UWAVS first mirror after long plasma cleaning: surface properties and material re-deposition issues
other
The PBS 55 GA Upper Wide Angle Viewing System (UWAVS) provides real time, simultaneous visible and IR images of the ITER diverter region via optical systems located in the upper port plugs of the ITER vacuum vessel. Optical performance is expected to deteriorate due to mirror contamination from plasma operations and imaging and temperature measurements are expected to reach unacceptable error levels In the UWAVS design, a first mirror (FM) cleaning system will be implemented to maintain restore optical performance. The feasibility of the RF plasma system was discussed in the previous reports. General Atomics (GA) leads the design of the UWAVS for ITER and has teamed with the Netherlands Organization for Applied Scientific Research (TNO) and Lawrence Livermore National Laboratories (LLNL) for the effort. This work was performed under the guidance of Princeton Plasma Physics Laboratory (PPPL). One of the important aspects of the plasma cleaning of the front-end mirrors (FM) in ITER UWAVS diagnostics is to understand possible long term damage due to the increased surface roughness and material deposition after multiple cleaning runs and how to minimize contamination due to the mirror and construction materials sputtering.
TNO Identifier
961360
Publisher
TNO
Source title
30th Symposium on Fusion Technology, SOFT 2018, 16-21 September 2018, Giardini Naxos, Italy
Collation
1 p.
Place of publication
Delft, The Netherlands
Files
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