Conveners
X-point and other Radiator Regimes
- Felix Reimold (Max Planck Institute for Plasma Physics, Greifswald, Germany)
X-point and other Radiator Regimes
- Felix Reimold (Max Planck Institute for Plasma Physics, Greifswald, Germany)
X-point and other Radiator Regimes
- Felix Reimold (Max Planck Institute for Plasma Physics, Greifswald, Germany)
The exhaust of power as well as the He particles produced by the fusion reactions in a nuclear fusion reactor remains one of the key challenges. As a possible solution for this problem Alternative Divertor Configurations (ADCs) have been studied in many tokamaks worldwide, like TCV \citep{Reimerdes_2017,Theiler_2017}, DIII-D \citep{Soukhanovskii_2018}, NSTX \citep{Soukhanovskii_2016} and...
The X-point radiator (XPR) plasma regime displays favorable properties with regard to power exhaust in tokamaks. An H-mode-like confinement quality, a detached divertor, and the suppression of type-I ELMs are achieved simultaneously. XPR scenarios may also pave the way for more compact and cheaper divertor solutions, as demonstrated on ASDEX Upgrade [3]. The XPR regime was realized on...
It has now been demonstrated experimentally in several research tokamaks that a controlled X-point radiator (XPR) under H-mode conditions can not only provide for a fully detached divertor, but also yield a naturally more ELM-stable regime [1-3]. This is therefore a rather attractive scenario for reactors, especially those operating with tungsten (W) divertors, including ITER, since it is well...
An X-point radiator (XPR) features a stable, cold, and dense plasma surrounded by a highly radiative mantle above the X-point inside the confined region, providing a dissipated power fraction larger than 90%, fully detached divertor targets, and ELM mitigation, and is considered a potential solution for the power exhaust challenge in future fusion reactors. The XPR-like regime is observed in...
A major issue for next step devices is the control of plasma wall interaction, both for keeping the material erosion at reasonable level as well as for avoiding core contamination by high Z impurities and consequently the reduction of plasma performances. In this respect, WEST experiments supported by numerical modeling are particularly relevant to progress in the physical understanding of the...
The X-point radiator (XPR) regime, observed in the WEST tokamak, is characterized by the appearance of a stable radiative ring above the X-point with sufficient nitrogen seeding. The transitions from high-recycling regime to the XPR regime usually happen within very short time. XPR regime can significantly mitigating the heat load at the divertor target while maintaining core plasma...
Experiments on the TCV tokamak have enabled the identification and detailed characterization of a novel X-point radiator regime, the X-point target radiator (XPTR) [1], which forms at a secondary X-point embedded along the outer divertor leg in the X-point target divertor geometry [2]. Unlike the conventional X-point radiator regime, the XPTR spatially decouples the radiator from the confined...
This presentation summarises the first attempts to develop an X-point radiator (XPR) regime on MAST-U. The XPR, a localised radiating structure near the magnetic X-point, is a promising power exhaust solution for future fusion reactors. While XPR regimes have been demonstrated on most operating devices, MAST-U remains one of the last major tokamaks yet to access this regime. The work presented...
X-point radiation experiments in the DIII-D tokamak explored stable X-point radiating (XPR) conditions with mitigation of edge localized modes (ELMs) potentially relevant to steady-state divertor operation in future devices while collecting detailed local measurements of plasma parameters and species-resolved radiating emissivities for model validation. Regimes with X-point radiation [1] are...
Radiative divertor detachment with impurity seeding is considered one of the most promising means for mitigating particle and heat fluxes on the divertor target. To measure the impurity radiation distribution, a tangentially viewing camera system for lower divertor plasma observation has been developed and installed on EAST. A reconstructed 2D distribution of N II line radiation is obtained...
