Abstract
We present a novel concept to tackle the power exhaust challenge of a magnetically confined fusion plasma. It relies on the prior establishment of an -point radiator that dissipates a large fraction of the exhaust power before it reaches the divertor targets. Despite the spatial proximity of the magnetic point to the confinement region, this singularity is far away from the hot fusion plasma in magnetic coordinates and therefore allows the coexistence of a cold and dense plasma with a high potential to radiate. In the compact radiative divertor (CRD) the target plates are placed close to this magnetic point. We here report on high performance experiments in the ASDEX Upgrade tokamak that indicate the feasibility of this concept. Despite the shallow (projected) field line incidence angles of the order of , no hot spots were observed on the target surface monitored by an IR camera, even at a maximum heating power of . And even with the point located exactly on the target surface and without density or impurity feedback control, the discharge remains stable, the confinement good (), hot spots absent, and the divertor in a detached state. In addition to its technical simplicity, the CRD scales beneficially to reactor-scale plasmas that would benefit from an increased volume of the confined plasma, more space for breeding blankets, smaller poloidal field coil currents, and—potentially—an increased vertical stability.
- Received 25 August 2022
- Accepted 2 March 2023
DOI:https://doi.org/10.1103/PhysRevLett.130.145102
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.
Published by the American Physical Society