Toroidal Flow Research Articles

Modeling of thermal-ion-driven internal kink in DIII-D high-T i plasmas

Toroidal modeling utilizing the non-perturbative magnetohydrodynamic-kinetic hybrid code MARS-K (Liu Y.Q. et al 2008 Phys. Plasmas 15 112503), to a DIII-D high-performance discharge with the core thermal ion temperature of T i ∼ 13 keV, finds multiple branches of unstable internal kink (IK) modes triggered by the bounce resonance of trapped thermal ions. The range of the computed mode frequency aligns well with the bounce frequency of trapped thermal ions, confirming the nature of resonance drive for the instability. The computed mode frequency is close to that observed in experiments. Plasma toroidal flow, in particular the fast flow (10% of Alfvén speed) as in the considered DIII-D discharge, strongly stabilizes the fluid IK branch but not all of the thermal-ion-driven internal kink (TIK) branches, leaving one dominant unstable TIK branch under the experimental conditions. Plasma resistivity also significantly affects stability of the TIKs (but not much on the IK which is ideally strongly unstable) in combination with the drift kinetic drive by thermal ions. High resistivity can drive additional unstable TIK branches. Scanning the on-axis safety factor over a large range confirms robustness of the TIK triggering by thermal ions. The computed TIKs contain both the IK and the tearing components as the dominant contributions to the eigenmode structure. These findings, together with the experimental results reported in reference (Du X.D. et al 2021 Phys. Rev. Lett. 127 025001), strongly suggest the possibility of thermal-ion driven instabilities in ITER.

A possible mechanism for spontaneous cyclic back-arc spreading

Back-arc spreading is a non-steady-state process exemplified by the repeated cycles of spreading of the South Fiji and the Lau Basins behind the Tonga arc, and the Parece Vela Basin and the Mariana Trough behind the Mariana arc. Spreading in these regions starts with rifting within the volcanic arc before shifting to the back-arc region where it develops into a phase of well-defined spreading. 2D thermo-mechanical subduction modeling incorporating phase transitions at depths of 410 km and 660 km suggests the presence of a low-viscosity and low-density mantle wedge is an important condition for arc rifting to occur. Back-arc spreading starts when a nearly vertical slab impinges upon the 660 km discontinuity causing downdip compressive stress that is transmitted up the slab resulting in extensional within-arc stress. Trench retreat during a phase of back-arc spreading causes a decrease in slab dip angle and buckling of the slab. Back-arc spreading ceases during this buckling phase. Rifting starts once more when the nearly vertically dipping ‘heel’ of the buckled slab again impinges upon the 660-km boundary. The second phase of rifting initially focuses within the arc but subsequently shifts to the back-arc region leading to renewed back-arc spreading. Our modeling predicts that subduction of thick (old age) and weak (small yield stress) slabs, which have intermediate resistance to slab bending, leads to cyclic back-arc spreading. In contrast, continuous back-arc spreading is predicted for thick and strong slabs with a large resistance to bending, and no back-arc spreading is predicted for slabs with a small resistance to bending (thin slabs). Geological processes such as toroidal mantle flow around the lateral edges of a slab, collisions with buoyant lithosphere and interactions with third plates may have important roles in the development of cyclic back-arc spreading in specific cases. However, the presence of a common timescale of ~ 20 Myr suggests there a general underlying control on back-arc basin formation that is common to many if not all subduction zones. The new model presented here can account for the main features of cyclic back-arc spreading seen in the Tonga-Kermadec and the Calabrian arcs.

Application of The Classical Soliton Theory to Study the Dynamics in PassiveDispersed and Active-Relaxation Media During the Formation of a Twist in A Toroidal Plasma

In this paper we consider the possibility of using analog models to study the behavior of the evolution and dynamics of toroidal vortex flows. The current model based on coupled van der Pol generators is used as the main one. In this robot, based on nonlinear dynamics display Bernoulli presented the evolution of the Torus. The use of analog models makes it possible to trace the dynamics of vortex flows. In General, the presented results allow us to confidently assert that both in the experiment and in the theoretical consideration we are dealing with the same object - a strange attractor of the Smale – Williams type in a non-Autonomous oscillatory system. The available data suggest that it is an attractor of hyperbolic type, although, strictly speaking, this statement needs mathematical proof. The appearance of an example of a physical system with a hyperbolic chaotic attractor is of fundamental importance for the further development of nonlinear dynamics and its applications. This is, in a sense, a "breakthrough into the hyperbolic realm." Based on the inherent property of coarseness of hyperbolic attractors, we can build other examples of systems with hyperbolic chaos. The presence of such physical systems opens up opportunities for the application of a deeply studied branch of mathematics – hyperbolic theory, and also translates into practice the problem of comparative study of hyperbolic and non-hyperbolic chaos in theory and experiment. This system can be used to study toroidal vortex processes.

Liquid dripping dynamics and levitation stability control of molten Ti–Al–Nb alloy within electromagnetic fields

The dripping dynamics of the electromagnetically levitated (EML) liquid Ti–Al–Nb alloy under high temperatures was investigated by both numerical simulation based on the Arbitrary Lagrangian–Eulerian method and corresponding EML experiments. A dripping formation parameter εD was defined to describe the critical shape of alloy droplet. According to the simulated results, the high-temperature dripping phenomenon took place when εD < 0.68, which was in good agreement with experimental data. When dripping event occurred, the Lorentz force applied on alloy droplet decreased by approximately 11.7% within 0.07 s. Three typical methods were accordingly proposed to avoid the dripping failure of a bulk liquid Ti–Al–Nb alloy, which was implemented by enhancing electric current, adjusting levitation coil diameter, or increasing coil winding number. To control the droplet shape, the deformation pattern and the flow behavior of the liquid alloy were studied in a wide current range from 700 to 1400 A. With the increase in excitation current, the cone-shaped alloy melt transformed to a rhombus, and the flow behavior transformed from a typical four toroidal flow vortexes up to a complex eight toroidal flow vortexes. Moreover, the centroid position of liquid alloy rose up significantly at first and then slowly approached to levitation ceiling.

Complex Patterns of Mantle Flow in Eastern SE Asian Subduction Zones Inferred From P‐Wave Anisotropic Tomography

AbstractWe determine 3‐D isotropic and anisotropic P‐wave velocity models beneath eastern SE Asia by inverting a large number of P‐wave arrival times selected from the ISC‐EHB database. Our results reveal detailed structures of the subducting South China Sea (SCS), Negros, Molucca Sea, Philippine Sea, and Banda slabs, the previously subducted Proto‐SCS slab and remnants of other paleo slabs, showing long‐lived subductions of these oceanic slabs in eastern SE Asia. There is an obvious change in the subduction angle of the SCS slab at 18°N along the Manila trench. We suggest that the relatively low dip angle of the SCS slab to the south of 18°N was caused by subduction of an extinct mid‐ocean ridge, and a slab tear is possibly formed at 18°N. This feature is supported by the resolved fast velocity directions (FVDs) of P‐wave azimuthal anisotropy in the mantle wedge, which show that 3‐D toroidal mantle flow may develop around the southern part of the SCS slab. Trench‐normal FVDs are revealed in the deeper mantle wedge of the Sangihe subduction zone, which are associated with the deep subduction and stagnancy of the Molucca Sea slab. A nearly trench‐parallel FVD is observed beneath the Molucca Sea slab, which may be caused by trench‐parallel extension due to the retreating slab or reflect subslab mantle flow associated with the double‐sided subduction. The subducting Banda slab exhibits a curved feature, which greatly affects the flow pattern in the mantle wedge.

Application of The Classical Soliton Theory to Study the Dynamics in PassiveDispersed and Active-Relaxation Media During the Formation of a Twist in A Toroidal Plasma

In this paper we consider the possibility of using analog models to study the behavior of the evolution and dynamics of toroidal vortex flows. The current model based on coupled van der Pol generators is used as the main one. In this robot, based on nonlinear dynamics display Bernoulli presented the evolution of the Torus. The use of analog models makes it possible to trace the dynamics of vortex flows. In General, the presented results allow us to confidently assert that both in the experiment and in the theoretical consideration we are dealing with the same object - a strange attractor of the Smale – Williams type in a non-Autonomous oscillatory system. The available data suggest that it is an attractor of hyperbolic type, although, strictly speaking, this statement needs mathematical proof. The appearance of an example of a physical system with a hyperbolic chaotic attractor is of fundamental importance for the further development of nonlinear dynamics and its applications. This is, in a sense, a "breakthrough into the hyperbolic realm." Based on the inherent property of coarseness of hyperbolic attractors, we can build other examples of systems with hyperbolic chaos. The presence of such physical systems opens up opportunities for the application of a deeply studied branch of mathematics – hyperbolic theory, and also translates into practice the problem of comparative study of hyperbolic and non-hyperbolic chaos in theory and experiment. This system can be used to study toroidal vortex processes.

In-out charge exchange measurements and 3D modelling of diagnostic thermal neutrals to study edge poloidal impurity asymmetries

A new method was developed to model the neutral population produced by the gas puff based charge exchange recombination spectroscopy systems at ASDEX Upgrade (AUG). With this method, the edge impurity density on the high field side (HFS) and low field side (LFS) can be obtained without the need to apply a neutral beam injection system. The neutral penetration needed for the calculation of the impurity density is obtained with a new gas puff module implemented in the FIDASIM code. The LFS impurity density profile evaluated with the new gas puff module matches the impurity density calculated with standard beam-based charge exchange diagnostics. Impurity temperature, rotation and density profiles at the HFS and LFS of an AUG H-mode discharge are presented. Edge impurity toroidal and poloidal flows show asymmetric structures. The impurity density asymmetries obtained with the new gas puff module are consistent with the observed flow structure.

Free-boundary plasma equilibria with toroidal plasma flows

Magnetohydrodynamic equilibrium schemes with toroidal plasma flows and scrape-off layer are developed for the ‘divertor-type’ and ‘limiter-type’ free boundaries in the tokamak cylindrical coordinate. With a toroidal plasma flow, the flux functions are considerably different under the isentropic and isothermal assumptions. The effects of the toroidal flow on the magnetic axis shift are investigated. In a high beta plasma, the magnetic shifts due to the toroidal flow are almost the same for both the isentropic and isothermal cases and are about 0.04a 0 (a 0 is the minor radius) for M 0 = 0.2 (the toroidal Alfvén Mach number on the magnetic axis). In addition, the X-point is slightly shifted upward by 0.0125a 0. But the magnetic axis and the X-point shift due to the toroidal flow may be neglected because M 0 is usually less than 0.05 in a real tokamak. The effects of the toroidal flow on the plasma parameters are also investigated. The high toroidal flow shifts the plasma outward due to the centrifugal effect. Temperature profiles are noticeable different because the plasma temperature is a flux function in the isothermal case.

Charge exchange spectroscopy using spatial heterodyne spectrometer in the large helical device.

In this study, the use of a spatial heterodyne spectrometer (SHS) to measure the toroidal flow velocity (Vf) and the ion temperature (TC6+ ) of the C6+ impurity ion by charge exchange spectroscopy was explored. The instrumental width (IW) of the SHS (aperture size = 16.77 mm2, etendue = 2.9867 mm2sr) was extrapolated to be 0.09nm, which is half of the 0.17nm IW extrapolated for a conventionally used dispersive spectrometer (DS) (aperture size = 2.6 mm2, etendue = 0.2605 mm2sr). The resulting Vf and TC6+ measurements were found to be in good agreement with those measured using the DS.

Ferrofluidic Couette flow in time-varying magnetic field

Despite time-dependent boundary conditions being ubiquitous in natural and industrial flows, to date the influence of such temporal modulations (e.g. with driving frequency ΩH) has been given minor attention. The present problem addresses ferrofluidic Couette flow in between counter-rotating cylinders in a spatially homogeneous magnetic field subject to time-periodic modulation. Such a modulation can lead to a significant inner Reynolds number (Rei) enhancement for both, either helical and toroidal flow structures. Using a modified Niklas approximation, the effect of low- and high-frequency modulation onto the primary instabilities, stability boundaries as well as on the non-linear oscillations that may occur is investigated. Focusing on bi-stable co-existing solutions, around their stability thresholds quite complex non-linear system response and flow dynamics is detected. For the system remaining supercritical always a single solution is selected by ΩH, while crossing the bifurcation thresholds within a modulation period the triggered system response is more complex, reaching from alternation between different solutions towards the appearance of intermittent behavior.

Nonaxisymmetry and flow transition in evaporating water drops

Understanding the internal flow in evaporating sessile drops is of paramount importance in a myriad of applications such as ink-jet printing, surface patterning, and medical diagnostics. Marangoni flow driven by a gradient in surface tension is an essential internal flow mechanism, whose characteristics in evaporating water drops remain elusive in the literature. Here, by employing infrared thermography and particle image velocimetry, we show that the manifestation of Marangoni flow as a convective cell at the liquid–vapor interface results in a nonaxisymmetric internal flow field. Eventually, during evaporation, the flow transitions to a buoyancy-dominated regime, where an axisymmetric toroidal flow is observed. This transition marks a reversal in the flow along with an order of magnitude decrease in velocity. We corroborate this experimentally observed transition using previously reported analytical and scaling frameworks. Finally, we present hitherto unreported features correlating the three aspects of evaporating water drops, viz., contact line dynamics, thermal field, and internal flow field, which are generally investigated independently.

Movement speed of the directional crystallization front of aluminum in a cylindrical crucible under different MHD-stirring modes

To improve the quality of continuous cylindrical ingots of aluminum and its alloys produced in continuous casting machines, MHD-stirring is implemented in the hot top of the mold. For this purpose, poloidal and toroidal flows are excited in the molten metal. These flows significantly affect heat the transfer from the hot metal entering the hot top of the mold to the cooling zone, where thecrystallization front is formed. The experiment showed that the toroidal flow first reduces the speed of the advance of the crystallization front, and then, as the rotating field magnitude increases, the speed ceases to change noticeably. The poloidal flow also first reduces the crystallization front speed, but somewhat faster than the toroidal flow, and there is a minimum on the curve of the dependence of the front advance speed on the traveling field magnitude, after which the crystallization front speed begins to increase. It has been found that under the combined action of travelling and rotating magnetic fields, the speed of advance of the crystallization front first decreases, and then increases.

Influence of toroidal rotation on plasma response to external RMP fields in tokamak

The type-I edge localized mode (ELM) is a critical event associated with magneto-hydrodynamic(MHD) instabilities occurring in tokamak high-confinement (H-mode) discharges, that leads to huge heat loads on the plasma phasing components (PFC) and may result in material damages. It is important to effectively control large ELMs, in order to ensure safe operation of the future reactor-scale devices such as ITER and DEMO. Resonant magnetic perturbation (RMP) has been experimentally demonstrated to be a mature and robust technique for controlling ELMs. A set of parameters, such as the edge safety factor, the plasma flow, the RMP coil geometry and the spectrum of the applied external field, have been found to play important roles in controlling ELMs by RMP. Furthermore, the plasma pressure is known to affect the plasma response to the RMP field, in particular near the no-wall beta limit. This is because high plasma pressure drives the resonant field amplification of the external field by the plasma response. The ITER 10 MA steady state scenario will be operated near the no-wall stability limit. The new tokamak device HL-2M will also operate in the relatively high-beta regimes. On the other hand, more investigations are still needed to understand the influence of toroidal flow on the high-beta plasma response. This work employs a single fluid toroidal model to compute the plasma RMP response in HL-2M, emphasizing on the roles of two key physical quantities: the plasma resistivity and the toroidal rotation. The former allows penetration of the external RMP field into the plasma, while the latter mainly provides screening effect on the resonant field component. More specifically, the MARS-F code is utilized to study the plasma response to the externally applied <i>n</i> =1 ( n is the toroidal mode number) RMP field for high-beta HL-2M discharges, while varying the plasma toroidal rotation profile. The plasma response is found to (i) substantially modify the poloidal spectrum of the applied vacuum RMP field, (ii) change the amplitude of the resonant radial field amplitude near the plasma edge, and (iii) affect optimal current phasing between the two rows of RMP coils on HL-2M. A sufficiently slow toroidal flow near the plasma edge amplifies the radial field at rational surfaces associated with the perturbation. Since the latter serves as a reliable indicator for controlling the type-I edge localized mode (Type-I ELM) by RMP, varying rotation profile near the plasma edge offers a promising approach to optimize ELM control.

Influence of Hall effect and toroidal flow on the plasmoid formation and incomplete reconnection in a low resistivity plasma in tokamak

The nonlinear resistive-kink mode in the low resistivity plasma in tokamak is investigated through the three-dimensional, toroidal, and nonlinear Hall-MHD code CLT. It is found that, without the two-fluid effect and the toroidal flow, the system can evolve into a steady-state with the saturated main m/n = 1/1 magnetic island and the co-existing large secondary island. The main m/n = 1/1 magnetic island cannot push the hot core plasma out of the q = 1 surface as it does in Kadomstev’s model, and the reconnection is incomplete. However, with the two-fluid effect or the toroidal flow, the nonlinear behaviors of the resistive-kink mode could be essentially different. The two-fluid effect and the toroidal flow can break the symmetry during the plasmoid formation, which destroys the balance between the main m/n = 1/1 magnetic island and the large secondary island. The large secondary island is then merged into the main m/n = 1/1 island. After that, the main m/n = 1/1 island finally occupies the whole mix region, and all magnetic flux in the mix region is reconnected. A similar simulation study has been done in periodic cylindrical geometry (Günter et al 2015 Plasma Phys. Control. Fusion 57 014017), while our work is done in tokamak toroidal geometry. The toroidal effect has also been investigated, and we find that the widths of the main 1/1 island and the secondary island slightly increase with increasing aspect ratios.

Mapping the Pacific Slab Edge and Toroidal Mantle Flow Beneath Kamchatka

AbstractTo clarify the upper mantle structure and dynamics of the Kamchatka subduction zone, we conduct Rayleigh‐wave phase‐velocity azimuthal anisotropy tomography beneath Kamchatka using amplitude and phase data of teleseismic fundamental mode Rayleigh‐waves at periods of 25–150 s. With the obtained anisotropic phase‐velocity model, a 3‐D azimuthal anisotropic shear‐wave velocity (Vs) model is determined down to ∼300 km depth. Beneath Kamchatka, the subducting Pacific slab is clearly imaged as a dipping high‐Vs zone on the south of the Shiveluch volcano at ∼57°N latitude, whereas this high‐Vs zone is absent on the north of the volcano, suggesting that a slab edge exists in the region. Visible low‐Vs anomalies are revealed around the slab edge. The subducting Pacific slab beneath Kamchatka generally exhibits a fast‐velocity direction (FVD) of ∼NE‐SW in the area south of ∼54°N latitude, whereas the dominant FVD in the slab rotates to ∼N‐S or ∼NNW‐SSE in the area of ∼54°–57°N latitude. The FVDs in the subducting Pacific slab are generally parallel to the Kamchatka trench, which may result from the shape‐preferred orientation of stratified oceanic lithosphere. At shallow depths (<∼150 km), the low‐Vs mantle wedge generally exhibits ∼ NW‐SE FVDs, whereas ∼ E‐W FVDs appear on the north of the slab edge, which form semi‐toroidal FVDs around the slab edge. The semi‐toroidal FVDs may reflect a combination of corner flow in the mantle wedge and toroidal mantle flow around the slab edge beneath Kamchatka, which may deform and heat or even melt the slab near its edge.

Structure of the JET edge radial electric field in He and D plasmas

Perpendicular velocity, v ⊥, measurements have been obtained in JET experiments designed to investigate the underlying mechanisms influencing the L–H power threshold. L–H transitions were induced by using both NBI and ICRH in deuterium and helium plasmas. The v ⊥ profile in the low density branch of the L–H transition has a modest or even no well and a marked peak near the separatrix in NBI heated discharges for both D and He plasmas, with a sharper SOL peak for He plasmas. As the line-averaged density increases, the SOL v ⊥ peak decreases, in agreement with the modifications in the electron temperature profile at the divertor target, while the v ⊥ well becomes deeper. Nevertheless, even in the high density branch, a shallow v ⊥ well is found at the L–H transition, v ⊥ ∼ 1–2 km s−1, which is lower by a factor of about two than the contribution from the diamagnetic term. No evidence for the existence of a critical value in v ⊥ is found at JET, particularly for helium plasmas. This may be explained by the existence of an edge toroidal flow relevant mainly at low density where the power threshold is high. In addition, no significant change in the edge v ⊥ is measured preceding the L–H transition.

Effects of electron cyclotron heating on the toroidal flow in LHD plasmas

The toroidal force related to electron cyclotron heating (ECH) is investigated in large helical device (LHD) plasmas. When we apply the ECH to the plasma kept by neutral beam injection (NBI) heating, the radial profile of the toroidal flow velocity changes drastically in LHD. ECH-generated supra-thermal electrons can apply forces on the plasma through radial electron current and collisions. We investigate the perturbed electron distribution due to ECH by using the GNET code, which can solve the 5D drift kinetic equation. We also evaluate the electromagnetic force due to radial current and the collisional force driven by ECH. As a result, we find a comparable force driven by ECH to that by NBI heating. The direction of the force is the counter (co) direction radially inside (outside) from the ECH heating location, and these directions correspond with that of experiment results. Finally, we evaluate toroidal flows in ECH and NBI heated plasma solving the radial diffusion equation and compare them with that of experimental observations. We reproduce the co-rotating toroidal flow quantitatively in the balanced-NBI+ECH heated case, but we see a difference in the toroidal flow profiles in the co-NBI+ECH heated case.

Investigating Toroidal Flows in the Sun Using Normal-mode Coupling

Abstract Helioseismic observations have provided valuable data sets with which to pursue the detailed investigation of solar interior dynamics. Among various methods to analyze these data, normal-mode coupling has proven to be a powerful tool, used to study Rossby waves, differential rotation, meridional circulation, and nonaxisymmetric multiscale subsurface flows. Here, we invert mode-coupling measurements from the Helioseismic Magnetic Imager and the Michelson Doppler Imager to obtain mass-conserving toroidal convective flow as a function of depth, spatial wavenumber, and temporal frequency. To ensure that the estimates of velocity magnitudes are proper, we also evaluate correlated realization noise, caused by the limited visibility of the Sun. We benchmark the near-surface inversions against results from local correlation tracking. The convective power likely assumes greater latitudinal isotropy with a decrease in spatial scale of the flow. We note the absence of a peak in toroidal-flow power at supergranular scales, in line with observations that show that supergranulation is dominantly poloidal in nature.

Can sub-slab low-velocity anomalies be an artifact caused by anisotropy? A case study from the Alboran slab area in the western Mediterranean

Although it is well understood that mantle flow in a subduction setting can develop seismic anisotropy, many tomographic studies still assume an isotropic mantle. In this study, we explore how unaccounted-for seismic anisotropy contributes to P-wave anomalies, focusing on apparent sub-slab low velocities. We use data from the westernmost Mediterranean, where the Alboran slab has subducted beneath the Gibraltar Arc. Our isotropic P-wave velocity model shows a low-velocity anomaly at depths of 75–225 km to the west of the high-velocity-anomaly that represents the Alboran slab. We explore whether this low-velocity anomaly could be an anisotropy-induced artifact as a significant shear-wave-splitting (SWS) along the arc is observed. We consider five different hypothetical anisotropy models representing different mantle configurations. The anisotropy models are based on 1) the SWS observations, 2) the depth distribution of the low-velocity anomaly and 3) geodynamic modeling of the development of entrained and toroidal mantle flow in generic subduction zones. Given the underdetermined nature of an anisotropic inversion, we include the anisotropy models as a priori constraints on the tomography. The tomographic results including anisotropy models have smaller travel time residuals and isotropic anomalies in the region of interest while fitting the SWS observation better than the isotropic model. We propose that unaccounted-for seismic anisotropy can produce artifacts in isotropic tomography of real datasets, and this is at least partially the case for the low-velocity anomaly below the Alboran slab. Further, we show that not taking this into account can lead to erroneous conclusions about mantle temperature and the presence of melt. From the insights that our anisotropy models provide, we also suggest that toroidal mantle flow is currently dominant below and around the Alboran slab.

Resistive wall mode stability and resonant field amplification in MAST high beta plasma

The n = 1 (n is the toroidal mode number) resistive wall mode (RWM) instability and the resonant field amplification (RFA) due to a stable RWM response are numerically investigated for an MAST high-pressure plasma scenario, utilizing the MARS-F Liu et al (2000 Phys. Plasmas 7 3681) and MARS-K Liu et al (2008 Phys. Plasmas 15 112503) codes, for the purpose of understanding the potential RWM behavior in MAST-U plasmas. Ideal kink stability analysis identifies a target plasma, with parameters similar to that of the reference equilibrium reconstructed from an MAST high-pressure discharge, that accesses the RWM regime. The unstable n = 1 RWM for the target equilibrium is subject to strong damping by the plasma toroidal flow and/or the drift kinetic effects from thermal particles. As a result, the mode is found to be stable under the experimental flow conditions, or even without flow stabilization if drift kinetic stabilization is included. The stability prediction is robust against variation of the assumed resistive wall minor radius. Active magneto-hydrodynamic (MHD) spectroscopy modeling, using the magnetic coils designed for controlling the edge localized modes (ELMs) in MAST-U as the antenna, shows strong RFA due to a stable RWM response in the target plasma. Maximal amplification, of 6–7 times larger than the applied vacuum field within the plasma, is obtained assuming a coil phasing of 120–180 degrees between the upper and lower rows of the ELM control coils. The MHD-kinetic hybrid model predicts generally higher RFA than the fluid model, in particular near the low-field and high-field sides of the plasma boundary surface. The MARS-F/K modeling thus shows that the RWM in MAST-U is subject to strong flow and kinetic stabilization, but can nevertheless be detected by active MHD spectroscopy.