# Measurement of the neutron beam profile of the Back-n white neutron facility at CSNS with a Micromegas detector

## TL;DR

This paper presents the development and testing of a Micromegas detector to measure the neutron beam profile at the Back-n facility of CSNS, providing initial beam distribution data for nuclear research.

## Contribution

It introduces a specialized Micromegas detector for neutron beam profiling and reports its successful application at the Back-n neutron source.

## Key findings

- Successful measurement of the neutron beam profile
- Demonstrated detector's gain and uniformity performance
- First measurement of the Back-n neutron beam spot

## Abstract

The Back-n white neutron beam line, which uses back-streaming white neutrons from the spallation target of the China Spallation Neutron Source, is used for nuclear data measurements. A Micromegas-based neutron detector with two variants was specially developed to measure the beam spot distribution for this beam line. In this article, the design, fabrication, and characterization of the detector are described. The results of the detector performance tests are presented, which include the relative electron transparency, the gain and the gain uniformity, and the neutron beam profile reconstruction capability. The result of the first measurement of the Back-n neutron beam spot distribution is also presented.