ANALYSIS OF THE SCISSION NEUTRONS BY A TIME-DEPENDENT APPROACH

In previous papers we studied the properties of the scission neutrons using two approaches: one stationary (the sudden approximation) and one time-dependent. The latter approach involves more complicated calculations but it is more realistic. In the frame of this approach we extend now our calculations to the time evolution of quantities such as: the spatial distribution of the emission points, the current density, the angular distribution with respect to the fission axis and the partition of nu(em)(sc) (the number of emitted neutrons) among the light and the heavy fragments. The scission process is regarded as adiabatic transition from two fragments connected by a thin neck to two separated fragments. To follow this evolution we solve numerically the two-dimensional time-dependent Schrodinger equation with time-dependent potential. Calculations are performed for the nucleus U-236 at different mass divisions. The neutrons released during the scission are followed in time up to T-max = 4x10(-21) s. Their angular distribution is evaluated and compared with experimental data obtained in U-235(n(th),f) reaction.