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S. T. West

Publications and source records attributed to S. T. West.

5 recordsLinked to original sources

Elpasolite Planetary Ice and Composition Spectrometer (EPICS): A Low-Resource Combined Gamma-Ray and Neutron Spectrometer for Planetary Science

Neutron and gamma-ray spectroscopy (NGRS) is a well established technique for studying the geochemical composition and volatile abundance relevant to planetary structure and evolution of planetary bodies. Previous NGRS instruments have used separate gamma-ray and neutron spectrometers. The Elpasolite Planetary Ice and Composition Spectrometer (EPICS) instrument is an innovative and fully integrated NGRS with low resource requirements. EPICS utilizes elpasolite scintillator read out by silicon photomultipliers to combine the gamma-ray and neutron spectrometer into a single instrument, leading to a significant reduction in instrument size, weight, and power. An overview and motivation for the EPICS instrument, current status of the EPICS development, and a discussion of the expected sensitivity and performance are presented.

physics.ins-det

Z(3) Interfaces in Lattice Gauge Theory

A study is made of properties of the Z(3) interface which forms between the different ordered phases of pure SU(3) gauge theory above a critical temperature. The theory is simulated on a (2+1)-D lattice at various temperatures above this critical point. At high temperatures, the interface tension is shown to agree well with the prediction of perturbation theory. Near the critical temperature, the interface behaviour is characterised by various displacement moments, and modelled by an interacting scalar field theory. This thesis is provided for reference, as it gives full details of the computational and statistical methods outlined only briefly in preprints hep-lat/9605040 and hep-lat/9607005.

hep-lat

Critical properties of the Z(3) interface in (2+1)-D SU(3) gauge theory

We study the interface between two different Z(3) vacua in the deconfined phase of SU(3) pure gauge theory in 2+1 dimensions just above the critical temperature. In simulations of the Euclidean lattice gauge theory formulation of the system we measure the fluctuations of the interface as the critical temperature is approached and as a function of system size. We show that the intrinsic width of the interface remains small even very close to the critical temperature. Some dynamical exponents which govern the interaction of the interface with our Monte Carlo algorithm are also estimated. We conclude that the Z(3) interface has properties broadly similar to those in many other comparable statistical mechanical systems.

hep-lat

High-Temperature Properties of the Z(3) Interface in (2+1)-D SU(3) Gauge Theory

We study the high-temperature properties of the Z(3) interface which forms between the various ordered phases of pure SU(3) gauge theory above a critical temperature. On a (2+1)-D Euclidean lattice, we perform an accurate measurement of the interface tension, which shows good agreement with the prediction of perturbation theory. We also examine the behaviour of the Debye electric screening mass, and compare this with theoretical predictions.

hep-lat

Properties of the Z(3) Interface in (2+1)-D SU(3) Gauge Theory

A study is made of some properties of this interface in the SU(3) pure gauge theory in 2+1 dimensions. At high temperatures, the interface tension is measured and shows agreement with the perturbative prediction. Near the critical temperature, the behaviour of the interface is examined, and its fluctuations compared to a scalar field theory model.

hep-lat