society of Japan