Spin relaxation phenomena in the He-A sub 1 phase. Effects of magnetic field profile, spin counterflow, and sup 4 He coverage

Journal Article · Tue Sep 01 04:00:00 EDT 1992 · Journal of Low Temperature Physics; (United States)

DOI:https://doi.org/10.1007/BF00126599· OSTI ID:6985818

Jiang, Q; Kojima, H ^[1]

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1. Rutgers, The State Univ. of New Jersey, Piscataway (United States)

The authors report observations on the effects of the magnetic field profile and surface coverage by {sup 4}He on the magnetically driven superflows in the {sup 3}He-A{sub 1} phase. When the gradient magnetic field profile is changed: (1) an unexpected reversal in the direction of superflow is observed, and (2) the relaxation time of the induced pressure increases in the warmer region of the A{sub 1} phase but remains constant in the colder region. When the surfaces in the apparatus are covered with {sup 4}He: (1) the induced pressure amplitude decreases and the relaxation time increases and saturates at about twice that of pure {sup 3}He in the warmer side of the phase, and (2) the relaxation time is independent of the {sup 4}He coverage in the colder side. Qualitative interpretation is given of the observed effects in terms of spin density relaxations: in the warmer side of the phase, the spin density relaxes via processes in both bulk liquid and surface boundary; and in the colder side, the spin relaxation is dominated by convective spin counterflows in the A{sub 2}/A phase liquid in the fringing field of the static magnetic field.

• OSTI ID: 6985818
• Journal Information: Journal of Low Temperature Physics; (United States), Journal Name: Journal of Low Temperature Physics; (United States) Vol. 88:5-6; ISSN 0022-2291; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

665420* -- Superfluidity-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANGULAR MOMENTUM
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
HELIUM 3
HELIUM 3 A1
HELIUM 4
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC FIELDS
NUCLEI
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
RELAXATION
SPIN
STABLE ISOTOPES
SUPERFLUIDITY
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE