Conveners
MCF
- G. Granucci (ISTP Milano - CNR)
MCF
- K. Crombé (Department of Applied Physics| Ghent University| Belgium)
MCF
- R. Coelho (Instituto Superior Tecnico)
MCF
- E. Wolfrum (Max Planck Inst. f. Plasmaphysik)
MCF
- H.-S. Bosch (EPS2019)
MCF
- C. Maggi (CCFE)
MCF
- R. Ding
MCF
- G. Pautasso
MCF
- R. Panek (Institute of Plasma Physics ASCR| Prague)
See the full abstract here:
http://ocs.ciemat.es/EPS2019ABS/pdf/I1.103.pdf
Energetic particles in the MeV range are ubiquitous in fusion devices [1]. On one hand, they can be suprathermal ions born from the fusion reactions or accelerated by ion cyclotron resonance heating. On the other hand, they can be runaway electrons (REs) that are spontaneously generated, for example, during a...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I2.101.pdf
The European roadmap for fusion energy has identified plasma exhaust as a major challenge towards the realisation of magnetic confinement fusion. To mitigate the risk that the baseline scenario with a single null divertor (SND) and a high radiation fraction adopted for ITER will not extrapolate to a DEMO reactor, the...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I2.102.pdf
This contribution reviews the currently applied wall conditioning methods in fusion devices with special emphasis on wall conditioning in the presence of a permanent magnetic field by applying RF discharges at the ion- and electron cyclotron range of frequencies (ICRF resp. ECRF). The review is built upon the results of...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O2.107.pdf
Tungsten (W) is a candidate for plasma-facing components in future fusion reactors like DEMO and already used in fusion experiments like JET-ILW and ITER, which is currently under construction. It is foreseen for wall areas of highest particle and power loads as it has high melting point and low physical sputter yield....
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O2.108.pdf
The initial current ramp phase of JET hybrid plasmas is used to optimise the q-profile to allow access to high beta and avoid MHD instabilities. Mixed protium-deuterium experiments have shown that the q-profile evolution during this phase varies systematically with average main ion isotope mass (Meff), as seen in Fig.1,...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O2.105.pdf
In magnetic confinement fusion, transport processes in the plasma edge region determine the power load onto the first wall materials which has to be minimized on the way towards a fusion power plant. While a main fraction of the power is transported parallel to the magnetic field lines to the divertor, a significant...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O2.109.pdf
Understanding the physics of the NTM onset and its suppression is a key problem in achieving controlled fusion. This requires better knowledge of the NTM threshold mechanism.
We solve the drift kinetic equation for the ion/electron response to the NTM magnetic perturbation, gi,e, assuming small magnetic island width,...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O2.106.pdf
Observations of divertor plasma turbulence in a series of experiments at the DIII-D tokamak has recently demonstrated the onset of parallel current and magnetic field fluctuations [1] with temporal parameters similar to those reported for the fluctuations of divertor plasma radiation intensity at the ASDEX Upgrade...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I2.104.pdf
In perturbative experiments, the power deposition profile is a crucial ingredient in the analysis of the (turbulent) transport [1, 2]. Typically, the deposition profile is calculated with a forward model and used for the computation of the transport [3, 4, 5]. We will show that allowing for uncertainties in the...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I2.105.pdf
Impurities are unavoidable in fusion plasmas and potentially highly problematic as they result in fuel dilution and radiative energy losses. Accurate predictions of fusion plasma performance, therefore, require a validated theoretical description of impurity transport, which in turn requires high accuracy measurements...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O2.112.pdf
Turbulent transport and its impact on ITER performance is investigated with the global flux-driven gyrokinetic code GYSELA. In that framework, a heat source, balanced by turbulent cross-field transport, determines the temperature profile. It is expected that the heat sink at the boundary and turbulence in the edge may...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I3.102.pdf
Two of the highest priorities in stellarator research are to verify the effects of orbit driftoptimization on the energy core confinement and to learn to prevent the accumulation of impurities in high-density plasmas. The basic framework for understanding energy and particle transport in these devices is neoclassical...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O3.101.pdf
The role of the radial electric field in high performance ion-root plasmas on Wendelstein 7-X (W7-X) is examined and compared with neoclassical predictions. In stellarator plasmas the neoclassical radial electric field (Er) is not intrinsically ambipolar, and is instead strongly tied to the plasma profiles. The...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O3.103.pdf
Energetic alpha particles generated by D-T fusion reaction and beam ions for plasma heating interact resonantly with shear Alfvén waves through damping process when their velocity is comparable with Alfvén velocity, resulting in excitation of energetic particle (EP)-driven MHD instabilities. Several types of EP-driven...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O3.105.pdf
High-density operation is an attractive target for a fusion reactor, as it raises the fusion power output. Stellarators are especially suitable for such a regime, because they are not restricted by the disruptive density limit and because their energy confinement is roughly proportional to the square root of the...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.101.pdf
We observe the formation of a high-pressure staircase pedestal (~16-20 kPa) in high beta p plasmas (beta p>1.5) in the DIII-D tokamak when large amplitude ELMs are suppressed using resonant magnetic perturbations (RMP). The pedestal cyclically transitions from a one-step structure to a wider two-step staircase...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.102.pdf
A strong, favourable isotope dependence of the energy confinement (tao E,th ~ A^0.4) has been found in Hydrogen (H) and Deuterium (D) JET-ILW type I ELMy H-modes, originating at the pedestal [1]. Also, the plasma density is systematically lower in H than in D plasmas [1]. This contribution examines the isotopic...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.104.pdf
In future fusion devices the collisionality Nue proportional to ne/Te^2 at the pedestal top will be very low, i.e. nue,pedtop ∼0.06 [1], due to the expected high temperature. On the other hand at the very edge it should be high, nu*e,sep ∼12, because a high separatrix density is necessary for efficient power exhaust....
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I4.104.pdf
The operation of future high-power density fusion reactors such as ITER and DEMO requires avoiding damaging plasma-facing surfaces and good core confinement. The former requirement necessitates operating in the detached divertor regime, and the latter is met by operating in the high confinement (H-) mode. Recent...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I4.106.pdf
Recent advances in shattered pellet injection (SPI) in the DIII-D tokamak have led to improved understanding of several critical issues for the ITER Disruption Mitigation System. Infrared thermography shows elevated thermal quench heat loads indicative of radiation asymmetries peaked near the injection source. However...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.105.pdf
A comprehensive diagnostic set compared against 2D modeling has provided new insight into energy transport and dissipation processes in detached plasmas and their scaling to future devices. Experiments and modeling reveal a detached divertor plasma dominated by plasma convection from the X-point towards the target....
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.110.pdf
Disruptions are one of the fundamental issues to be tackled in future tokamaks [1], due to significant eddy and halo currents in the conducting structures producing substantial electromagnetic forces and torques thanks to the interaction with the magnetic field. It is hence fundamental to have reliable modelling tools...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.111.pdf
The growing need for a fundamental understanding of complex MHD phenomena in diverted tokamaks requires the development of more sophisticated and highly demanding codes. The numerical MHD code JOREK-STARWALL is adapted and applied to the simulation of free-boundary instabilities. The investigation of this type of...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O4.108.pdf
In recent years the focus of tokamak fusion research onto power exhaust increased showing that first wall power load is one of the major challenges in realizing a power plant. Unmitigated divertor power loads in next step fusion devices like ITER are projected to exceed material limits making significant impurity...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/I5.102.pdf
Lausanne, Switzerland An extensive study of quasi-axisymmetric equilibria has been conducted, from which a highly promising magnetic field design has been found by exploiting ROSE (Rose Optimizes Stellarator Equilibria) [1] - an optimization code for 3D magnetic plasma equilibria. The results of this design study and...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O5.101.pdf
WEST is a full tungsten (W) superconducting tokamak with a major radius of 2.5 m, an aspect ratio of 5 and a nominal magnetic field of 3.7T. WEST programme aims at power exhaust studies on the ITER-like actively cooled tungsten divertor and at bulk plasma performance in discharges reaching 1000s.
So far up to 5.3 MW of...
See the full abstract here http://ocs.ciemat.es/EPS2019ABS/pdf/O5.102.pdf
Ion Cyclotron Resonance Frequency (ICRF) heating is one of the auxiliary heating methods which will be used in ITER. A detailed assessment of ICRF schemes available in the non-active phase of ITER operation was recently carried out [1]. As a result, the ICRF scenarios considered for ITER also include the so-called...
