Confinement properties in the large aspect ratio, full tungsten environment of the WEST tokamak

V Ostuni (1, 2) , J Morales (1, 2) , C Bourdelle (1, 2) , J-F Artaud (1, 2) , P Manas (1, 2) , R Dumont (1, 2) , N Fedorczak (1, 2) , M Goniche (1, 2) , P Maget (1, 2) , Y Sarazin (1, 2)

1 CEA - Commissariat à l'énergie atomique et aux énergies alternatives
2 IRFM - Institut de Recherche sur la Fusion par confinement Magnétique

WEST is a metallic tokamak operating in L mode since December 2016. Its specificities are an aspect ratio value of 5-6 and the inner wall covered with tungsten tiles plus ITER like PFU on lower divertor. Its plasmas are dominantly electron heated (ICRH and LHCD) and torque free (no NBI). In this work, we analyze extensively the database of WEST plasmas to characterize the operational domain, based on plateaus of quasi-steady phases of power and current. In WEST database, 20% of the detected plateaus are affected by a rapid collapse of the central electron temperature or do not reach more than 1.5 keV at the core. Since reaching plasmas with enhanced stability is fundamental to obtain high tokamak performances, the core radiative collapse is modelled using RAPTOR to understand the causality leading to colder plasma core.

Domaines: Physique [physics]

V Ostuni, J Morales, C Bourdelle, J-F Artaud, P Manas, et al.. Confinement properties in the large aspect ratio, full tungsten environment of the WEST tokamak. 25th Joint EU-US TTF Meeting - EU-US Transport Task Force, Sep 2021, E-Conference, United Kingdom. . ⟨cea-03349956⟩