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Microscopic and Spectroscopic Observations of Plasma Generation in the Microwave Heating of Powder Material

Akihiro MATSUBARA, Kazuya NAKAYAMA, Shigeki OKAJIMA and Motoyasu SATO¹⁾

Department of Engineering Science, Chubu University, 1200 Matsumoto, Kasugai, Aichi 487-8501, Japan

1)

National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan

(Received 6 May 2010 / Accepted 5 October 2010 / Published 4 November 2010)

Abstract

Structure formation during the plasma ignition was experimentally investigated under microwave irradiation of magnetite (Fe₃O₄) and graphite composite powder. It was found from microscopic images that there are stepwise structure formations: (i) a luminous layer, (ii) hotspots, (iii) flare like emissions, and (iv) a luminous body above the powder. The 1D-spatially resolved emission spectra show that the light of the luminous layer of (i) has CO bands, and the luminous body of (iv) has iron atomic spectra superimposed on the continuum spectrum. The structure formation indicates a process of plasma-material mixing through chemical reduction of the magnetite powder.

Copyright (c) 2010 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

structure formation, plasma-material interaction, microwave heating, emission spectrum, microscopic image

DOI: 10.1585/pfr.5.041

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References

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• [3] A. Matsubara et al., Plasma Fusion Res. 3, S1085 (2008).
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This paper may be cited as follows:

Akihiro MATSUBARA, Kazuya NAKAYAMA, Shigeki OKAJIMA and Motoyasu SATO, Plasma Fusion Res. 5, 041 (2010).