Speaker
Description
It is generally accepted that prompt fission neutrons (PFN) have
two components with unknown relative intensities: neutrons dynami-
cally released at scission (SN) and neutrons evaporated from fully ac-
celerated fragments (EVN). There is no indication which of these two
components is the dominant one since the gross features of PFN can be
reproduced by both models [1, 2, 3]. To remove the ambiguity, instead
of looking at averaged properties, one has to study PFN observables
correlated with fragment properties.
It has been pointed out [2] that, for a fixed fragment-mass divi-
sion, the kinetic energy spectrum and the angular distributions with
respect to the fission axis of EVN and of SN are different: the first are
smooth while the second present oscillations. In the case of angular
distribution, the oscillations are due to the proximity of the fragments
at the moment of emission. The calculated spectrum is not smooth
since it consists of a finite weighted sum (only 35 non-negligible terms)
of individual contributions with different mean values and widths.
To confirm or infirm experimentally the existence of fine structures
in the angular and energy distributions of PFN is of outmost impor-
tance. It unveils the origin of the neutron emission during fission which
is the best known and most discussed feature of nuclear fission.
[1] N.Carjan, M. Rizea, Phys. Lett. B 747, 178 (2015).
