Ultrasonic Velocity and Attenuation in Liquid Neon

Abstract

A new simple method of ultrasonic velocity and attenuation measurement in a high absorption liquid J. Acoust. Soc. Am. 81, 947 (1987); 10.1121/1.394574 Ultrasonic velocity and attenuation in mammalian tissuesThe velocity and attenuation of 30-MHz sound waves were measured in liquid neon from 25 to 37°K at pressures to 28 kg/em'. The values of the velocity, extrapolated to the vapor pressure curve, are from 1.5% higher at 25°K to 0.4% higher at 32°K than corresponding values reported for 2-GHz sound waves. This negative dispersion is in agreement with recent predictions by Fleury and Boon. Values of the attenuation exceed the classical values calculated from the Navier-Stokes equation. This excess attenuation is attributed to a volume viscosity of the same magnitude as the shear viscosity. No anomaly in the temperature dependence of either velocity or attenuation was observed near the temperature where an anomaly has been reported for thermal conductivity, shear viscosity, and hypersonic velocity.

Thermodynamic Properties and the Velocity of Sound

“…Equation 2.10 shows clearly that some dispersion will be present in every experimentally determined sound velocity. On the other hand the hypersonic velocities obtained at 3 GHz by Fleury and Boon 42 are for liquid argon slightly and for liquid neon definitely lower than the corresponding ultrasonic data 125,77 . This has been illustrated in Figure 1 showing the dispersion data obtained by Greenspan 48 .…”

First Sound and Quantum Effects in Liquid Neon

“…Comparison of recent first sound measurements in liquid Neon indicates that the hypersonic velocity [7], c,, is always smaller than the ultrasonic velocity [8], us. Namely one observes experimentally an average negative dispersion of is of the order of the collision time) places the domain of light scattering in a region intermediate between classical hydrodynamics and generalized hydrodynamics (characterized by o/oc 1 and k/kc -1, where k,' is of the order of the intermolecular distance).…”

Semiclassical many-particle dynamics with gaussian wave packets

“…(12) (13) 3(d2"~ ~* (9) 6o* --Z \-dF/0;~* 2M, M = 1, 2, ... are the time-dependent parameters. In the special case of (3) and (4) the one-particle equations are minimized separately:…”

“…we explain in detail how the experimental energies and pressures were calculated. For a given molar volume V m the vapour-liquid coexistence temperature T v was interpolated from the data of Larson et al[9]. The enthalpy of vaporizationAHv(Vm, Tv) was obtained from the Clausius-Clapeyron equation in the form AHv/(p vAV) = d ln pv/(d ln r~); AV= Vg -Vz; (Vz = V,.).…”