"Set and Hold With Power Off" Cryogenic Actuators

Magnetostrictive actuators that would hold their displacements with power turned off have been proposed for use at temperatures from about 10 to about 77 K. Such "set and hold with power off" actuators are attractive for effecting fine position adjustments in cryogenic scientific instruments, wherein significant amounts of heat would be released and could disturb instrument operation if it were necessary to apply power continually to maintain actuator displacements.