Practical aspects of designing and manufacturing MHD superconducting base-load magnets in 1988 time frame

This paper summarizes a DOE/MIT-FBNML-sponsored study of manufacturing alternatives and producibility of the "cold structure" design for three Base-Load MHD Magnet configurations. The study team consisted of General Dynamics Convair Division (GD), Magnetic Engineering Associates, and Supercon. Two reference designs previously created by AVCO, designated as the BL6-P1 Circular Saddle and the BL6-P2 Rectangular Saddle HD Magnets, were selected for study. The third configuration, identified as a CASK Circular Saddle design, is an innovative concept proposed by the investigators. The three designs have approximately the same magnet field profiles, active lengths, and winding current. Fundamental differences include the winding geometry, and the substructure and superstructure to contain the windings and resist the Lorentz forces. These design differences result in differing use of materials, construction techniques, and assembly procedures. The studies included selection and fabrication of the superconductor/stabilizer, the conductor substructure, turn-to-turn and layer-to-layer insulation, winding approach, and fabrication and assembly of the superstructure. Manufacturing practicality and projected costs were the discriminators for tradeoff considerations. Proposed construction and design alterations permit major manufacturing operations at a central facility. Remaining manufacturing/assembly tasks were simplified to allow final assembly operations on-site. Only known or anticipated (within five years) manufacturing techniques or facilities were recommended. Transportation methods and problems were analyzed and solutions were found for each case. Study results show: 1) that of the two AVCO designs, the circular saddle configuration is a more cost-effective design that lends itself to easier fabrication and on-site assembly, 2) the CASK Base-Load configuration overcomes many of the manufacturing problems inherent in the two AVCO designs.