Open AccessThe low-temperature properties of gaseous helium. II
Author(s) -
R. A. Buckingham,
John Hamilton,
H. S. W. Massey
Publication year - 1941
Publication title -
proceedings of the royal society of london. series a, mathematical and physical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.814
H-Index - 135
eISSN - 2053-9169
pISSN - 0080-4630
DOI - 10.1098/rspa.1941.0082
Subject(s) - virial coefficient , helium , van der waals force , thermodynamics , interpretation (philosophy) , viscosity , limit (mathematics) , function (biology) , theorem of corresponding states , atomic physics , value (mathematics) , chemistry , physics , mathematics , van der waals radius , quantum mechanics , statistics , mathematical analysis , molecule , biology , computer science , programming language , evolutionary biology
Some earlier calculations of the second virial and viscosity coefficients of gaseous helium have been extended, using as before the exact quantum formulae. A brief discussion of the atomic interaction, which is expressed in the formV (σ ) = -ϵf (σ ) whereσ =r/r 0 , r0 is the atomic separation whenV is a minimum, andf (1) = 1, is followed by the results of the new calculations and their interpretation. Several interactions, with widely varying values ofϵr 0 2 , have been employed, and inferences about the actual interaction are made by interpolating the available experimental data, a method particularly suitable for interpreting future results. The results of some calculations by de Boer and Michels have been incorporated. It is found that the present data for the second virial coefficient, between 2 and 4.3° K, indicate forϵr 0 2 a value about 122 x 10-16 erg A2 . Though the separate determination ofr 0 andϵ is not likely to be very precise unless calculations are extended to temperatures much beyond the present limit (11° K), the assumption of a probable value for the first van der Waals coefficient leads to the valuesr 0 = 2.93 A,ϵ = 14.2 x 10-16 erg. The influence of possible variations in the functionf (σ ) are discussed and shown to be of secondary importance, and these results are based on a reasonable form forf (σ ) with two parameters. Comparisons are also made with two viscosity measurements below 5° K, but the inferences from these are not at all in agreement with the evidence from the equation of state.