UKAEA Papers

"Electric field ionization probabilities for the hydrogen atom"

• DS Bailey
• JR Hiskes
• AC Riviere

"Threshold electric field for dissociation of the H2 ion"

• H Wind

"Diffusion of trapped reversed magnetic field in a theta pinch in the presence of a probe"

• M Keilhacker

"Microwave propagation in a plasma with a sheared magnetic field"

• MA Heald

"Modelling the effects of misaligning the probe beam and magnetic field in Doppler backscattering measurements"

• V.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…

"Experimental and modelling study of locked mode dynamics prior to disruptions in high performance JET plasmas"

• L. Piron
• T. C. Hender
• E. Joffrin
• F. Auriemma
• P. Buratti
• R. Paccagnella
• P. Zanca
• C. Challis
• S. Gerasimov
• R. B. Henriques
• L. Marrelli
• P. Lomas
• F. Rimini
• D. Terranova

The presence of Error Fields (EFs) in magnetic fusion devices can affect energy confinement and plasma stability by braking plasma rotation, by inducing fast particle losses and being amplified when exploring high-b regimes. The resulting EF Locked Modes (LMs) can be stabilized by NBI injection through the rotation shielding mechanism. However, …

"The Impact of Symmetry Breaking on Pedestal Stability of Tokamak Plasmas"

• M.S. Anastopoulos-Tzanis
• C.H. Ham
• H.R. Wilson

H-mode tokamak plasmas are typically characterised by quasi-periodic instabilities called edge localised modes (ELMs) driven by unstable peeling-ballooning modes [1]. For large scale fusion power plants, the predicted particle and heat fluxes are unacceptable, and an active ELM control method is required. One promising method relies on t…

"DEMO First Wall misalignment study by 3D field line tracing"

• Maria Lorena Richiusa
• Wayne Arter
• Dominic Calleja
• Medhi Firdaouss
• Jonathan Gerardin
• Michael Kovari
• Francesco Maviglia
• Zsolt Vizvary

Within the framework of EUROfusion DEMO First Wall and limiter design activities, the protection of the First Wall against power deposition peaks is being considered. During steady-state operation, the radiative power from the plasma could be considered uniformly spread on plasma-facing components. However, the presence of openings (i.e. g…

"Toroidal modelling of core plasma flow damping by RMP fields in hybrid discharge on ASDEX Upgrade"

• N. Zhang
• Y. Q. Liu
• P. Piovesan
• V. Igochine
• D. L. Yu
• S. Wang
• G. Q. Dong
• G. Z. Hao
• G. L. Xia
• W. J. Chen
• L. Liu
• J. Q. Li
• X. Bai

Resistive plasma response to the n = 1 (n is the toroidal mode number) RMP field is systematically investigated for a high-beta hybrid discharge on ASDEX Upgrade. Both linear and quasi-linear response are modelled using the MARS-F and MARS-Q codes, respectively. Linear response computations show a large internal kink response when the plasma centra…

"System Studies of Spherical Tokamaks"

• Stuart I. Muldrew
• Hanni Lux
• Tim C. Hender
• Bhavin Patel
• Peter J. Knight
• Garry M. Voss
• Howard R. Wilson

Spherical Tokamaks offer a number of potential advantages for a future fusion power plant. They have a high ratio of thermal to magnetic field pressure (beta) and strong flows, either of which could result in reduced turbulence. Fewer Toroidal Field (TF) coils and a different geometry offers the potential for new methods of remote maintenance …