Sideways forces on asymmetric tokamak walls during plasma disruptions

Yanovskiy, Vadim; Isernia, N.; Pustovitov, V. D.; Villone, F.

doi:10.1088/1741-4326/ac5fea

Cited by 6 publications

(2 citation statements)

References 49 publications

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“…To test this idea a dedicated modelling effort with the CarMa0NL code [57] that solves the evolutionary equilibrium of axisymmetric plasma in the presence of three-dimensional volumetric conductors has been performed [58]. It was found that the sideways force related to the vessel non-uniformity can be as high as 3 kN (for the mesh shown in figure 13(c)), which is 17% of the maximum vertical force for the same disruption.…”

Section: Sideways Forces On the Wall During Plasma Disruptionsmentioning

confidence: 99%

Overview of the COMPASS results ^*

et al. 2022

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COMPASS addressed several physical processes that may explain the behaviour of important phenomena. This paper presents results related to main fields of COMPASS research obtained in the recent two years, including studies of turbulence, L-H transition, plasma material interaction, runaway electron, and disruption physics:  Tomographic reconstruction of the edge/SOL turbulence observed by a fast visible camera allowed to visualize turbulent structures without perturbing the plasma. Dependence of the power threshold on the X-point height was studied and related role of radial electric field in the edge/SOL plasma was identified. The effect of high-field-side error fields on the L-H transition was investigated in order to assess the influence of the central solenoid misalignment and the possibility to compensate these error fields by low-field-side coils. Results of fast measurements of electron temperature during ELMs show the ELM peak values at the divertor are around 80% of the initial temperature at the pedestal. Liquid metals were used for the first time as plasma facing material in ELMy H-mode in the tokamak divertor. Good power handling capability was observed for heat fluxes up to 12 MW/m 2 and no direct droplet ejection was observed.  Partial detachment regime was achieved by impurity seeding in the divertor. The evolution of the heat flux footprint at the outer target was studied.  Runaway electrons were studied using new unique systems -impact calorimetry, carbon pellet injection technique, wide variety of magnetic perturbations. Radial feedback control was imposed on the beam.  Forces during plasma disruptions were monitored by a number of new diagnostics for vacuum vessel motion in order to contribute to the scaling laws of sideways disruption forces for ITER. Current flows towards the divertor tiles, incl. possible short-circuiting through PFCs, were investigated during the VDE experiments. The results support ATEC model and improve understanding of disruption loads.

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Section: Sideways Forces On the Wall During Plasma Disruptionsmentioning

confidence: 99%

Overview of the COMPASS results ^*

et al. 2022

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“…In tokamaks, the wall force due to disruptions may lead to a global horizontal displacement of the whole torus as reported in JET experiment [1]. Such wall force is called sideways force and it is related to asymmetric magnetic perturbations due to the symmetry-breaking plasma deformations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] or wall non-uniformity along the toroidal direction (asymmetric wall) [21,22]. In a Cartesian system of coordinates-where the z axis corresponds to the torus axis-sideways force corresponds to F x and F y components of the integral wall force while the remaining F z component is the vertical force.…”

Section: Introductionmentioning

confidence: 97%

Estimation of wall forces solely from magnetic measurements: an application to RFX-mod experiment

Abate,

Yanovskiy,

Bonotto

et al. 2023

Nucl. Fusion

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The estimation of integral wall force using solely magnetic measurement in RFX-mod experiment is presented. The vertical and sideways forces are directly obtained from the magnetic field measured outside the vacuum vessel. Several theoretical predictions related to tokamak are also verified for the reversed field pinch configuration. The contribution of different modes to the force is also considered and analyzed. This method of calculation would be relevant for future nuclear fusion reactors where magnetic measurements will be located only outside the vacuum vessel.

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Models for calculation of the sideways force due to the kink modes in tokamaks

Pustovitov

2022

Physics of Plasmas

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The solution of the sideways force problem is finally needed for the ITER project. The task became urgent when the extreme danger of such a force was perceived. The predictions were based on the so-called Noll's formula derived under some simplifications. One of them was the prescription of the plasma motion without testing its compatibility with the force balance condition. Later, an alternative approach has been proposed [D. V. Mironov and V. D. Pustovitov, Phys. Plasmas 24, 092508 (2017)], where the key element was the absence of an integral electromagnetic force on the plasma. Another important improvement was a proper treatment of the vacuum vessel wall. Now the extensions of the previously developed models leading to or supporting Noll's formula are proposed with the resistive wall reaction similarly incorporated. The main attributes of those approaches, the plasma displacements, are kept the same as in the original versions. Precisely, these are the plasma tilt or the [Formula: see text] kink mode. Two forces are calculated with such displacements: on the plasma and on the vacuum vessel wall. The former is shown to be far from zero in the analyzed cases, violating thereby the force-free condition. This does not happen when this constraint goes first. It becomes a selection rule for allowable perturbations. These roughly resemble the tilt and (1,1) mode but differ from them, which changes the result dramatically. The maximal force that can be produced by such kink-like modes compatible with the force balance cannot reach even one tenth of Noll's force. The quantitative comparisons of the competing models are provided.

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Sideways forces on asymmetric tokamak walls during plasma disruptions

Cited by 6 publications

References 49 publications

Overview of the COMPASS results ^*

Overview of the COMPASS results ^*

Estimation of wall forces solely from magnetic measurements: an application to RFX-mod experiment

Models for calculation of the sideways force due to the kink modes in tokamaks

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Sideways forces on asymmetric tokamak walls during plasma disruptions

Cited by 6 publications

References 49 publications

Overview of the COMPASS results *

Overview of the COMPASS results *

Estimation of wall forces solely from magnetic measurements: an application to RFX-mod experiment

Models for calculation of the sideways force due to the kink modes in tokamaks

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Overview of the COMPASS results ^*

Overview of the COMPASS results ^*