Fission via compound states andJπKA. Bohr's channels: what we can learn from recent studies with slow neutrons

A.L Barabanov,W.I Furman

doi:10.1051/epjconf/20122108002

Abstract

Last data on angular correlations of fission fragments from slow (s-wave) neutron induced binary fission of spin-aligned nuclei 235 U are discussed in the context of Jπ K A. Bohrs channels. Special attention is paid to K = 0 channel. Reasons for its suppression are specified for compound nucleus states of negative parity. A brief overview of recent data on T-odd angular correlations in ternary and binary (with emission of a third particle, a neutron or γ -quantum) fission induced by slow polarized neutrons is presented. On the basis of the developed theoretical approach it is shown that a valuable information on Jπ K fission channels at scission point can be inferred from these T-odd angular correlations.

Highlights

Fission of nuclei by slow neutrons is of great interest due to a possibility of studying of the process’s quantum aspects related to fission channels
We argue that the observed smallness of R effect points out to high accuracy of the above equality
The other mechanism is responsible for formation of T-odd angular correlations in binary fission where the third particle is a γ-quantum or a neutron emitted by one of fragments

Summary

Introduction

Fission of nuclei by slow neutrons is of great interest due to a possibility of studying of the process’s quantum aspects related to fission channels. Bohr’s JπK channels are the angular distributions of fragments from fission of compound states with definite Jπ, i.e. neutron resonances. In the late 1960s and in the early 1970s the coefficient of angular anisotropy has been measured in separated resonances [11,12], and in 1990s in Dubna the angular anisotropy has been studied as function of neutron energy in resonances and between them [13, 14] Analysis of these data provides the most complete information on fission channels with various K. It is the case in the fission of spin-aligned 235U nuclei of negative-parity by slow (s-wave) neutrons

T-odd angular correlations in fission with a third emitted particle x

Conclusion