Accession Number:

AD0780167

Title:

Experiments on the Formation and Surface States of Adsorbed Helium Films.

Descriptive Note:

Final technical rept.,

Corporate Author:

SUSSEX UNIV BRIGHTON (ENGLAND)

Personal Author(s):

• Brewer,D. F.

Report Date:

1974-01-01

Pagination or Media Count:

47.0

Abstract:

The aim of this work has been an investigation of phases of He3 and He4 adsorbed on a porous substrate at low temperatures, yielding information on gas surface interactions the formation and structure of films, the effect of size limitation on the properties of three-dimensional material, free surface states on the film, and mean free path effects. The report describes the background to the work, including the recent discovery of superfluidity in liquid He3 which is closely allied to superconductivity in metals. Results of nuclear magnetic resonance measurements on monolayer and submonolayer He3 are described and discussed in terms of the mode of formation of the films. A description is given of the design and construction of a novel type of compressional refrigeration apparatus, and of apparatus to measure the density of adsorbed helium at the lambda transition in He4 and at the critical points of He3 and He4. Author

Descriptors:

• *ADSORPTION
• HELIUM
• FILMS
• POROUS MATERIALS
• PHASE STUDIES
• NUCLEAR MAGNETIC RESONANCE
• SUPERFLUIDITY
• DENSITY
• REFRIGERATION SYSTEMS
• UNITED KINGDOM
• SURFACES
• CRYOGENICS

Subject Categories:

• Physical Chemistry
• Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE