Considerations for practical conductor design of Chevrel phase wires

It is noticed that the application of PbMo/sub 6/S/sub 8/ (PMS) wires for the generation of steady-state magnetic fields in excess of 20 T requires that several conditions be fulfilled in order to be realistic. Practical design considerations for PbMo/sub 6/S/sub 8/ wires are reported. Besides the availability of wires with sufficient lengths and uniform high critical current density J/sub c/, thermal and mechanical stability have to be achieved. The most severe criterion for thermal stability is based on the prevention of flux jumps in the presence of screening currents in the adiabatic limit. This results in filament diameters between 710 mu m and 90 mu m for critical current densities of 5*10/sup 8/ A/m/sup 2/ and 2*10/sup 9/ A/m/sup 2/, respectively. A dynamic stabilization of a PMS wire in an epoxy-impregnated coil is not very efficient. The behavior of the J/sub c/ of PbMo/sub 6/S/sub 8/ wires under tensile and compressive stress is discussed.