R O Dendy B Chapman B C G Reman J W S Cook
Observations of radiation in the ion cyclotron range of frequencies from the KSTAR tokamak and LHD heliotron-stellarator show that energetic neutral beam injected (NBI) ion populations can relax collectively in the edge plasma near the injection point. The resulting radiation is ion cyclotron emission (ICE), whose spectrum has strongly suprather…
PreprintM. Marin J. Citrin L. Garzotti M. Valovic C. Bourdelle Y. Camenen F. J. Casson A. Ho F. Koechl M. Maslov JET contributors
The pellet cycle of a mixed isotope tokamak plasma is successfully reproduced with reduced turbulent transport modelling within an integrated simulation framework. In JET tokamak experiments, deuterium pellets with reactor-relevant deposition characteristics were injected into a pure hydrogen plasma. Measurements of the isotope ratio profile inf…
PreprintB Chapman R O Dendy S C Chapman K G McClements R Ochoukov
Observations have recently been made of ion cyclotron emission (ICE) that originates from the core plasma in the DIII-D and ASDEX-Upgrade tokamaks. In some of these cases, the ICE spectral peaks correspond to the local cyclotron harmonic frequencies of fusion-born ions close to the magnetic axis. This is in contrast to the hitherto usual spatial lo…
PreprintW.W. Heidbrink A. Garcia W. Boeglin M. Salewski
The weight function W(X) is a diagnostic sensitivity to phase-space variables X that relates the measured signal C to the distribution function F(X) through the equation C = ∫ W(X)F(X)dX. In the present work, an algorithm to calculate W for a diagnostic that measures 3 MeV protons produced in d(d,p)t fusion reactions between a fast ion and a th…
Preprint PublishedM.S. Anastopoulos Tzanis C.J. Ham P.B. Snyder H.R. Wilson
The poloidal harmonics of the toroidal normal modes of an unstable axisymmetric tokamak plasma are employed as basis functions for the minimisation of the 3D energy functional. This approach presents a natural extension of the perturbative method considered in [M.S. Anastopoulos Tzanis et al, Nuclear Fusion 59:126028, 2019]. This variational formul…
Preprint PublishedS.Hall P.Jacquet G.Naylor
The Mega Amp Spherical Tokamak (MAST) is currently being extensively upgraded to provide a system that will be able to add to the knowledge base for ITER as well as testing innovative reactor systems such as the Super-X divertor. MAST-U will have increased coil system and power supply capability. Therefore, to ensure operation of MAST-U within safe…
Preprint PublishedG. M. Staebler J. Candy E. Belli J. E. Kinsey N. Bonanomi B. Patel
The findings of an investigation into the properties of the three dimensional (3D) saturated fluctuation intensity of the electric potential in gyrokinetic turbulence simulations is presented. Scans in flux surface elongation and Shafranov shift are used to isolate the tokamak geometric dependencies. The potential intensity required in order to …
Preprint PublishedD. Moulton P. C. Stangeby X. Bonnin R. A. Pitts
If correct, the Lengyel model offers a simple and powerful tool to predict the conditions required for detachment onset in future fusion reactors. We assess its validity against a comprehensive SOLPS-4.3 simulation database of ITER baseline (Q = 10) neon-seeded plasmas (Pacher et al 2015 J. Nucl. Mater. 463 591). In absolute terms, the Lengyel Mode…
Preprint PublishedThomas R. Barrett T. Grant M. Kovari N. Mantel A. Muir
Investment in past fusion experiments has been motivated largely by the study of tokamak physics, and has been vital to provide a sound physics basis for design of a power reactor. However, meeting the challenge of realising fusion energy production will require considerable and increasing investment in facilities for testing and development of fus…
Preprint Published