Collinear cluster tripartition as sequential binary fission in the 235^{235}U(nth_{\rm th},f) reaction

The mechanism leading to the formation of the observed products of the collinear cluster tripartition is carried out within the framework of the model based on the dinuclear system concept. The yield of fission products is calculated using the statistical model based on the driving potentials for the fissionable system. The minima of potential energy of the decaying system correspond to the charge numbers of the products which are produced with large probabilities in the sequential fission (partial case of the collinear cluster tripartition) of the compound nucleus. The realization of this mechanism supposes the asymmetric fission channel as the first stage of sequential mechanism. It is shown that only the use of the driving potential calculated by the binding energies with the shell correction allows us to explain the yield of the true ternary fission products. The theoretical model is applied to research collinear cluster tripartition in the reaction $^{235}$U(n$_{\rm th}$,f). Calculations showed that in the first stage of this fission reaction, the isotopes $^{82}$Ge and $^{154}$Nd are formed with relatively large probabilities and in the second stage of sequential fission of the isotope Nd mainly Ni and Ge are formed. This is in agreement with the yield of the isotope $^{68}$Ni which is observed as the product of the collinear cluster tripartition in the experiment.Comment: 20 pages, 9 figure

Manifestations of pear-shaped clusters in collinear cluster tri-partition of 252Cf

Specific mode of the collinear cluster tri-partition of the 252Cf nucleus is discussed. The structure manifests itself as a rhombic-spiral structure in the fission fragments correlation mass distribution

Collinear cluster tripartition as a neutron source - Evaluation of the setup parameters

Forthcoming experiments aimed at studying the mechanism of collinear cluster tripartition are planning to be performed with the new facility. Charged products will be registered with the double arm time -of-flight spectrometer composed of mosaics of PIN -diodes and MCP (micro channel plates) based timing detectors. Several te ns of 3He-filled counters will be gathered round the 252Cf source. In order to choose an optimal configuration of the neutron detector and other parameters of the experiment special modeling has performed using both "neutron barrel" and known MCNP code. Th e first test run of the new facility is in progress also its "neutron skin" in under construction. © 2010 American Institute of Physics.Conference Pape