1. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 1 Although a sound progress has been achieved in the field of first mirror investigation, there is a number of open questions. These questions need to be addressed urgently. ► Materials, locations and shapes of mirrors are yet to be determined; ► Mirror research is presently still in the frames of fundamental investigations and is relatively weakly related to the ITER-specific diagnostics; ► Dedicated modeling of existing experiments is lacking. Predictive modeling is missing. ► Uncertainties related with ITER design and performance. (e.g. limiter phase of ITER operation, diagnostics issues: distance to the plasma is defined voluntarily for various diagnostics). The R&D decisions have to be made soon. Background

2. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 2 General strategy: Clearly define the issues influencing the mirror performance and concentrate the main efforts on resolving them. Current research: modeling and experiments: ► Problems and tasks for modeling should be identified and supplied to the modeling community. Proposal: impurity transport in/towards the diagnostic systems, erosion and deposition patterns on the mirrors and impact on their performance; ► More diagnostic-related mirror research: experiments with prototypes and mock-ups of ITER diagnostic systems should have the highest priority; ► Specific requirements for the mirrors of the respective diagnostics: reflectivity, planarity, polarization requirements should be taken into account. ► Closer collaboration with diagnostic people; ► Intensify the collaboration with PWI community. Proposed agenda

3. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 3 General issues: Neutron effects We need a database of the neutron effects (transmutation) on the mirror (and wall) materials. ► Action: coordinated work with Radiation effects SWG (define a person); ► Possible action: storage of the publications on the SWG website. ► Ph. D. in IPP FZ Jülich Improved information exchange Re – structure the website: ► Introduce “Current Issues” section with sub-sections i.e. “Choice of mirror materials”, “Neutron effects”, “Impact of erosion and deposition on mirror performance”, “Deposition mitigation and mirror cleaning”, “R&D issues of the first mirrors” (with current work on mirror design, holders etc.)”, and post the selected publications, presentations, links and slides into it.

4. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 4 General issues Improved information exchange (continued): ► Introduce “Modeling of mirror performance” section (with the information or links, related to the first mirror modeling. ► Introduce “Future plans” section, so that Parties have an opportunity to share their ideas voluntarily and provide an aid in experimental planning. ► Diagnostic people: please update the table with mirror requirements for ITER. The table is available on the website at: https://tec.ipp.kfa-juelich.de/mirrorswg/https://tec.ipp.kfa-juelich.de/mirrorswg/ Username (case sensitive): ItpaUser; Password: IterMirror. Then ->”Diagnostic mirrors in ITER”->download the Word version of table and edit it. ► Forum(?).

5. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 5 Mirror issue in MSE diagnostics (proposed by V. Voitsenya)

6. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 6 Scheme for CXRS/MSE for central plasma and plasma at the periphery

7. ITPA-10, April 12, 2006. Moscow, Russia. A. Litnovsky et al. Discussion on first mirrors. Discussion on first mirrors 7 Rotation of the polarization angle of reflected light on the thickness of carbon film on Mo mirror for indicated incidence angles and wavelength 632.8nm as was measured by means of ellipsometry and calculated 0 5 10 15 20 25 30 01020304050 C film on Mo, =632.8nm Change of polarization angle, degrees Thickness of C film, nm 60 55 50 45