Fission of pre-actinide nuclei

TL;DR

This paper investigates the photofission of 181Ta nuclei induced by bremsstrahlung photons at energies of 50 and 3500 MeV, measuring yields and cross sections, and comparing results with CRISP code simulations.

Contribution

It provides new experimental data on photofission yields and cross sections of tantalum at high energies and compares these with theoretical CRISP code simulations.

Findings

Photofission cross sections at 50 and 3500 MeV are 5.4 ± 1.1 μb and 0.77 ± 0.11 mb.

Fissilities are (0.23 ± 0.05) x 10^{-3} and (2.9 ± 0.9) x 10^{-3}.

Mass- and charge-yield distributions were derived from the data.

Abstract

A study of photofission on 181Ta nucleus induced by bremsstrahlung photons with endpoint energies of 50 and 3500 MeV has been performed. The fission yields have been measured by using the induced-activity method in an off-line analysis. The absolute photofission cross sections for the tantalum target at 50 and 3500 MeV are found to be 5.4 \pm 1.1 microb and 0.77\pm0.11 mb, respectively, and the corresponding deduced fissilities are (0.23\pm0.05) x 10^{-3} and (2.9 \pm 0.9) x 10^{-3}. Mass- and charge-yield distributions were derived from the data. The results were compared with the simulated results from CRISP code for multi-modal fission by assuming symmetrical fission mode.