Towards an optical measurement of the Boltzmann constant at the 10-5 level
LPL, Laboratoire de Physique des Lasers, UMR 7538 C.N.R.S., Université Paris 13, 99 avenue J.-B. Clément, 93430 Villetaneuse, France
2 Institut National de Métrologie, CNAM-INM, 292 rue St Martin, 75141 Paris Cedex 03, France
Corresponding author: firstname.lastname@example.org
We present a new method for direct determination of the Boltzmann constant by laser spectroscopy. The principle consists in recording the linear absorption in a vapour of an atomic or molecular line at a controlled temperature around 273.15 K. By eliminating the pressure broadening, we deduced the pure Doppler width which gives a first optical measurement of the Boltzmann constant kB. The present determination should be significantly improved in the near future and contribute to a new definition of kelvin.
© EDP Sciences, 2008