Neutron imaging detector based on the muPIC micro-pixel chamber

TL;DR

This paper presents a prototype neutron imaging detector using muPIC micro-pixel chambers, achieving high spatial and time resolution, effective gamma-ray rejection, and suitability for high-intensity neutron source applications.

Contribution

The development of a time-resolved neutron imaging detector with detailed tracking and background rejection capabilities using muPIC technology.

Findings

Spatial resolution of 349 microns achieved

Gamma sensitivity of 10^-12 or less demonstrated

Time resolution of 0.6 microseconds achieved

Abstract

We have developed a prototype time-resolved neutron imaging detector employing the micro-pixel chamber (muPIC), a micro-pattern gaseous detector, coupled with a field programmable gate array-based data acquisition system for applications in neutron radiography at high-intensity neutron sources. The prototype system, with an active area of 10cm x 10cm and operated at a gas pressure of 2 atm, measures both the energy deposition (via time-over-threshold) and 3-dimensional track of each neutron-induced event, allowing the reconstruction of the neutron interaction point with improved accuracy. Using a simple position reconstruction algorithm, a spatial resolution of 349 +/- 36 microns was achieved, with further improvement expected. The detailed tracking allows strong rejection of background gamma-rays, resulting in an effective gamma sensitivity of 10^-12 or less, coupled with stable, robust neutron identification. The detector also features a time resolution of 0.6 microseconds.