# Total kinetic energy release in the fast neutron induced fission of 232Th and 235U

## TL;DR

This study measures the total kinetic energy release in neutron-induced fission of 232Th and 235U across a range of neutron energies, revealing how TKE varies with energy and fission mode.

## Contribution

It provides detailed measurements of TKE and its variance for 232Th and 235U, highlighting the energy dependence and fission mode effects in neutron-induced fission.

## Key findings

- TKE decreases non-linearly with increasing neutron energy.
- Fission product distributions shift towards symmetric fission at higher energies.
- TKE variances are sensitive indicators of nth chance fission.

## Abstract

We have measured the total kinetic energy release (TKE), its variance and associated fission product distributions for the neutron induced fission of 232Th and 235U for En = 2 - 90 MeV. The neutron energies were determined on an event by event basis by time of flight measurements with the white spectrum neutron beam from LANSCE. The TKE decreases non-linearly with increasing neutron energy for both systems, while the TKE variances are sensitive indicators of nth chance fission. The associated fission product distributions show the decrease in TKE with increasing beam energy that is due to the increasing probability of symmetric fission, which has a lower associated TKE, and the decreasing TKE associated with asymmetric fission, presumably due to the decreasing importance of the A = 132 shell structures.