THE PERMEABILITY OF RESIN-BASED COMPOSITE-MATERIALS TO RADIOLYTIC GASES

When the insulation of a superconducting magnet is irradiated, the rad iolytic gases will be produced in a condensed form and on ly mobilised when the magnet is warmed, following irradiation. The extent to which these gases will permeate through the resin or remain trapped within the polymer structure is not yet fully understood. Trapped gases may r esult in internal stress, cause swelling within the polymer and contri bute to a degradation of electrical performance. The quantity of gas w hich remains trapped within the polymer structure is thought to be a f unction of the internal pressure, material thickness and the permeabil ity of the various gases that may be formed. The study, detailed in th is report, was undertaken to estimate the time scale and extent to whi ch gases, produced and trapped following low temperature irradiation, will be lost by permeation through the insulation when it is warmed to 293 K. This work follows from an earlier report which showed that dif ferent amounts of gas were evolved when the same resin was irradiated in different geometric forms. (C) 1998 Published by Elsevier Science L td. All rights reserved.