Speaker
Christian Vorpahl
(Port Plugs & Diagnostics Integration Division)
Description
Numerous plasma-near mirrors of optical diagnostics of ITER require protection from erosion and deposition caused by impinging energetic particles. This is achieved by approximately 60 individual Diagnostic Shutters, rather simple mechanical devices which obstruct the mirror’s sight towards the plasma when the diagnostic is not in use. If a shutter fails to operate, so does the respective diagnostic.
Shutters shall operate in vacuum under high thermal fluxes over 20 years without maintenance. Their components will experience neutron fluxes of up to 101414/cm22s with energies up to 14 MeV. As these conditions are unprecedented even on fusion devices, standard engineering solutions are ruled out, and qualification R&D efforts are extensive.
As every shutter is part of the diagnostic it protects, the design tasks are widespread among Domestic Agencies and their suppliers. However, the obvious synergy potential of these highly resembling systems calls for coordination of design and prototyping to save effort, but also consistently handle risk.
Therefore, a coordination strategy for all ITER shutters was implemented at IO. An extensive collection of experience on shutters from 14 fusion devices was performed, including failure reports. This experience is summarized in the present work.
For the first time, the state-of-the-art of shutter design with respect to fusion diagnostics is thereby defined. The lessons learnt are assessed with respect to their applicability for ITER. Furthermore, potentially design-driving environmental effects such as high-temperature creep and irradiation-induced embrittlement are recalled and theoretically evaluated against the specific ITER operational conditions.
The findings of both assessments are put into context with the current designs of all ITER shutters. In a next step, these are reviewed with particular emphasis on possible synergies between different shutter systems.
Finally, recommendations on design and necessary R&D, such as common prototyping and the development of generic components are given.
Co-authors
Alexander Zvonkov
(Diagnostics, ITER Russia, Pl. Akademika Kurchatova, 1, Moscow, Russian Federation)
Andrei Khodak
(Diagnostics, US-ITER, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830, United States)
Andrey Alekseev
(Diagnostics, ITER Russia, Pl. Akademika Kurchatova, 1, Moscow, Russian Federation)
Changrae Seon
(Diagnostics team, ITER Korea, ITER Korea, National Fusion Research Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 34133, South Korea)
Christian Vorpahl
(Port Plugs & Diagnostics Integration Division, ITER Organisation, St Paul Lez Durance, France)
Eiichi Yatsuka
(Naka Fusion Institute, Japan Atomic Energy Agency, 801-1 Mukoyama Naka, Ibaraki 311-0193, Japan)
Eugene Mukhin
(Diagnostics, ITER Russia, Pl. Akademika Kurchatova, 1, Moscow, Russian Federation)
Frederic Le Guern
(Diagnostics, Fusion for Energy, c/ Josep Pla, nº 2, Torres Diagonal Litoral, Edificio B3, 08019 Barcelona, Spain)
Jonathan Klabacha
(Diagnostics, US-ITER, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830, United States)
Mark Smith
(Diagnostics, US-ITER, 1055 Commerce Park Dr #1, Oak Ridge, TN 37830, United States)
Shakeib Arshad
(Diagnostics, Fusion for Energy, c/ Josep Pla, nº 2, Torres Diagonal Litoral, Edificio B3, 08019 Barcelona, Spain)
Sunil Pak
(Diagnostics team, ITER Korea, ITER Korea, National Fusion Research Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 34133, South Korea)
Takaki Hatae
(Naka Fusion Institute, Japan Atomic Energy Agency, 801-1 Mukoyama Naka, Ibaraki 311-0193, Japan)
