Room-Temperature Mechanical Strength Selection Criteria of G-10 Intended for Cryogenic Service

Abstract

The Component Development and Integration Facility (CDIF) superconducting magnet features a superconductor support structure that uses G-10 fiberglassepoxy laminate for structural and insulating functions. The magnet for the CDIF magnetohydrodynamic power train is a 45° rectangular saddle, pancake-wound dipole with a graded field (Fig. 1). The conductor is held within longitudinal grooves in fiberglass-epoxy support plates. In this manner, individual conductors are independently supported and separated from adjacent conductors. Cooling within the winding is provided by liquid helium in channels that are machined on the face of the support plates opposite to the conductor grooves. The helium channels are perpendicular to and communicate with the conductor grooves; they provide passages for the liquid helium coolant from the channels to the grooves. Within the groove, a copper wire overwrap on the conductor provides space for helium between the conductor surfaces and the adjacent support plate surfaces. There are 80 support plates, 40 per side, stacked and bolted together to form the winding. A detail of the stacked plates is shown in Fig. 2.

This work was supported by the Fossil Energy/MHD Program of the U. S. Department of Energy through the Francis Bitter National Magnet Laboratory.