CRYOGENIC DESIGN OF THE LIQUID-HELIUM EXPERIMENT CRITICAL-DYNAMICS INMICROGRAVITY

Although many well-controlled experiments have been conducted to measu re the static properties of systems near criticality, few experiments have explored the transport properties in systems driven far away from equilibrium as a phase transition occurs. The cryogenic design of an experiment to study the dynamic aspect of critical phenomena is report ed here. Measurements of the thermal gradient across the super-fluid ( He Il)-normal fluid (He I) interface in helium under microgravity cond itions will be performed as a heat flux holds the system away from equ ilibrium. New technologies are under development for this experiment, which is in the definition phase for a space shuttle flight. (C) 1996 Elsevier Science Limited