Integrated Microwave Atmospheric Plasma Source (IMAPlaS): thermal and spectroscopic properties and antimicrobial effect on B. atrophaeus spores

R. Bussiahn¹, R. Gesche² , S. Kühn² and K.-D. Weltmann¹

¹ Leibniz Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, 17489 Greifswald, Germany
² Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany

Published in:
Plasma Sources Sci. Technol., vol. 21, no. 065011 (2012).
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Abstract:
The Integrated Microwave Atmospheric Plasma Source (IMAPlaS) operating with a microwave resonator at 2.45 GHz driven by a solid-state transistor oscillator generates a core plasma of high temperature (T >1000 K), therefore producing reactive species such as NO very effectively. The effluent of the plasma source is much colder, which enables direct treatment of thermolabile materials or even living tissue. In this study the source was operated with argon, helium and nitrogen with gas flow rates between 0.3 and 1.0 slm. Depending on working gas and distance, axial gas temperatures between 30 and 250 °C were determined in front of the nozzle. Reactive species were identified by emission spectroscopy in the spectral range from vacuum ultraviolet to near infrared. The irradiance in the ultraviolet range was also measured. Using B. atrophaeus spores to test antimicrobial efficiency, we determined log 10-reduction rates of up to a factor of 4.

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