Projected network performance for multiple isotopes using next-generation xenon monitoring systems.

Since about 2000 (Bowyer et al., 1998), radioxenon monitoring systems have been under development and testing for the verification of the Comprehensive Nuclear Test-Ban Treaty (CTBT). Operation of the systems since then has resulted in development of a next-generation of systems that are nearly ready for operational deployment.

Determining the source of unusual xenon isotopes in samples.

Three unusual radioactive isotopes of xenon-Xe, Xe, and Xe-have been observed during testing of a new generation radioxenon measurement system at the manufacturing facility in Knoxville, Tennessee. These are possibly the first detections of these isotopes in environmental samples collected by automated radioxenon systems. Unfortunately, the new isotopes detected by the Xenon International sampler can interfere with quantification of the radioactive xenon isotopes used to monitor for nuclear explosions.

Investigating the detection of underground nuclear explosions by radon displacement.

A novel approach is proposed to detect underground nuclear explosions (UNEs) through the displacement of natural radon isotopes (Rn and Rn). Following an explosion, it is hypothesized that the disturbance and pressurization of the sub-surface would facilitate the movement of radon from the depth of the UNE towards the surface resulting in increased soil gas activity. The resulting signal may be magnified by a factor of 2.

Equilibrium and nonequilibrium molecular dynamics simulations of the thermal conductivity of molten alkali halides.

The thermal conductivity of molten NaCl and KCl was calculated through the Evans-Gillan nonequilibrium molecular dynamics (NEMD) algorithm and Green-Kubo equilibrium molecular dynamics (EMD) simulations. The EMD simulations were performed for a "binary" ionic mixture and the NEMD simulations assumed a pure system for reasons discussed in this work. The cross thermoelectric coefficient obtained from Green-Kubo EMD simulations is discussed in terms of the homogeneous thermoelectric power or Seebeck coefficient of these materials.

Shear viscosity of molten alkali halides from equilibrium and nonequilibrium molecular-dynamics simulations.

The shear viscosity of molten NaCl and KCl was calculated through equilibrium (EMD) and nonequilibrium molecular-dynamics (NEMD) simulations in the canonical (N,V,T) ensemble. Two rigid-ion potentials were investigated, namely, the Born-Mayer-Huggins-Tosi-Fumi potential and the Michielsen-Woerlee-Graaf-Ketelaar potential with the parameters proposed by Ladd. The NEMD simulations were performed using the SLLOD equations of motion [D.

Operator splitting algorithm for isokinetic SLLOD molecular dynamics.

We apply an operator splitting method to develop a simulation algorithm that has complete analytical solutions for the Gaussian thermostated SLLOD equations of motion [D. J. Evans and G.

An Enskog Correction for Size and Mass Difference Effects in Mixture Viscosity Prediction.

A method is presented which corrects the one-fluid conformal solution viscosity model for size and mass difference effects. This correction, which is based on the Enskog model for hard sphere mixtures, is empirical as applied to transport but has a rigorous basis in equilibrium theory. Comparisons of predictions and experimental viscosities for 24 binary mixtures are presented.