A SPECIFIC HEAT AND FOURTH SOUND MEASUREMENT OF SIZE EFFECTS IN LIQUID HELIUM.

Abstract

An experimental and theoretical investigation of liquid helium confined to the small pores of highly compressed powders was made in order to investigate size effects in liquid helium. The specific heat measurements show that the bulk specific heat singularity is replaced by a flattened peak that is shifted towards lower temperatures with decreasing pore size. The theory of second order phase transitions was used to calculate the specific heat of liquid helium in finite systems. The superflow onset temperature and the super fluid fraction were determined from fourth sound (hydrodynamic pressure waves) measurements in the same powders in which specific heat measurements were made. The onset temperature and the temperature of the specific heat peak are equal within experimental error. (Author)

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1969
Accession Number
AD0699162

Entities

People

  • Stephen Allan Scott

Organizations

  • University of California, Los Angeles

Tags

DTIC Thesaurus Topics

  • Critical Temperature
  • Energy
  • Glass Transition Temperature
  • Heat Energy
  • Measurement
  • Phase Transformations
  • Specific Heat
  • Transition Temperature
  • Transitions

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Combustion and Flow Dynamics.
  • Powder metallurgy of Titanium alloys.