The TCV tokamak contributes to the development of nuclear fusion energy with proof-of-principle experiments and by validating models that are used to predict reactor performance. As part of the Swiss Roadmap for Research Infrastructures, the SPC is upgrading TCV to test a tightly baffled, long-legged divertor (TBLLD), a novel concept designed to enhance power exhaust capabilities with minimal...
The detached divertor regime has been demonstrated to be effective in mitigating steady-state particle and heat loads to divertor plasma-facing components in current devices and is a key aspect of operating regimes in future high power devices including ITER [1]. Alternative divertor configurations, such as the Super-X [2] offer advantages to conventional divertors such as a wider operating...
Negative Triangularity (NT) configurations exhibit higher energy confinement compared to the conventional Positive Triangularity (PT) configurations. Experiments on TCV [1] and DIII-D [2] have shown that NT L-Mode plasmas can achieve confinement comparable to H-mode, with $\beta_N$ up to 2.8 (2 in stationary state) demonstrated in TCV. This suggests the potential for high-confinement L-Mode...
In the first phase of exploitation of the Divertor Tokamak Test facility (DTT) different magnetic configurations and scenarios will be study with the aim to identify the most promising. The first divertor will therefore have to be robust and flexible, able to withstand high thermal loads for long pulses and to accommodate strike points located at various positions according to the different...
The Tokamak Divertor serves as a critical component within fusion reactors, essential for managing plasma exhaust and ensuring the stability and efficiency of nuclear fusion devices. It effectively remove and contain particles such as helium ash, fuel impurities and heat-dissipating particles, thereby enhancing plasma stability and extending reactor lifespan. A Tungsten base alloy divertor...
Understanding the mechanisms that govern heat and particle transport in the divertor region is critical for the design and operation of future fusion reactors. Turbulent cross-field transport plays a key role in determining the heat flux distribution at divertor targets, affecting both the peak heat load and the overall power exhaust scenario. A key metric for characterizing heat flux...
The DIVertor GAs Simulator (DIVGAS), developed by the Vacuum group at the Karlsruhe Institute of Technology (KIT), offers a powerful and reliable framework for optimizing and evaluating divertor design – a critical component in advancing fusion technology in next-generation fusion reactors. The DIVGAS framework features two powerful modules – a deterministic one and a stochastic one – allowing...
In the recent experimental campaign OP2.2, the neutral gas pressures previously measured in the subdivertor of Wendelstein 7-X could be confirmed and improved with subdivertor neutral gas pressures of 3$\cdot10^{-3}$\,mbar routinely reached in standard as well as high iota configuration. Those two magnetic field configurations differ by the number and positions of the edge magnetic islands and...
A future nuclear fusion reactor demands its plasma-facing components (PFCs) to be able to handle the generated heat fluxes. For the divertor to survive continuous operation, mitigating the incoming heat loads is essential [1]. An established approach for reducing the heat loads is by injecting low to medium-Z impurities [2], which stimulates radiation emission in the plasma edge region....
Power exhaust remains a key challenge for tokamak-based nuclear fusion, requiring accurate prediction and control of heat loads on divertor targets. Strategies such as increasing divertor closure and exploring alternative divertor configurations (ADCs) are central to mitigating target heat and particle fluxes. The Tokamak à Configuration Variable (TCV) [1] is uniquely equipped to investigate...
Design structure matrices (DSMs) represent the connections between elements composing a system. In fusion, they are used to visualize the dependencies between various plasma variables, processes, states, and events and they serve as a basis for synthesizing supervisory controllers. A DSM representing the existence and absence of these plasma relations has been constructed after strong...
Liquid metal (LM) has been conceptualized for use as plasma-facing component (PFC) in future fusion devices [1]. Being accessible to self-repairing and self-replenishment, thanks to the nature of the liquid phase, has been attractive for being applied in future long-run but less-maintenance fusion devices. This encourages the promotion of such research field throughout the years [2-5]. Despite...
UEDGE simulations of a “chimney” divertor, utilizing mid-leg pumping upstream of the divertor target along the outer baffle, predict the formation of a stable radiation front between the pumping plenum and X-point. The mid-leg pumping plenum is proposed as an engineering solution to stabilize the detachment front location downstream of the X-point, maintaining a hot X-point ($\rm T_{e,Xpt}$ ~...
The divertor, being the most heavily loaded component of a magnetic confinement fusion device, must withstand high heat flux (HHF) loads and intense neutron irradiation during fusion operation. Established designs for plasma-facing components (PFCs) in the divertor region comprise a combination of monolithic tungsten (W) armor blocks and a copper (Cu) alloy heat sink. One established design is...
The huge heat load onto divertor is a crucial issue in fusion reactor. While the radiative impurities are necessary for achieving divertor detachment especially for the future tokamak [1], it is also found to have essential effects on ELM control [2]. It implies the possibility of simultaneous control of the transient and steady-state heat load by impurity seeding. Therefore, it is necessary...
A large driver of future fusion reactor size is the need to handle transient events that could potentially cause re-attachment, which pushes the capabilities of conventional divertors [1]. Liquid metals are an attractive solution to transients due to vapor shielding [2] whereby the temperature of the plasma facing component (PFC) becomes clamped even at excessive plasma heat fluxes, such as...
Due to its position and functions, the divertor has to sustain very high heat flux arising from the plasma (up to 20 MW/m2), while experiencing an intense nuclear deposited power, which could jeopardize its structure and limit its lifetime. Therefore, attention has to be paid to the thermal-hydraulic design of its cooling system. It is necessary to take effective cooling methods from the...
