Demonstration of Laser-produced Neutron Diagnostic by Radiative Capture Gamma-rays

TL;DR

This paper introduces a novel laser-produced neutron diagnostic method using delayed gamma-ray signals from radiative captures, enabling effective neutron detection in high-intensity laser experiments.

Contribution

It presents a new time-of-flight technique capturing delayed gamma signals for neutron diagnosis in harsh laser environments, improving detection efficiency.

Findings

Delayed gamma signals correlate linearly with neutron yield.

The method reduces detection issues caused by prompt gamma radiation.

Demonstrates effective neutron diagnostics in high-intensity laser experiments.

Abstract

We report a new scenario of time-of-flight (TOF) technique in which fast neutrons and delayed gamma-ray signals were both recorded in a millisecond time window in harsh environments induced by high-intensity lasers. The delayed gamma signals, arriving far later than the original fast neutron and often being ignored previously, were identified to be the results of radiative captures of thermalized neutrons. The linear correlation between gamma photon number and the fast neutron yield shows that these delayed gamma events can be employed for neutron diagnosis. This method can reduce the detecting efficiency dropping problem caused by prompt high-flux gamma radiation, and provides a new way for neutron diagnosing in high-intensity laser-target interaction experiments.