Manufacture and Test of a Prototype Cyanate Ester Coil

In order to demonstrate that cyanate ester resin could be successfully used in an industrial environment to produce a fusion magnet, a test coil has been made as part of the MAST-Upgrade programme.

I Introduction

Used with glass, cyanate ester is a superior alternative to epoxy for coil insulation systems. It both permits higher operating temperatures and is stronger at all temperatures than the epoxies traditionally used to vacuum impregnate magnets. Cyanate ester also offers superior radiation resistance and easier handling [1], [2]; in particular it has a very long pot life which is important when impregnating large coils such as the ITER toroidal field coils [2], [3]. The main disadvantages are the cost of the resin at present and the lack of experience in industry of working with it for coil manufacture.