Circular polarization measurement for individual gamma rays in capture reactions with intense pulsed neutrons

TL;DR

This paper develops and demonstrates a polarimeter for measuring circular polarization of gamma rays emitted from neutron capture reactions, providing insights into nuclear structure and parity violation.

Contribution

A novel gamma-ray polarimeter based on magnetic Compton scattering was constructed and tested, enabling precise circular polarization measurements in neutron capture experiments.

Findings

Successful measurement of gamma-ray circular polarization in $^{32}$S($ extbf{n}$,$ extbf{$ extgamma$})$^{33}$S reactions

Performance evaluation of the polarimeter using polarized gamma-ray beams

Potential for studying nuclear spin, parity, and parity nonconservation effects

Abstract

Measurements of circular polarization of $\gamma$-ray emitted from neutron capture reactions provide valuable information for nuclear physics studies. The spin and parity of excited states can be determined by measuring the circular polarization from polarized neutron capture reactions. Furthermore, the $\gamma$-ray circular polarization in a neutron capture resonance is crucial for studying the enhancement effect of parity nonconservation in compound nuclei. The $\gamma$-ray circular polarization can be measured using a polarimeter based on magnetic Compton scattering. A polarimeter was constructed, and its performance indicators were evaluated using a circularly polarized $\gamma$-ray beam. Furthermore, as a demonstration, the $\gamma$-ray circular polarization was measured in $^{32}$S($\vec{\textrm{n}}$,$\gamma$)$^{33}$S reactions with polarized neutrons.