Tracking fast neutrons

TL;DR

This paper proposes methods for tracking fast neutrons using ion recoil tracks and vertex positions, discussing detector technologies like multi-wire chambers and light-field imaging, with resolutions limited by ion range straggling.

Contribution

It introduces a novel approach to measure neutron momentum with minimal ion track data and explores the potential of light-field imaging for neutron detection.

Findings

Neutron momentum can be measured with as few as 1.5 ion tracks.

Resolution limited to about 10% by ion range straggling.

Light-field imaging offers a charge-blur-free detection method.

Abstract

Based on elastic collisions, the linear momentum of a fast neutron can be measured from as few as two consecutive recoil ion tracks plus the vertex position of the third collision, or `two and half' ion tracks. If the time delay between the first two consecutive ion tracks is also measured, the number of ion tracks can be reduced to one and a half. The angular and magnitude resolutions are limited by ion range straggling to about ten percent. Multi-wire proportional chambers and light-field imaging are discussed for fast neutron tracking. Single-charge or single-photon detection sensitivity is required in either approach. Light-field imaging is free of charge-diffusion-induced image blur, but the limited number of photons available can be a challenge. $^1$H,$^2$H and $^3$He could be used for the initial development of fast neutron trackers based on light-field imaging.