An Indirect Measurement of $^6$Li(n,$\gamma$) Cross Sections

TL;DR

This paper presents an indirect experimental method to measure the $^6$Li(n,$ extgamma$)$^7$Li cross sections in the 0.6 to 4 MeV neutron energy range, combining experimental data with theoretical calculations.

Contribution

It introduces an indirect measurement approach for neutron capture cross sections using gamma transition probabilities and theoretical modeling, advancing the methodology in nuclear reaction studies.

Findings

Measured cross sections align with theoretical calculations.

Coupling of resonant states influences neutron capture spectra.

Experimental gamma transition data supports indirect cross section estimation.

Abstract

The $^6$Li(n,$\gamma$)$^7$Li cross sections in the neutron energy range of 0.6 to 4 MeV have been measured by the experimental implementation of the direct capture formalism. This was done by measuring the $\gamma$ transition probability experimentally and accounting for the spin factor by theoretical calculation. The electromagnetic transition probabilities from $^7$Li$^*$ analogous to the initial neutron capture states of $^6$Li$+n$ were measured by populating the J$_i$ states of $^7$Li through $^7$Li($p,p'$)$^7$Li$^*$ reaction. The impact of coupling of resonant states, above neutron separation threshold of $^7$Li, in the neutron capture, is observed from the capture $\gamma$ spectrum. The measured cross sections were reproduced through {\sc fresco} and Talys-1.95 Direct Capture Calculations.