COMPASS Upgrade: a high-field tokamak for ITER- and DEMO-relevant research

Abstract

To achieve their goals, future thermonuclear reactors such as ITER and DEMO are expected to operate plasmas with a high magnetic field, triangularity and confinement. To address the corresponding challenges, the concept of the high-field ( $B_{\textrm{T}} \unicode{x2A7D}$ 5 T), high-current ( $I_{\textrm{P}} \unicode{x2A7D}$ 2 MA) COMPASS Upgrade tokamak was established, and the device is currently being constructed in Prague, Czech Republic. This contribution provides an overview of the priority physics topics for the future physics programme of COMPASS Upgrade, namely: (i) characterisation of alternative confinement modes, (ii) a power exhaust including liquid metals, (iii) operation with a hot first wall and (iv) the influence of plasma shape on pedestal stability and confinement. The main scenarios are presented, as predicted by METIS and FIESTA codes. Pedestal pressure and density are estimated using EPED, multi-machine semi-empirical scaling and a neutral penetration model. Access to detachment is estimated using a detachment qualifier.

Keywords

• tokamak
• H-mode
• liquid metal
• scenario development
• power exhaust