Liquid metal current collectors for homopolar machines

Results of theoretical and experimental studies of liquid metal current collectors, primarily for segmented-magnet (SEGMAG) drum-type homopolar generators, are presented. Current collectors evaluated are of the rotating disk-stationary concentric channel design The liquid metal is the eutectic sodium-potassium alloy (NaK-78). Power losses and disturbing pressures in the liquid metal were either analyzed or evaluated experimentally in terms of rotor speed, temperature, electric current, and magnetic field for prototypic size current collectors. Specific-contact resistance measurements made using these collectors are reported here.