Training behaviour of pressure-impregnated superconducting racetrack magnets

Some small scale tests have been made with racetrack magnets as part of an investigation into the effects of impregnating windings with epoxy resin under pressure. The tests show that training is worse when the epoxy resin is pressurized than when it is used in the normal way and cured at atmospheric pressure. Advantage has been taken of the closed containment shell developed for these tests to try out weak materials such as propylene glycol (a liquid at room temperature) and paraffin wax. When used at atmospheric pressure the behaviour of wax and epoxy resin is identical - neither show training in this type of magnet. (author)