Shielding materials in the compact spherical tokamak
File(s)
Accepted version
Author(s)
Humphry-Baker, Samuel
Smith, George DW
Type
Journal Article
Abstract
Neutron shielding materials are a critical area of development for nuclear fusion technology. In the compact spherical tokamak, shielding efficiency improvements are particularly needed because of severe space constraints. The most spatially restricted component is the central column shield. It must protect the superconducting magnets from excessive radiation-induced degradation, but also from associated heating, so that energy consumption of the cryogenic systems is kept to an acceptable level. Recent simulations show that tungsten carbide and its composites form an attractive class of neutron-attenuating materials. In this paper, the key structure–property relationships of these materials are assessed, as they relate to generic materials challenges for plasma-facing materials. We first consider some fundamental materials properties of monolithic tungsten carbide including thermal transport, mechanical properties and plasma interaction. WC is found to have generally favourable properties compared to metallic tungsten shields. We then report progress on the development of a new candidate cermet material, WC-FeCr. Recent results on its accident safety, thermo-mechanical properties, and irradiation behaviour are presented. This review also highlights the need for further study, particularly in the areas of irradiation damage and hydrogen trapping.
Date Issued
2019-02-04
Date Acceptance
2018-11-12
Citation
Philosophical Transactions A: Mathematical, Physical and Engineering Sciences, 2019, 377 (2141)
ISSN
1364-503X
Publisher
Royal Society, The
Journal / Book Title
Philosophical Transactions A: Mathematical, Physical and Engineering Sciences
Volume
377
Issue
2141
Copyright Statement
© 2019 The Author(s) Published by the Royal Society. All rights reserved.
Subjects
MD Multidisciplinary
General Science & Technology
Publication Status
Published
Article Number
20170443