Abstract
Fusion plasma regimes with a strongly radiating magnetic X point are promising candidates to tackle the outstanding power exhaust challenge in reactor-scale devices. In this Letter, we report on a new type of X-point radiator, the XPTR (X-point target radiator), produced by a secondary X point placed well away from the confined plasma. This XPTR features strongly facilitated detachment access and significantly reduced sensitivity of the radiative front position near the secondary X point. Consistent with a reduced analytical model, the physical origin of X-point radiation is rooted in its magnetic geometry, irrespective of whether the field lines are closed or open. The results presented open up a class of novel power exhaust concepts where radiative edge cooling can be robustly avoided during divertor detachment.
| Original language | English |
|---|---|
| Article number | 185102 |
| Journal | Physical Review Letters |
| Volume | 134 |
| Issue number | 18 |
| DOIs | |
| State | Published - May 9 2025 |
Funding
We thank M. Bernert and U. Stroth for insightful discussions. The careful reading of the manuscript by I. Furno, R. Karimov, and H. Sun is gratefully acknowledged. This work was supported in part by the Swiss National Science Foundation. This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research, and Innovation (SERI). TCV Team and EUROfusion Tokamak Exploitation Team authors [56]. We thank M. Bernert and U. Stroth for insightful discussions. The careful reading of the manuscript by I. Furno, R. Karimov, and H. Sun is gratefully acknowledged. This work was supported in part by the Swiss National Science Foundation. This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research, and Innovation (SERI).