Superconducting instrumentation for critical He-4 measurements in space

A proposed superconducting transducer capable of measuring and controlling pressure to within 0.5 nanotorr over a 17 torr range is described. Such a device is capable of ultra-accurate measurements of the isobaric thermal expansion coefficient (Beta sub p), the isothermal compressibility, and the isochoric pressure coefficient of pure He-4 within a few nanoKelvin of the superfluid transition temperature (T sub lambda). Such space-born measurements may be used with specific heat measurements (currently planned for the space shuttle) to test predictions from scaling and renormalization group theory with much higher accuracy than is possible in the Earth-boundary laboratory. New superconducting instrumentation for use in viscosity measurements near T(sub lambda) is discussed. A method of simulating microgravity conditions in He-4 near its superfluid transition using a magnetic field gradient is proposed.