Fissile Nuclei Rotation Effect in U-235(n, gamma f) Process

A small shift of an angular distribution of prompt gamma-rays relative to the fission axis of U-236* in U-235(n, gamma f) process is presented. This effect has been observed in the experiment at BER-II reactor of BENSC/HMI (Berlin). The sign of the shift depends on the direction of the incident neutron beam polarization. This phenomena can be explained by the rotation of fissile nucleus U-236*, like the effect that has been observed recently at ILL in ternary fission of U-235 by cold polarized neutrons. The main surprise of this result is the detection of scission gamma-rays radiated by a fissile nucleus during the time interval of the order of 10(-21) s before or after the moment of the neck rupture. Detailed measurements of trigger gamma-rays energy dependence are in progress at the neutron hewn "MEPHiSTO" of FRM-II reactor (Garching).