29th Symposium on Fusion Technology (SOFT 2016)

I5.2 WEST Project status and Research plan towards ITER risk mitigation

9 Sep 2016, 09:10

40m

Forum Hall 2nd floor (Prague Congress Centre)

Board: 2

Oral I5.2 E. Tsitrone

Speaker

E. Tsitrone (CEA)

Description

The WEST project is targeted at minimizing risks for ITER divertor procurement and operation. It consists in implementing an actively cooled tungsten divertor for testing the ITER divertor technology under tokamak conditions in Tore Supra. The present paper gives an overview of the project status, and describes the main lines of the associated research plan. As far as the project is concerned, the first assembly phase has been completed in spring 2015 (dismantling of the existing internal components and installation of the outer protection panels). At present, the installation of the divertor coils is underway. The divertor supporting structure has been manufactured and implemented in the machine. Brazing of the coils copper conductors is presently ongoing inside the vessel. The divertor coils power supplies have been produced in China in collaboration with the South-Western Institute of Physics, for delivery in Cadarache in spring 2016. 3 new CW ELM-resilient ICRH antennas are being manufactured in China in collaboration with the institute of Plasma Physics of the Chinese Academy of Sciences, with a trial assembly of the first antenna planned in China in spring 2016. The procurement of the ITER-like divertor plasma facing units (PFUs), using the ITER tungsten monoblock technology, is underway in collaboration with the European and Japanese Domestic Agencies in charge of providing ITER divertor targets. Prototypes from ITER potential suppliers are in preparation and planned to be tested in the WEST tokamak environment. Series production will be launched afterwards and will not be available before 2018. For the other high heat flux plasma facing components, tungsten-coated technologies have been qualified on various substrates (CuCrZr, CFC, and Fine Grain Graphite). In particular, inertial graphite PFUs with tungsten coating from the Romanian National Institute for Laser, Plasma and Radiation Physics have been manufactured in order to complement the ITER-like PFU on the WEST lower divertor for the first phase of operation. Roughly 1/3 of the upper and lower divertor tungsten coated PFU have been received in Cadarache. The overall diagnostic layout has been finalized, with key diagnostics being implemented for monitoring of the divertor heat loads, plasma edge conditions and tungsten sources and transport (Langmuir probes, infrared PFC monitoring, calorimetry, visible spectroscopy …). The data acquisition systems, the control, data access and communications (CODAC) is also being upgraded in partnership with the Institute for Plasma Research in India. A new plasma control system prototyping ITER requirements is being developed in collaboration with the Max Planck Institute for Plasma physics in Germany. First plasma is targeted for fall 2016. WEST provides relevant plasma conditions for validating PFU technology and exploring high heat flux operation and high particle fluence plasma wall interactions with tungsten. WEST operation is phased, to make the best use of the WEST ITER like PFU as they become available. In phase 1, WEST lower divertor will be operated with a mix of actively cooled ITER like PFU and inertial tungsten coated divertor start up elements. In this phase, plasma operation will be limited in time by the inertial divertor elements (typically ~5-10 s at high power). In phase 2, the full actively cooled ITER like divertor will be implemented, allowing long pulse operation up to 1000 s. High priority research areas of the PFU testing program will be described (focus on power handling performance of the ITER PFU during phase 1, high particle fluence interactions during phase 2). The WEST platform is open to ITER partners, and an international call for proposals has been send in January 2016. The paper will present an overview of the experimental program as derived from the call process.