12 research outputs found
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Rutherford scattering of neutral atoms: a technique for measuring plasma ion temperatures. An analysis of the applicability to the central cell plasma of TMX
Rutherford scattering of neutral particles by plasma ions is examined as a method for determining plasma ion in the central cell fo the Tandem Mirror Experiment (TMX). When a scattering configuration, consisting of a 20-keV-, 10-A-deuterium neutral beam and an energy analyzer with a 1% resolution, is arranged such that only neutral particles scattered by plasma ions over an angle of 10/sup 0/ are accepted, central-cell ion temperatures in the 30- to 1000-eV range can be measured. The count rate registered by the detector(s) is estimated to be 2000 counts/ms. Consequently, good statistical accuracy and time resolution are attainable simultaneously. The results of the calculation are presented such that the scaling of the count rates and the energy broadening with scattering angle, neutral-beam energy, ion temperature, and plasma density can easily be deduced. Neutral helium beams are also considered; they have some advantages over deuterium beams. The background signal, caused by neutral particles entering the detector after two successive charge-exchange collisions, is examined and ways to completely eliminate this background are indicated
Two-wavelength HeNe laser interferometer
This paper presents an interferometer set-up in which two wavelengths are used simultaneously. This enables one to determine separately the phase shifts caused by changes in plasma density and by mechanical vibrations of the interferometer structure
A STUDY OF A WEAKLY IONIZED, ROTATING PLASMA
No abstract availabl
Analysis of blister formation in spatial ALD Al2O3 for silicon surface passivation
Aluminum oxide (Al2O3) thin films yield excellent surface passivation of silicon solar cells. However, unwanted delamination, known as blisters, can occur upon annealing. In this research, blistering is linked to hydrogen diffusion in the bulk. Results reveal competition between diffusion lateral and perpendicular to the interface. Therefore, large blister densities coincide with small blister diameters and vice versa. The total blister volume, however, is independent of blister size distribution, but linked to hydrogen diffusion from the Al2O3 bulk. The blister volume was determined using AFM measurements, which show identical blister shapes for different blister sizes. Additionally, no direct relationship between blister formation and minority carrier was found
Experimental observations and model calculations of impurity radiation in a plasma gun compact torus experiment
Several types of radiation measurements were performed on the Beta II compact forms experiment. Among these are time integrated spectra ranging in wavelength from the vuv to the uv, time resolved bolometer measurements of radiation from the x-ray to the infrared, and time and wavelength resolved measurements of certain spectral lines. It is difficult to relate any one of these measurements to plasma parameters of interest such as temperature, density, or impurity content. In this report we compare the results of these, and other measurements with two simple models of the power balance in the plasma in order to estimate the effect of carbon and oxygen impurities on plasma lifetime
Field emission of monoenergetic spin-polarized electrons
Baum G, Kisker E, Mahan AH, Raith W, Reihl B. Field emission of monoenergetic spin-polarized electrons. Appl.Phys. A. 1977;14(2):149-153