The calibration of DD neutron indium activation diagnostic for Shenguang-III facility

TL;DR

This paper details the calibration process of the indium activation diagnostic for DD neutron yield measurements at Shenguang-III, including background correction, simulation, and validation of the calibration accuracy.

Contribution

It introduces a calibration method for the indium activation diagnostic using an accelerator neutron source, including background correction and interference verification.

Findings

Calibration factor of 4.52×10^-7 counts/n with 4.3% uncertainty

Scattered neutron background was about 9% of total neutrons

Linear response range up to 100 cps in the full energy peak

Abstract

The indium activation diagnostic was calibrated on an accelerator neutron source in order to diagnose deuterium-deuterium (DD) neutron yields of implosion experiments on Shenguang-III facility. The scattered neutron background of the accelerator room was measured by placing a polypropylene shield in front of indium sample, in order to correct the calibrated factor of this activation diagnostic. The proper size of this shield was given by Monte Carlo simulation software. The affect from some other activated nuclei on the calibration was verified by judging whether the measured curve obeys exponential decay and contrasting the half life of the activated sample. The calibration results showed that the linear range reached up to 100 cps net count rate in the full energy peak of interest, the scattered neutron background of accelerator room was about 9% of the total neutrons and the possible interferences mixed scarcely in the sample. Subtracting the portion induced by neutron background, the calibrated factor of our sample was 4.52*10^-7 counts/n with uncertainty of 4.3%.