Magnetization and magnetic relaxation in superfluid /sup 3/He

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1977

OSTI ID:5126711

Sager, R E

Longitudinal magnetic relaxation in superfluid /sup 3/He was studied using an RF-biased SQUID detector to provide continuous monitoring of the longitudinal relaxation following an RF tipping pulse. Experiments in both /sup 3/He-A and /sup 3/He-B were performed in a variety of magnetic fields and in three different geometries. The unusual magnetic relaxation described by Leggett and Takagi is observed for particular geometries in both /sup 3/He-A and /sup 3/He-B within a very limited range of H/sub 0/ and (1-T/T/sub c/). Other observations demonstrate that under certain conditions the longitudinal magnetization in /sup 3/He-A does not relax monotonically in time. Relaxation in /sup 3/He-B very near the critical temperature is shown to be remarkably different following 90/sup 0/ and 180/sup 0/ pulses and experiments using RF pulses with a time dependent frequency provide evidence for a negative frequency shift in /sup 3/He-B at large tipping angles in certain geometries. Using the same combination of SQUID detector and pulsed RF system, new measurements of the static magnetization of /sup 3/He-B were performed in various low magnetic fields and with the /sup 3/He-B in contact with a variety of wall configurations. The results are discussed in the context of previous measurements in both /sup 3/He-A and /sup 3/He-B. At high pressure the data tend toward agreement with resonant-magnetism experiments, while near the polycritical point there still exists a large discrepancy between the results of static and resonance experiments.

• Research Organization: California Univ., San Diego (USA)
• OSTI ID: 5126711
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRITICAL TEMPERATURE
DATA
ELECTRONIC EQUIPMENT
EQUIPMENT
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FLUXMETERS
GEOMETRY
HELIUM 3
HELIUM 3 A
HELIUM 3 B
HELIUM ISOTOPES
INFORMATION
ISOTOPES
LIGHT NUCLEI
MAGNETIC FIELDS
MAGNETIZATION
MATHEMATICS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
NUCLEI
NUMERICAL DATA
PHYSICAL PROPERTIES
PULSES
RELAXATION
RF SYSTEMS
SQUID DEVICES
STABLE ISOTOPES
SUPERCONDUCTING DEVICES
THERMODYNAMIC PROPERTIES
TIME DEPENDENCE
TRANSITION TEMPERATURE