主权项 |
1. A header assembly, comprising:
a concave cap plug having upper and lower surfaces; a cap having upper and lower surfaces,
the cap plug and the cap being sealably assembled to as to define an insulating volume within,the insulating volume being defined by an lower surface of the cap and an upper surface of the cap plug,the insulating volume being at a vacuum; at least one cap tube having a lumen, the lumen of the at least one cap tube extending through an aperture of the cap, through the insulating volume, and through an aperture of the cap plug. |