Superfluid turbulence in He II at elevated pressures

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7022862

Mimura, K

The properties of superfluid turbulence in HeII at elevated pressures were studied at 1.385 and 1.600K. The temporal profiles of the temperature gradient in counterflow channels were observed following an application of heat pulses. Two large-aspect-ratio rectangular channels (10.8cm long 2.54 x 0.102cm/sup 2/ and 0.953 x .0826cm/sup 2/ cross-section), each equipped with two heaters at the closed end and three thin-film superconducting bolometers, equally spaced along the channel length, were used in the present work. The channels were made from filled PMMA (Corian). From the steady-state results, the dimensionless coefficient F/sub 0//v/sub 0//sup 3/), which appears in the Schwarz theory of superfluid turbulence, was obtained as a function of temperature and pressure dependent quantity ..cap alpha.. = (B rho/sub n/)/(2 rho). The obtained results are in excellent agreement with the computed results obtained by Schwarz. In effect, this work extends the verification of Schwarz's vortex reconnection model to HeII at pressures of up to 24 bar. The present work also yields new data on the growth and decay of superfluid turbulence in HeII at elevated pressures. The values of Vinen's growth and decay parameters, chi/sub 1/ and chi/sub 2/, are obtained from the analysis of transient behavior of temperature gradients in the channel. The values of chi/sub 2/ derived form transient data show dependence on line density and regime (growth or decay) as well as ..cap alpha...

• Research Organization: Washington Univ., St. Louis, MO (USA)
• OSTI ID: 7022862
• Country of Publication: United States
• Language: English

Related Subjects

420201 -- Engineering-- Cryogenic Equipment & Devices
640450* -- Fluid Physics-- Superfluidity
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOLOMETERS
EVEN-EVEN NUCLEI
FLUIDS
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MEASURING INSTRUMENTS
NUCLEI
PRESSURE EFFECTS
QUANTUM FLUIDS
STABLE ISOTOPES
STEADY-STATE CONDITIONS
SUPERCONDUCTING DEVICES
SUPERFLUIDITY
TURBULENCE