Size effects in superfluid /sup 3/He

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6049057

Chainer, T J

The superfluid density and transition temperature of /sup 3/He filling the pores of packed alumina powder have been measured by fourth sound. The measurements were performed simultaneously for three separate fourth sound resonators, each packed with a different nominal grain size of 1.0 ..mu..m. 0.3 ..mu..m and 0.05 ..mu..m. The bulk /sup 3/He superfluid transition temperature, which was determined independently, was compared to the transition temperature of each resonator. We observed a systematic depression for both the superfluid density and transition temperature as the powder size was decreased. The depressions in the transition temperature were compared with theoretical estimates of size dependent transition temperatures for the ideal geometry of an infinite cylinder. In the analysis the cylinder radius was replaced by defining an average radius of the pore structure which was empirically determined by nitrogen gas sorption and mercury intrusion techniques. The pressure dependence of the transition temperature depression is found to be consistent with theoretical estimates of the superfluid coherence length. The experimentally determined magnitude of the coherence length based on the pore structure analysis is in agreement with theoretical estimates, confirming that the coherence length of superfluid /sup 3/He is about two orders of magnitude larger than that of He II.

• Research Organization: Rutgers--the State Univ., New Brunswick, NJ (USA)
• OSTI ID: 6049057
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
COHERENCE LENGTH
DATA
DENSITY
DIMENSIONS
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FOURTH SOUND
HELIUM 3
HELIUM ISOTOPES
INFORMATION
ISOTOPES
LENGTH
LIGHT NUCLEI
NUCLEI
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POROSITY
PRESSURE DEPENDENCE
STABLE ISOTOPES
SUPERFLUIDITY
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE