摘要 |
<p>A plug for a horizontal cryostat penetration comprises a plurality of nested housings with thermal insulation disposed between the housings. Each housing has a tubular extension which is heat stationable to portions of the cryostat penetration, the more inner the housing, the colder being the portion to which it is stationed. The innermost and outermost housings each possess pressure relief means for relieving internal pressure buildup which occurs as a result of magnet quench or vacuum loss. In operation the plug is disposed within the cryostat penetration and in particular, typically within a tubular conduit associated therewith. The tubular extension of the outermost housing also has preferably disposed around its exterior, one or more string-shaped helically disposed lengths of sealing material. Accordingly, when the plug is placed within the penetration, a helical coolant vapor path is formed for plug cooling and exterior ventilation.</p> |