Spectroscopic measurements of radial distribution of electron density and temperature in a plasma
| Autor: | Leonardo Placentino, Giuseppe Tondello, Enrico Colombo, Enrico Paganini, Enrico Emolumento, Vieri Piemontese |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | Pure and Applied Optics: Journal of the European Optical Society Part A. 5:471-494 |
| ISSN: | 1361-6617 0963-9659 |
| Popis: | A set of spectroscopic measurements in a high-voltage circuit breaker has been performed in order to evaluate the radial distribution of the electron density and temperature in a section of the arc, and their time evolution in the last half-period of the current before the arc extinction. The measurements have been made at various values of effective current and at two different distances from the fixed electrode. The arc sizes have also been evaluated. A spectroscopic device has been built based on two very fast bi-dimensional CCD detectors, providing observations in the visible range with simultaneous spectral resolution of 0.1 nm, spatial resolution lower than 0.5 mm and time resolution down to with a frame every 0.5 ms over a total observing time of about 10 ms. The lines S II 5453.8 A and F I 6348.5 A have been observed and the Abel inversion has been performed. By measuring the intensity ratio of the two lines, the temperature has been measured and through their Stark broadening the density has been evaluated. The experimental set-up is shown, the arc modelling and the procedure used to obtain the results are presented, the equations are discussed and their physical conditions of validity, particularly the LTE and the condition of small optical depth, are verified. The main results achieved, concerning the arc size, the maximum values of electron density and temperature, at various test currents, and their radial profiles in a section of the arc, are reported. |
| Databáze: | OpenAIRE |
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