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Improved measurement of the electron temperature of a low density shock-heated argon plasma by means of microwaves

Published online by Cambridge University Press:  13 March 2009

C. P. Schneider
Affiliation:
Messerschmitt-Boelkow-Blohm GmbH, Ottobrunn; Fachbereich Luft- und Raumfahrttechnik, Hochschule der Bundeswohr München, Neubiberg, West Germany

Abstract

The determination of electron temperature of a low density shock-heated argon plasma (3 Torr ≤ p1 ≤ 10 Torr, 5500 °K ≤ 9500 °K) by means of microwave diagnostics is improved with a test section which permits the simultaneous transmission of two microwave beams at different frequencies, and with two corrections applied to the measured attenuation of transmitted waves. The purpose of these corrections is to obtain the true attenuation due to wave power dissipation into the plasma, which is dependent on the electron temperature and density. The first correction takes into account the diffraction of waves by apertures of the test section and the wave defocusing by the plasma. The second correction considers the effect of wave beam bending due to the electron density gradient in the flow direction of the plasma. Both corrections diminish the measured wave attenuation. Consequently a lower ratio of attenuation to phase shift of transmitted waves is determined, which in turn yields lower values of electron collision frequency and electron temperature. This report describes the electron temperature evaluation technique in detail, and presents results. The electron temperature values obtained have a range of uncertainty of – 20 % and +10% only, with exceptions at the beginning of the test time. In most tests, the electron temperature is equal or lower by approximately 1000 °K in comparison with the heavy particle temperature.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1978

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References

REFERENCES

Abramowitz, M. & Stegun, I. A.. 1968 Handbook of Mathematical Functions, 5th ed. Dover.Google Scholar
Albini, F. A. & Jahn, R. G. 1961 J. Appl. Phys. 32, 75.CrossRefGoogle Scholar
Aro, T. O. & Walsh, D. 1967 Phys. Fluids 10, 1468.CrossRefGoogle Scholar
Bachynski, M. P., Cloutier, G. G. & Graf, K. A. 1963 RCA Victor Res. Rep. 7–80–26.Google Scholar
Bekefi, G. & Brown, S. C. 1961 Am. J. Phys. 29, 404.CrossRefGoogle Scholar
Chen, F. F. 1965 Plasma Phys. (J. Nuclear Energy) C7, 47.Google Scholar
Chen, F. F., Etievant, C. & Mosher, D. 1968 Phys. Fluids, 11, 811.Google Scholar
Cheung, A. Y. & Koopmann, D. W. 1972 Rev. Sci. Instr. 43, 1444.Google Scholar
Devoto, R. S. 1967 Phys. Fluids, 10, 354.Google Scholar
Foley, W. H. & Clark, J. H. 1973 Phys. Fluids, 16, 374.Google Scholar
Foley, W. H., Bader, J. B. & Nerem, R. M. 1973 Phys. Fluids, 16, 1630.CrossRefGoogle Scholar
Frost, L. S. & Phelps, A. V. 1964 Phys. Rev. 136, 1538.Google Scholar
Gobolic, P. A. & Nerem, R. M. 1973 Phys. Fluids, 16, 1622.Google Scholar
Groenig, H. 1975 Proceedings 10th International Shock Tube Symposium, Kyoto, p. 89.Google Scholar
Gutherie, A. & Wakerling, R. K. 1949 The Characteristics of Electrical Discharges in Magnetic Fields, ch. 2. McGraw-Hill.Google Scholar
Heald, M. H. & Wharton, C. B. 1965 Plasma Diagnostics with Microwaves. Wiley.Google Scholar
Huddlestone, R. H. & Leonard, S. L. 1965 Plasma Diagnostic Technigues. Academic.Google Scholar
Kamimoto, G. & Teshima, K. 1972 Kyoto Univ. C.P. 33.Google Scholar
Keller, J. B. 1957 J. Appl. Phys. 28, 426.CrossRefGoogle Scholar
Kleinvon, M. von, M. 1970 Optics. Wiley.Google Scholar
Koch, G. F. & Koelbig, K. S. 1968 IEEE Transact. AP16, 78.CrossRefGoogle Scholar
Kosow, I. L. 1963 Microwave Theory and Measurement. Prentice-Hall.Google Scholar
Laframboise, J. G. 1966 University of Toronto, Institute for Aerospace Studies Rep. 100.Google Scholar
Makios, M. 1966 Z. Naturforschg. 21a, 2040.CrossRefGoogle Scholar
Meinhold, G. 1968 BMWF Forschg. Ber. K 68–29.Google Scholar
Meinhold, G., Demmig, F. & Boetticher, W. 1974 Z. Naturforschg. 29a, 568.Google Scholar
Miyoshi, Y., Okamoto, Y., Uchida, T. & Fujita, J. 1967 Bull. Nagoya Inst. Techn. 19, 269.Google Scholar
Nakai, S., Kasuya, K. & Yamanaka, C. 1969 Physica, 41, 213.CrossRefGoogle Scholar
Robinson, L. C. & Sharp, L. E. 1963 Aust. J. Phys. 16, 439.Google Scholar
Schneider, C. P. & Groenig, H. 1972 Z. Naturforschg. 27a, 1717.Google Scholar
Schneider, C. P. & Park, C. 1975 Phys. Fluids 18, 869.Google Scholar
Schneider, C. P. & Exberger, R. J. 1977 NASA TM (to be published).Google Scholar
Schulz, G. J. & Brown, S. C. 1955 Phys. Rev. 98, 1642.Google Scholar
Singer, A. & Minkowski, J. M. 1973 Phys. Fluids, 16, 1176.CrossRefGoogle Scholar
Spitzer, L. 1962 Physics of Fully Ionized Gases. Interscience.Google Scholar
Stratton, J. A. 1941 Electromagnetic Theory. McGraw-Hill.Google Scholar
Sugimoto, S. & Nishida, M. 1972 Kyoto Univ. C.P. 35.Google Scholar
Sutton, G. W. & Sherman, A. 1965 Engineering Magnetohydrodynamics. McGraw-Hill.Google Scholar
Talbot, L. 1960 Phys. Fluids, 3, 289.CrossRefGoogle Scholar
Westphal, W. H. 1944 Physik. Springer.Google Scholar