Self-Shielding Copper Substrate Neutron Supermirror Guides

TL;DR

This paper introduces self-shielding copper substrate neutron guides that offer advantages like ease of manufacture, long lifetime, and improved neutron attenuation, with comparable reflectivity and cost to existing solutions.

Contribution

It presents a novel self-shielding copper substrate design for neutron guides, highlighting its manufacturing, safety, and performance benefits over traditional materials.

Findings

Enhanced fast neutron attenuation in the keV-MeV range.

Lower radiation dose to workers due to short-lived isotopes.

No impact on neutron reflectivity performance.

Abstract

The invention of self-shielding copper substrate neutron guides is described, along with the rationale behind the development, and the realisation of commercial supply. The relative advantages with respect to existing technologies are quantified. These include ease of manufacture, long lifetime, increased thermal conductivity, and enhanced fast neutron attenuation in the keV-MeV energy range. Whilst the activation of copper is initially higher than for other material options, for the full energy spectrum, many of the isotopes are short-lived, so that for realistic maintenance access times the radiation dose to workers is expected to be lower than steel and in the lowest zoning category for radiation safety outside the spallation target monolith. There is no impact on neutron reflectivity performance relative to established alternatives, and the manufacturing cost is similar to other polished metal substrates.