<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>X</mml:mi> </mml:math> -Point Target Radiator Regime in Tokamak Divertor Plasmas
K. Lee, C. Theiler, M. Carpita, O. Février, A. Perek, M. Zurita, D. Brida, Richard Ducker, G. Durr-Legoupil-Nicoud, B.P. Duval, S. Gorno, D. Hamm, D.S. Oliveira, F. Pastore, M Pedrini, H. Reimerdes, L. Simons, E. Tonello, K. Verhaegh, Y.S. Wang, C. Wüthrich, the TCV Team and the EUROfusion Tokamak Exploitation Team
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.