Title
Development of vacuum RF feeder lines for front-end mirrors plasma cleaning in ITER optical diagnostics
Author
Ushakov, A.
Stephan, U.
Steinke, O.
Verlaan, A.L.
de Bock, M.
Maniscalco, M.P.
Verhoeff, P.
Publication year
2020
Abstract
The Visible Spectroscopy Reference System (VSRS.55.E6) is going to be one of the first optical diagnostics in the ITER tokamak. The VSRS front-end part shall contains the 100 mm diameter first mirror (FM). The FM is expected to experience contamination with beryllium and tungsten. Levels of contamination on the order of 10 nm degrade the FM optical performance. In the VSRS, a high-frequency RF-discharge-based plasma cleaning will be implemented to maintain or restore the optical performance. The system also contains more than 30 m long RF power feeding components, partly in vacuum, and a number of interfaces. In the present report, we analyze the design requirements for the RF electrical circuit with a plasma load to prevent power loss, parasitic discharges and vacuum arcing. The proposed analysis is useful for long RF circuits for plasma cleaning of front-end optics.
Subject
Thermonuclear fusion
Fusion reactors
Gas discharge devices
Ionization
Plasmas
Dielectric breakdown
Radio-frequency
Plasma devices
Etching
Surface treatment
High Tech Systems & Materials
Industrial Innovation
To reference this document use:
http://resolver.tudelft.nl/uuid:39677df6-daa0-4356-8c81-dfed05c97c24
TNO identifier
959531
Publisher
IEEE
Source
29th International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV, virtual from Padova, Italy, 26-30 September 2020
Document type
conference paper