Issue
EPL
Volume 83, Number 1, July 2008
Article Number 15001
Number of page(s) 5
Section Physics of Gases, Plasmas and Electric Discharges
DOI http://dx.doi.org/10.1209/0295-5075/83/15001
Published online 11 June 2008
EPL, 83 (2008) 15001
DOI: 10.1209/0295-5075/83/15001

Molar polarizability change in gaseous 4He far from the condensation possibly due to the creation of bosonic clusters

C. Gaiser and B. Fellmuth

Physikalisch-Technische Bundesanstalt - Abbestr. 2-12, 10587 Berlin, Germany, EU

christof.gaiser@ptb.de

received 28 February 2008; accepted in final form 15 May 2008; published July 2008
published online 11 June 2008

Abstract
With dielectric-constant gas thermometry (DCGT) a sudden change in the low-temperature properties of gaseous 4 He has been observed. Below 3.3 K, the usual real-gas behavior ends. The change can be explained by the assumption of clustering 4He atoms. Such clusters influence the molar polarizability and the dielectric virial coefficients. This causes wrong thermodynamic temperature results of DCGT with 4He. Consistency checks with 3He revealed the best experimental value for the polarizability of 3He up to now and confirmed the feasibility of DCGT in the treated temperature range.

PACS
51.30.+i - Thermodynamic properties, equations of state.
51.70.+f - Optical and dielectric properties.
36.40.Cg - Electronic and magnetic properties of clusters.

© EPLA 2008