Abstract: An apparatus for producing a stable, high pressure plasma column with long length, and high axial uniformity. Rotating a gas-filled tube about an horizontal axis creates a vortex with minimal, or no shear flow. Such a vortex provides a stable equilibrium for a central column of high temperature gas and plasma when, for a given rotation speed, the centrifugal force dominates over the gravitational force inside the smallest radial dimension of the containment envelope. For gas pressures sufficiently high that the particle mean free path is short compared with the thickness of the gas layer between the central plasma column and the wall, thermal transport across this sheath layer is small and its temperature is low. High pressure discharges inside a rotating envelope may be sustained by a variety of means, including electrical, electromagnetic and chemical; they may find application in plasma torches, light sources, etc.

Abstract: An apparatus for producing a stable, high pressure plasma column with long length, and high axial uniformity. Rotating a gas-filled tube about an horizontal axis creates a vortex with minimal, or no shear flow. Such a vortex provides a stable equilibrium for a central column of high temperature gas and plasma when, for a given rotation speed, the centrifugal force dominates over the gravitational force inside the smallest radial dimension of the containment envelope. For gas pressures sufficiently high that the particle mean free path is short compared with the thickness of the gas layer between the central plasma column and the wall, thermal transport across this sheath layer is small and its temperature is low. High pressure discharges inside a rotating envelope may be sustained by a variety of means, including electrical, electromagnetic and chemical; they may find application in plasma torches, light sources, etc.

Abstract: An apparatus for producing a stable, high pressure plasma column with long length, and high axial uniformity. Rotating a gas-filled tube about an horizontal axis creates a vortex with minimal, or no shear flow. Such a vortex provides a stable equilibrium for a central column of high temperature gas and plasma when, for a given rotation speed, the centrifugal force dominates over the gravitational force inside the smallest radial dimension of the containment envelope. High pressure discharges inside a rotating envelope may be sustained by a variety of energy sources, including electrical, electromagnetic and chemical; they may find application in plasma torches, light sources, etc.

Abstract: A grating spectrometer employing digital control of an oscillating component (a mirror) and phase-locked digital recording of the intensity profile within the narrow spectral domain defined by an oscillation frequency. Flexible choice of oscillation frequency permits measurement in a quiet region of the noise spectrum. Reference waveforms acquired with the same insturment can be stored and later used to deconvolute a more complex spectrum. The use of multiple detector/slit combinations along a Rowland circle makes the spectrometer sensitive to specific atomic elements.

Abstract: A spectrometer that determines a spectral correlation between an optical signal and a reference spectra over a broad spectral range while maintaining a relatively high resolution. The spectrometer uses a mask that has high resolution slits at wavelengths corresponding to the reference spectra. Relative oscillatory movement is induced between the mask and the imaged spectra of the optical signal is induced and the light passing through the slits is collected by an optical sensor. A lock-in amplifier monitors a signal from the optical sensor as well as a signal representative of the oscillatory movement and determines a correlation between them.

Abstract: A spectrometer provides a substantially simultaneous electronic output over a broad spectral range while maintaining a relatively high resolution. The spectrometer uses a fiber-optic transformer having an arcuate one-dimensional input region, associated with the image plane of a Rowland circle, and produces a rectangular two-dimensional output image, for illuminating the active area of a two-dimensional CCD sensor.