M.S. Anastopoulos-Tzanis B.D. Dudson C.J. Ham C.C. Hegna P.B. Snyder H.R. Wilson
A linear perturbation theory is used to model the MHD stability of tokamak equilibria under the application of external 3D magnetic perturbations [C.C. Hegna, Physics of Plasmas 21 :072502, 2014]. The symmetry breaking produces the coupling of toroidal n modes. We use ELITE [H.R. Wilson et al., Physics of Plasmas 9 :1277, 2002] to produ…
Preprint PublishedJ F Parisi F I Parra C M Roach C Giroud W Dorland D R Hatch M Barnes J C Hillesheim N Aiba J R Ball P G Ivanov
Local linear gyrokinetic simulations show that electron temperature gradient (ETG) instabilities are the fastest growing modes for kyρi >~ 0.1 in the steep gradient region for a JET pedestal discharge (92174) where the electron temperature gradient is steeper than the ion temperature gradient. Here, ky is the wa…
Preprint PublishedP G Ivanov A A Schekochihin W Dorland A R Field F I Parra
The saturated state of turbulence driven by the ion-temperature-gradient instability is investigated using a two-dimensional long-wavelength fluid model that describes the perturbed electrostatic potential and perturbed ion temperature in a magnetic field with constant curvature (a Z-pinch) and an equilibrium temperature gradient. Numerical simulat…
Preprint PublishedD. B. King E. Viezzer I. Balboa M. Baruzzo E. Belonohy J. Buchanan I.S. Carvalho K. Cave-Ayland I. Coffey C.D. Challis E.G. Delabie L. Garzotti S. Hall J.Hillesheim L. Horvath E. Joffrin D. Keeling K. Kirov C.F. Maggi M. Maslov S. Saarelma S. Silburn E.R. Solano M. Stamp D. Valcarcel H.Weisen
A study of mixed hydrogen-deuterium H-mode plasmas has been carried out in JET-ILW to strengthen the physics basis for extrapolations to JET D-T operation and to support the development of strategies for isotope ratio control in future experiments. Variations of input power, gas fuelling and isotopic mixture were performed in H-mode plasmas of the…
Preprint PublishedM Valovič P T Lang A Kirk W Suttrop A Bock P J Mc Carthy M Faitsch B Plöckl2 the ASDEX Upgrade team the EUROfusion MST1 team
It is demonstrated that tokamak plasma can be fuelled by pellets while simultaneously maintaining ELM suppression by external resonant magnetic perturbations (RMPs). Pellets are injected from vertical high field site and deposited at outer part of plasma cross section. Each pellet triggers benign MHD event followed by short lived ELM free phase. Th…
Preprint PublishedM Marin J Citrin C Bourdelle Y Camenen F J Casson A Ho F Koechl M Maslov JET Contributors
Core turbulent particle transport with multiple isotopes can display observable differences in behaviour between the electron and ion particle channels. Experimental observations at JET with mixed H-D plasmas and varying NBI and gas-puff sources [M. Maslov et al., Nucl. Fusion 7 076022 (2018)] inferred source dominated electr…
Preprint PublishedD Darby-Lewis J Tennyson S N Yurchenko K D Lawson
Beryllium is being adopted for plasma facing walls in fusion reactors. This has led to the observation of emissions from the A 2Π state of beryllium hydride. Use of these emissions to monitor Be erosion requires electron impact excitation rates. Cross sections for electron-impact vibrational excitation within the X 2Σ + state and vibrationally…
Preprint PublishedC. Bowman J. R. Harrison B. Lipschultz S. Orchard K. J. Gibson M. Carr K. Verhaegh O. Myatra
Advancing our understanding of divertor plasma physics is limited by an inability to directly determine the plasma characteristics (density, temperature, etc) over the entire divertor cross-section. At best, diagnostics are able to measure ne and Te at isolated points. More commonly however, diagnostics only measure higher-level quantities (e.g. em…
Preprint PublishedV.H. Hall-Chen F.I. Parra J.C. Hillesheim
The use of Doppler Backscattering (DBS) in spherical tokamaks is challenging since the magnetic pitch angle can be large (up to 35, compared to 15 in standard tokamaks like JET). Moreover the pitch angle varies both spatially and temporally. Hence, the probe beam is generally not perpendicular to the magnetic field. This misalignment, which affec…
Preprint PublishedS.F. Smith S.J.P. Pamela A. Fil M. Hoelzl G.T.A. Huijsmans A. Kirk D. Moulton O. Myatra A.J. Thornton H.R. Wilson
ELM simulations for the MAST-U Super-X tokamak have been obtained, using the JOREK code. The JOREK visco-resistive MHD model has been used to obtain comparisons of divertor configurations. The simulations show a factor 10 decrease in the peak heat flux to the outer target of the Super-X in comparison to a conventional divertor configuration. A roll…
Preprint Published