Momentum distribution of normal and superfluid helium

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7163354

Sosnick, T R

Deep inelastic neutron scattering measurements have been preformed on normal and superfluid helium to measure the single-particle momentum distribution and the Bose condensate fraction. These measurements were conducted at a momentum transfer of 23{angstrom}{sup {minus}1} using the new PHOENIX chopper spectrometer at the Intense Pulsed Neutron Source at Argonne National Laboratory. A analysis procedure involving Y-scaling is implemented on a temperature dependent study of the normal and superfluid at T = 0.35 to 4.2 K at a constant density of 0.147 gm/cm{sup 3}. The density dependence of the single-particle kinetic energy is studied in the normal fluid at six different densities ranging from 0.125 to 0.171 gm/cm{sup 3}. The data in the superfluid are compared to the Impulse Approximation prediction of ground state theoretical momentum distributions and significant deviations at the peak center are observed. In the constant density measurement, the observed kinetic energies in the superfluid, {approx}14 K, and in the normal fluid, {approx}16 K, are almost constant but show an increase across the superfluid transition. The calculated values for the kinetic energy are in very good agreement with the theoretical predictions in both the normal and the superfluid.

• Research Organization: Harvard Univ., Boston, MA (USA)
• OSTI ID: 7163354
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BOSE-EINSTEIN CONDENSATION
CALCULATION METHODS
DATA
DATA ANALYSIS
DEEP INELASTIC SCATTERING
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HELIUM
INELASTIC SCATTERING
INFORMATION
INTERACTIONS
LEPTON-BARYON INTERACTIONS
LEPTON-HADRON INTERACTIONS
LEPTON-NUCLEON INTERACTIONS
MEASURING INSTRUMENTS
MEASURING METHODS
MOMENTUM TRANSFER
NEUTRON SPECTROSCOPY
NONMETALS
NUMERICAL DATA
PARTICLE INTERACTIONS
RARE GASES
SCATTERING
SPECTROSCOPY
SUPERFLUIDITY