Flat-top plasma operational space of the STEP power plant

• DOI: 10.1088/1741-4326/ad6ea2
• Publication Date: 2024-08-13T22:51:30Z
• Authors: E. Tholerus; F.J. Casson; S.P. Marsden; T. Wilson; D. Brunetti; P. Fox; S.J. Freethy; T.C. Hender; S.S. Henderson; A. Hudoba; K.K. Kirov; F. Koechl; H. Meyer; S.I. Muldrew; C. Olde; B.S. Patel; C.M. Roach; S. Saarelma; G. Xia
• Keywords: Fusion power; Auxiliary power unit; Plasma parameter

Abstract STEP is a spherical tokamak prototype power plant that being designed to demonstrate net electric power. The design phase involves the exploitation of plasma models optimise fusion performance subject satisfying various physics and engineering constraints. A modelling workflow, including integrated core modelling, MHD stability analysis, SOL pedestal coil set free boundary equilibrium solvers, whole design, has been developed specify parameters develop viable scenarios. model JETTO used individual flat-top operating points satisfy imposed criteria for within operational Key such as normalised beta, Greenwald density fraction, auxiliary radiated have scanned scope space derive collection candidate non-inductive points. assumed heating current drive either from electron cyclotron (EC) systems only or combination EC Bernstein waves. At present stages transport there large uncertainty in overall confinement relevant parameter regimes. For each two scenarios, based on different assumptions, totalling four lower assumption generally suggests high-density, high regimes, whereas higher would allow access broader regime while maintaining target performance.