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Theses
Photo-association de l'hélium métastable au voisinage de la Condensation de Bose-Einstein et formation de dimères géants
Abstract : In the vicinity of Bose-Einstein condensation, the collisional
properties of a dilute gas of metastable helium (He $2^3S$) are
governed by the rate of ionizing Penning collisions and the s-wave
scattering length. In order to investigate these properties, we have carried out new photoassociation experiments in which a pair of free atoms absorbs a photon to produce a molecule in an excited electronic state. In particular, we have observed ``giant dimers" for which the autoionizing process is inhibited. Accurate spectra have been acquired by the use of an original `calorimetric" detection scheme. In addition, we have calculated long-range electronic potentials for the $2^3S+2^3P$ system. Our asymptotic approach is described in detail, which reproduces the measured binding energies of the giant dimers with
very good accuracy.
properties of a dilute gas of metastable helium (He $2^3S$) are
governed by the rate of ionizing Penning collisions and the s-wave
scattering length. In order to investigate these properties, we have carried out new photoassociation experiments in which a pair of free atoms absorbs a photon to produce a molecule in an excited electronic state. In particular, we have observed ``giant dimers" for which the autoionizing process is inhibited. Accurate spectra have been acquired by the use of an original `calorimetric" detection scheme. In addition, we have calculated long-range electronic potentials for the $2^3S+2^3P$ system. Our asymptotic approach is described in detail, which reproduces the measured binding energies of the giant dimers with
very good accuracy.
Cited literature [117 references]
https://tel.archives-ouvertes.fr/tel-00004295
Contributor : Jérémie Léonard Connect in order to contact the contributor
Submitted on : Friday, January 23, 2004 - 1:39:15 PM
Last modification on : Thursday, March 17, 2022 - 10:08:06 AM
Long-term archiving on: : Friday, April 2, 2010 - 7:26:44 PM
Contributor : Jérémie Léonard Connect in order to contact the contributor
Submitted on : Friday, January 23, 2004 - 1:39:15 PM
Last modification on : Thursday, March 17, 2022 - 10:08:06 AM
Long-term archiving on: : Friday, April 2, 2010 - 7:26:44 PM