In-vessel, non-axisymmetric, control coils have proven to be an important option for mitigating and suppressing edgelocalized modes (ELMs) in high performance operating regimes on a growing number of tokamaks. Additionally, an in-vessel non-axisymmetric ELM control coil is being considered in the ITER baseline design. In preparing for the initial operation of this coil set, a comprehensive study was carried out to characterize the linear superposition of the 3D vacuum magnetic field, produced by the ELM coil, on a series of equilibria representing nine standard ITER operating scenarios. Here, the spatial phase angle of toroidally distributed currents, specified with a cosine waveform, in the upper and lower rows of the ITER ELM coil (IEC) set is varied in 2 • steps while holding the current in the equatorial row of coils constant. The peak current in each of the three toroidal rows of window-frame coils making up the IEC is scanned between 5 kAt and 90 kAt in 5 kAt steps and the width of the edge region covered by overlapping vacuum field magnetic islands is calculated. This width is compared to a vacuum field ELM suppression correlation criterion found in DIII-D. A minimum coil current satisfying the DIII-D criterion, along with an associated set of phase angles, is identified for each ITER operating scenario. These currents range from 20 kAt to 75 kAt depending on the operating scenario being used and the toroidal mode number (n) of the cosine waveform. Comparisons between the scaling of the divertor footprint area in cases with n = 3 perturbation fields versus those with n = 4 show significant advantages when using n = 3. In addition, it is found that the DIII-D correlation criterion can be satisfied in the event that various combinations of individual IEC window-frame coils need to be turned off due to malfunctioning components located inside the vacuum vessel. Details of these results for both the full set of 27 window-frame coils and various reduced sets, using either n = 3 and n = 4 perturbation fields, are discussed.

Impurities (H2, D2, He, Ne or Ar) injected into steady (non-disrupting) discharges with massive gas injection (MGI) are shown to mix into the plasma core dominantly via magnetohydrodynamic activity during the plasma thermal quench (TQ). Mixing efficiencies of injected impurities into the plasma core are measured to be of order 0.05–0.4. 0D modelling of the experiments is found to reproduce observed TQ and current quench durations reasonably well (typically within ±25% or so), although shutdown onset times are underestimated (by around 2×). Preliminary 0D modelling of ITER based on DIII-D mixing efficiencies suggests that MGI will work well in ITER with regard to disruption heat load and vessel force mitigation, but may not collisionally suppress runaway electrons.

Experiments have been performed in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] toward understanding runaway electron formation and amplification during rapid discharge shutdown, as well as toward achieving complete collisional suppression of these runaway electrons via massive delivery of impurities. Runaway acceleration and amplification appear to be well explained using the zero-dimensional (0D) current quench toroidal electric field. 0D or even one-dimensional modeling using a Dreicer seed term, however, appears to be too small to explain the initial runaway seed formation. Up to 15% of the line-average electron density required for complete runaway suppression has been achieved in the middle of the current quench using optimized massive gas injection with multiple small gas valves firing simultaneously. The novel rapid shutdown techniques of massive shattered pellet injection and shell pellet injection have been demonstrated for the first time. Experiments using external magnetic perturbations to deconfine runaways have shown promising preliminary results.

Polyaniline is intercalated into layered manganese oxide in situ, at an aqueous/ organic interface. The prepared polymer‐intercalated manganese oxide has several novel characteristics — a swelled layered structure, a uniform mesoporous structure, a typical nanosize, and a high surface area, resulting in a high electrochemical performance for Li storage.

The first results of edge-localized mode (ELM) pacing using small spherical lithium granules injected mechanically into H-mode discharges are reported. Triggering of ELMs was accomplished using a simple rotating impeller to inject sub-millimetre size granules at speeds of a few tens of meters per second into the outer midplane of the EAST fusion device. During the injection phase, ELMs were triggered with near 100% efficiency and the amplitude of the induced ELMs as measured by Dα was clearly reduced compared to contemporaneous naturally occurring ELMs. In addition, a wide range of granule penetration depths was observed. Moreover, a substantial fraction of the injected granules appeared to penetrate up to 50% deeper than the 3 cm nominal EAST H-mode pedestal width. The observed granule penetration was, however, less deep than suggested by ablation modelling carried out after the experiment. The observation that ELMs can be triggered using the injection of something other than frozen hydrogenic pellets allows for the contemplation of lithium or beryllium-based ELM pace-making on future fusion devices. This change in triggering paradigm would allow for the decoupling of the ELM-triggering process from the plasma-fuelling process which is currently a limitation on the performance of hydrogen-based ELM mitigation by injected pellets.