Studying Near-Critical and Super-Critical Fluids in Reduced Gravity

Critical and supercritical fluids have a variety of applications, from use as machine lubricants in high pressure or high temperature environments to the manufacturing of materials such as aerogel. The optical properties of fluids undergo rapid changes near the critical point resulting in a rapid increase in turbidity known as critical opalescence. These optical changes can be used to probe the universality of critical behavior. As a fluid approaches the critical point, the compressibility rapidly increases. In a gravitational field, this increase in compressibility leads to near-critical fluids stratifying by phase and density, making it difficult to observe the optical properties of the fluid. Therefore it becomes necessary to study critical fluids in a reduced gravity environment. The HYdrogen Levitation DEvice (HYLDE) apparatus at CEA-Grenoble was used to study cells filled with oxygen and hydrogen suspended in a magnetic field as they were gradually decreased from the critical temperature (Tc). Using shadowgraph methods, we analyzed intensity map data to determine the light transmission and turbidity of critical and near critical hydrogen and oxygen. Turbidity measurements were made for a hydrogen filled cell at light wavelengths of 465.2 nm, 519.4 nm, and 669.4 nm. The turbidity of the oxygen filled cell was measured at 400 nm, 450 nm, 500 nm, and 650 nm

Coherent behavior of balls in a vibrated box

We report observations on very low density limit of one and two balls, vibrated in a box, showing a coherent behavior along a direction parallel to the vibration. This ball behavior causes a significant reduction of the phase space dimension of this billiard-like system. We believe this is because the lowest dissipation process along a non-ergodic orbit eliminates ball rotation and freezes transverse velocity fluctuations. From a two-ball experiment performed under low-gravity conditions, we introduce a "laser-like" ball system as a prototype of a new dynamical model for very low density granular matter at nonequilibrium steady state

Master singular behavior from correlation length measurements for seven one-component fluids near their gas-liquid critical point

We present the master (i.e. unique) behavior of the correlation length, as a function of the thermal field along the critical isochore, asymptotically close to the gas-liquid critical point of xenon, krypton, argon, helium 3, sulfur hexafluoride, carbon dioxide and heavy water. It is remarkable that this unicity extends to the correction-to-scaling terms. The critical parameter set which contains all the needed information to reveal the master behavior, is composed of four thermodynamic coordinates of the critical point and one adjustable parameter which accounts for quantum effects in the helium 3 case. We use a scale dilatation method applied to the relevant physical variables of the onecomponent fluid subclass, in analogy with the basic hypothesis of the renormalization theory. This master behavior for the correlation length satisfies hyperscaling. We finally estimate the thermal field extent, where the critical crossover of the singular thermodynamic and correlation functions deviate from the theoretical crossover function obtained from field theory.Comment: Submitted to Physical Review

Characteristic parameters of xenon near its liquid-gas critical point

The mean crossover functions estimated from the bounded results of the Massive Renormalization scheme applied to the 4d (n) model in three dimensions (d = 3) and scalar order parameter (n = 1) are used to represent the singular behaviors of the isothermal compressibility of xenon along the critical isochore in the homogeneous domain and the vapor-liquid coexisting densities of xenon in the nonhomogenous domain. The validity range and the Ising nature of the crossover description are discussed in terms of a single scale factor whose value can be analytically estimated beyond the Ising-like preasymptotic domain

Characteristic parameters of xenon near its liquid-gas critical point

The mean crossover functions estimated from the bounded results of the Massive Renormalization scheme applied to the 4d (n) model in three dimensions (d = 3) and scalar order parameter (n = 1) are used to represent the singular behaviors of the isothermal compressibility of xenon along the critical isochore in the homogeneous domain and the vapor-liquid coexisting densities of xenon in the nonhomogenous domain. The validity range and the Ising nature of the crossover description are discussed in terms of a single scale factor whose value can be analytically estimated beyond the Ising-like preasymptotic domain

Turbidity measurements in xenon reanalyzed using the master crossover functions

The turbidity measurements of Güttinger and Cannell [Phys. Rev. A 24, 3188 (1981)] in the temperature range 20mK < T - Tc < 29:5K along the critical isochore of homogeneous xenon are reanalyzed using the master crossover functions for the isothermal compressibility kt and the correlation length x, without adjustable parameter. We show that the turbidity data are well represented by the Ornstein-Zernike theory, within 1% precision. This excellent agreement conrms that the Ising-like critical behavior of xenon can be described in conformity with the universal features estimated by the massive renormalization scheme, only knowing the four critical coordinates of the vapor-liquid critical point in the (pressure, temperature, molecular volume) phase surface of the monoatomic xenon particle

Characteristic parameters of xenon near its liquid-gas critical point

The mean crossover functions estimated from the bounded results of the Massive Renormalization scheme applied to the 4d (n) model in three dimensions (d = 3) and scalar order parameter (n = 1) are used to represent the singular behaviors of the isothermal compressibility of xenon along the critical isochore in the homogeneous domain and the vapor-liquid coexisting densities of xenon in the nonhomogenous domain. The validity range and the Ising nature of the crossover description are discussed in terms of a single scale factor whose value can be analytically estimated beyond the Ising-like preasymptotic domain

Turbidity measurements in xenon reanalyzed using the master crossover functions

The turbidity measurements of Güttinger and Cannell [Phys. Rev. A 24, 3188 (1981)] in the temperature range 20mK < T - Tc < 29:5K along the critical isochore of homogeneous xenon are reanalyzed using the master crossover functions for the isothermal compressibility kt and the correlation length x, without adjustable parameter. We show that the turbidity data are well represented by the Ornstein-Zernike theory, within 1% precision. This excellent agreement conrms that the Ising-like critical behavior of xenon can be described in conformity with the universal features estimated by the massive renormalization scheme, only knowing the four critical coordinates of the vapor-liquid critical point in the (pressure, temperature, molecular volume) phase surface of the monoatomic xenon particle

Analytic application of the mean crossover function to the description of the isothermal compressibility of xenon

We use the mean crossover functions [Garrabos and Bervillier, Phys Rev. E 74, 021113 (2006)] estimated from the bounded results of the Massive Renormalization scheme applied to the $\Phi_{d}^{4}\left(n\right)$ model in three dimensions ($d=3$) and scalar order parameter ($n=1$) [Bagnuls and Bervillier, Phys. Rev. E 65, 066132 (2002)], to represent the singular behavior of the isothermal compressibility of xenon along the critical isochore in the homogeneous preasymptotic domain. The validity range and the Ising nature of the crossover description are discussed in terms of a single scale factor whose value can be analytically estimated beyond the Ising-like preasymptotic domain

Analytic application of the mean crossover function to the description of the isothermal compressibility of xenon

We use the mean crossover functions [Garrabos and Bervillier, Phys Rev. E 74, 021113 (2006)] estimated from the bounded results of the Massive Renormalization scheme applied to the $\Phi_{d}^{4}\left(n\right)$ model in three dimensions ($d=3$) and scalar order parameter ($n=1$) [Bagnuls and Bervillier, Phys. Rev. E 65, 066132 (2002)], to represent the singular behavior of the isothermal compressibility of xenon along the critical isochore in the homogeneous preasymptotic domain. The validity range and the Ising nature of the crossover description are discussed in terms of a single scale factor whose value can be analytically estimated beyond the Ising-like preasymptotic domain