Fig. 1: The MAST-U tokamak, its divertor configurations and detachment.

a, MAST-U vessel with the gas valve and MWI44 locations indicated, the transport of energetic core particles towards the outer divertor targets is indicated by the red arrows. b, Cross-section of the lower divertor, using radial (R) and vertical (Z) coordinates, showing the wall, magnetic coils and the magnetic equilibria of the Super-X, Elongated and Conventional divertor configurations. c, Schematic of an attached divertor (left) with volumetric impurity radiation and an ionization region located at the strikepoint (Ltar = 0), a detached (Ltar > 0) divertor (right) absorbs the incoming heat flux by forming a neutral cushion, massively reducing the strikepoint heat flux. Credit: background image in a, United Kingdom Atomic Energy Authority.