Skip to Main content Skip to Navigation
Journal articles

Emission of Scission Neutrons in the Sudden Approximation

Abstract : At a certain finite neck radius during the descent of a fissioning nucleus from the saddle to the scission point, the attractive nuclear forces can no more withstand the repulsive Coulomb forces producing the neck rupture and the sudden absorption of the neck stubs by the fragments. At that moment, the neutrons, although still characterized by their pre-scission wave functions, find themselves in the newly created potential of their interaction with the separated fragments. Their wave functions become wave packets with components in the continuum. The probability to populate such states gives evidently the emission probability of neutrons at scission. In this way, we have studied scission neutrons for the fissioning nucleus $^{236}$U, using two-dimensional realistic nuclear shapes. Both the emission probability and the distribution of the emission points relative to the fission fragments strongly depend on the quantum numbers of the pre-scission state from which the neutron is emitted. In particular it was found that states with $\Omega \pi$ = 1/2+ dominate the emission. Depending on the assumed pre- and post-scission configurations and on the emission-barrier height, 30 to 50% of the total scission neutrons are emitted from 1/2+ states. Their emission points are concentrated in the region between the newly separated fragments. The upper limit for the total number of neutrons per scission event is predicted to lie between 0.16 and 1.73 (depending on the computational assumptions).
Document type :
Journal articles
Complete list of metadatas

http://hal.in2p3.fr/in2p3-00126282
Contributor : Dominique Girod <>
Submitted on : Wednesday, January 24, 2007 - 3:23:27 PM
Last modification on : Thursday, February 7, 2019 - 5:21:34 PM

Links full text

Identifiers

Collections

Citation

N. Carjan, P. Talou, O. Serot. Emission of Scission Neutrons in the Sudden Approximation. Nuclear Physics A, Elsevier, 2007, 792, pp.102-121. ⟨10.1016/j.nuclphysa.2007.05.006⟩. ⟨in2p3-00126282⟩

Share

Metrics

Record views

110