Ar-Xe Mixtures Research Articles

Combining rules for intermolecular potential parameters. I. Rules for the Dymond-Alder potential

A new combining rule for the collision diameters of the Dymond-Alder pair potential function has been introduced. The rule was obtained by considering the long-range repulsive interactions of noble gas atoms, and gives the parameter for an interaction between unlike molecules as a weighted algebraic mean of those for the corresponding like-pair interactions. It is shown that the rule works very well in predicting the second virival coefficients of Ne–Ar, Ar–Kr, and Ar–CH4 mixtures and the binary diffusion coefficients of Ne–Ar, Ne–Kr, Ne–Xe, Ar–Kr, and Ar–Xe mixtures when it is used in conjunction with the previously proposed rule for the potential well-depth parameters, εij = 2εiiεjj/(εii + εjj).

Gas Proportional Scintillation Counter with Xenon and Xenon Mixtures

The light output of the recently developed gas proportional scintillation counter - a gas scintillation counter with light multiplication produced by a cylindrical geometry electric field - is investigated for heavy gaseous media under alpha particle excitation with a 56 UVP phototube. The gases used are Xe, and Xe-Ar and Xe-N2 mixtures for a wide range of concentrations, at a total pressure of about 965 Torr. The light output of the Xe-Ar mixtures shifts towards the ultraviolet (λ ≲ 3250 Å) region as the electric field intensity increases. Xe-Ar mixtures with Xe concentrations ranging from about 1 to 10% give - with a p-quaterphenyl wavelength shifter - a light output more than two orders of magnitude larger than that of a CsI(T1) scintillator. In Xe-N2 mixtures - with wavelength shifter - nitrogen has a quenching effect. For the mixtures of noble gases the rise time of the secondary component of the light pulse is slow, typically 15 μs. Methane and nitrogen while having a quenching effect, reduce this rise time.

Sulphide ides in cement

The distortion of absorption profile due to multiple passes resulting from reflections at the windows of an optical cell is considered. A general method applicable to absorption in any spectral region is developed. In particular calculations are performed for collision induced far infrared absorption by rare gas mixtures. Such a calculation, in addition to the optical properties of the window material, needs the knowledge of the refractive index of the sample in the region of interest. It is shown that for rare gas mixtures, the translational contribution to the refractive index is negligible. The electronic contribution is obtained from the additivity of molar refractivities. The “true” absorption profile for Xe-Ar mixture is deduced from the observed profile obtained using a cell with diamond windows. This “true” profile in turn is used to obtain the expected profiles of the mixture with silicon and germanium windows. The suitability of this procedure will be demonstrated in a subsequent communication in which the results on integrated absorption for translational spectra of several rare gas mixtures will be presented.

Experimental-retort tests of orient coal

The distortion of absorption profile due to multiple passes resulting from reflections at the windows of an optical cell is considered. A general method applicable to absorption in any spectral region is developed. In particular calculations are performed for collision induced far infrared absorption by rare gas mixtures. Such a calculation, in addition to the optical properties of the window material, needs the knowledge of the refractive index of the sample in the region of interest. It is shown that for rare gas mixtures, the translational contribution to the refractive index is negligible. The electronic contribution is obtained from the additivity of molar refractivities. The “true” absorption profile for Xe-Ar mixture is deduced from the observed profile obtained using a cell with diamond windows. This “true” profile in turn is used to obtain the expected profiles of the mixture with silicon and germanium windows. The suitability of this procedure will be demonstrated in a subsequent communication in which the results on integrated absorption for translational spectra of several rare gas mixtures will be presented.

Application of the interferometer to gas analysis

The distortion of absorption profile due to multiple passes resulting from reflections at the windows of an optical cell is considered. A general method applicable to absorption in any spectral region is developed. In particular calculations are performed for collision induced far infrared absorption by rare gas mixtures. Such a calculation, in addition to the optical properties of the window material, needs the knowledge of the refractive index of the sample in the region of interest. It is shown that for rare gas mixtures, the translational contribution to the refractive index is negligible. The electronic contribution is obtained from the additivity of molar refractivities. The “true” absorption profile for Xe-Ar mixture is deduced from the observed profile obtained using a cell with diamond windows. This “true” profile in turn is used to obtain the expected profiles of the mixture with silicon and germanium windows. The suitability of this procedure will be demonstrated in a subsequent communication in which the results on integrated absorption for translational spectra of several rare gas mixtures will be presented.