title: Weightless experiments to probe universality of fluid critical behavior.
abstract: Near the critical point of fluids, critical opalescence results in light attenuation, or turbidity increase, that can be used to probe the universality of critical behavior. Turbidity measurements in SF6 under weightlessness conditions on board the International Space Station are performed to appraise such behavior in terms of both temperature and density distances from the critical point. Data are obtained in a temperature range, far (1 K) from and extremely close (a few μK) to the phase transition, unattainable from previous experiments on Earth. Data are analyzed with renormalization-group matching classical-to-critical crossover models of the universal equation of state. It results that the data in the unexplored region, which is a minute deviant from the critical density value, still show adverse effects for testing the true asymptotic nature of the critical point phenomena.
authors.affiliation: CNRS, ICMCB, ESEME, UPR 9048, F-33600 Pessac, France.|Université Bordeaux, ICMCB, UPR 9048, F-33600 Pessac, France.
authors.forename: C
authors.initials: C
authors.lastname: Lecoutre
authors.affiliation: CNRS, ICMCB, ESEME, UPR 9048, F-33600 Pessac, France.|Université Bordeaux, ICMCB, UPR 9048, F-33600 Pessac, France.
authors.forename: R
authors.initials: R
authors.lastname: Guillaument
authors.affiliation: CNRS, ICMCB, ESEME, UPR 9048, F-33600 Pessac, France.|Université Bordeaux, ICMCB, UPR 9048, F-33600 Pessac, France.
authors.forename: S
authors.initials: S
authors.lastname: Marre
authors.affiliation: CNRS, ICMCB, ESEME, UPR 9048, F-33600 Pessac, France.|Université Bordeaux, ICMCB, UPR 9048, F-33600 Pessac, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Garrabos
authors.affiliation: Physique et Mécanique des Milieux Hétérogènes, UMR 7636 CNRS - ESPCI - Université Pierre et Marie Curie - Université Paris Diderot, 10 rue Vauquelin, 75005 Paris, France.|Service des Basses Températures, CEA-Grenoble & Université Joseph Fourier, F-38000 Grenoble, France.
authors.forename: D
authors.initials: D
authors.lastname: Beysens
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, California 91109, USA.
authors.forename: I
authors.initials: I
authors.lastname: Hahn