Fission mode fluctuations in the resonances of 235U (n,f)
Fission fragment mass- and total kinetic energy distributions were measured for single, isolated resonances and neutron energy bins covering the incident neutron energy range from 0.006 eV to 130 eV. The measurements were performed at the Geel Electron Linear Accelerator (GELINA) of the European Communities using a Frisch-gridded ionization chamber. Fluctuations of the fission fragment mass distributions as a function of resonance energy were observed, which were correlated with fluctuations of the reactions Q-value and with the measured total kinetic energy (TKE) averaged over all fragments. In the resonance region the fluctuations in TKE from resonance to resonance are observed with amplitudes up to about 450 keV. The correlations between the mass-distribution fluctuations and parameters like spin, spin orientation quantum number, angular distribution fluctuations and the fluctuations of the average number of neutrons emitted in fission, are evaluated. An interpretation of the v-fluctuations observed in other experiments is given in terms of the mass distribution fluctuations. The fluctuations of the mass-distribution parameters and of the total kinetic energy distributions as a function of mass are viewed in the frame of the fission channel model of Bohr and Wheeler and of the recent multi-fission mode random neck-rupture model of Brosa, Grossmann and Müller.
Bibliographic Reference: Article: Nuclear Physics, Vol. A491 (1989), pp. 56-90
Record Number: 198910453 / Last updated on: 1994-12-01
Original language: en
Available languages: en