On the possibility to use the ultra high frequency resonator for measuring products of plasma facing components erosion under high-energy-impact in fusion devices

• Published in: Plasma devices and operations Vol. 11; no. 4; pp. 229 - 236
• Main Authors: Skibenko, A. I., Fomin, I. P., Pinos, I. B., Podoba, Yu. Ya, Voitsenya, V. S.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.12.2003
• Subjects: Dust; Frequency shift; Graphite; Particle of substance; UHF resonator
• ISSN: 1051-9998; 1029-4929
• DOI: 10.1080/10519990310001640920

The method for measuring a material eroded from surfaces of inner elements subjected to strong plasma impact in a fusion reactor and falling down to the bottom of a vacuum chamber in the form of microparticles was suggested and approved. An open ultra high frequency (UHF) resonator fabricated of two spherical mirrors was used as a measuring tool. The working frequency of 37 GHz was sweeped linearly in the frequency range of 60 MHz. Single particles of a substance (teflon, paraffin, graphite) or fine-dispersed graphite dust falling free down through the central part of the resonator caused a decrease of the resonance amplitude and shift of its eigenfrequency. Experiments with controlled properties (specific density, size, and permittivity) of substances, such as teflon or paraffin, showed that using such a resonator these characteristics can be measured with a reasonable accuracy. The effect of external magnetic field and background plasma can be taken into account.