The existence of different fission behavior of hot nuclei formed in central and peripheral collisions was found from the systematic analysis of the mass and energy distributions of fission fragments as a function of the initial temperature of hot fissioning nuclei.
Moreover, the dependencies of isotope effect on asymmetric fission and fissioning system size are also studied within the framework of a statistical model modified to include the effects of dissipation in fission by systematically investigating prescission particle evaporation of a light In isotope chain and a medium heavy Er isotope chain.
The dynamical calculation of quasi fission reaction induced by 10.6MeV/u 84 Kr on 27 Al is performed using one body dissipation model. The calculation suggests a fission time larger than 200×10 -22 sec. It is found that the threshold for emergence of quasi fission in the reactoin system is 8 MeV/u.
A description is given of the principle, method and technology to determine the tissue kerma rates of the neutron and γ-rays in a fission neutron field produced by a fast reactor with a IRM81-TE1 tissue-equivalent ionization chamber made in China and a low neutron sensitivity energy-compensated G-M counter. Meanwhile, measurements are made with a FWTIC-17A tissue-equivalent ionization chamber. The results determined with the two chambers agree well with each other.
In addition to the main process of binary fission, three branches of collinear three-body disintegration, which are associated with various mechanisms of the excitation of a deformed fissioning nucleus, are observed.
The analysis performed reveals that the coordinate-independent reduction coefficient ks is not compatible with the simultaneous description of the main fission characteristics for fissioning systems heavier than 224Th.
It is emphasized that angular anisotropy and various angular correlations of fission products are possible only if the fissioning nucleus remains nonthermalized during all the stages of fission from the saddle point to scission.
In contrast to prompt neutrons, scission neutrons are expected to mostly depend on the characteristics of the fissioning nucleus and, in particular, on its neutron number N.
The analysis is done for five compound nuclear systems representing heavy fissioning nuclei, medium fissioning nuclei, and a light fissioning one with the angular momentum varied in a wide range from l = 0 to 70?.