N J Conway A Cackett C F Maggi A G Meigs K-D Zastrow T M Biewer D L Hillis
Since 2010, an in-vessel calibration light source (ICLS) has been used periodically on JET to calibrate a range of diagnostics at UV, visible and IR wavelengths. During shutdowns, the ICLS (essentially an integrating sphere) is positioned within the vacuum vessel by the remote handling (RH) system. Following the 2013 run, several changes were made …
Preprint PublishedJ. Simpson D. Moulton C. Giroud D. Harting G. Corrigan M. Groth JET Contributors
EDGE2D-EIRENE simulations of upstream density and radiative power scans in JET H-mode type plasmas in vertical target predict a linear relationship between the electron and ion temperatures, and power across the separatrix. This is in contradiction to the two-point model equations which states that the upstream temperature scales at the po…
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 PublishedR. Kembleton W. Morris G. Federicia A. J. H. Donné
The EUROfusion Roadmap for fusion research was recently updated and describes a clear set of missions and associated goals on the route to commercial fusion electricity. Beyond ITER, the main target of the programme is the development of DEMO, a fusion technology demonstrator which will produce substantial net electrical output, breed its own fu…
Preprint PublishedIan Chapman Nick Walkden
Fusion energy is an area of active development and innovation worldwide, with many design concepts exhibiting a range of technical challenges. A significant portion of technical challenges will be unique for a given design concept, however there are several overarching challenges that any design must address to some degree. These include: Tritiu…
Preprint PublishedStuart I. Muldrew Felix Warmer Jorrit Lion Hanni Lux
With a lack of plasma disruptions and current-driven instabilities, stellarators are potentially an attractive option for a fusion power plant. Previous system studies have been performed to optimise a HELIAS (HELIcal-axis Advanced Stellarator) 5-B power plant using PROCESS, however these have been based around a single design point. In reality …
Preprint PublishedA. R. Jackson A. S. Jacobsen K. G. McClements C. A. Michael M. Cecconello
The efficient confinement of fast ions is crucial to the development of a fusion power plant. Sawtooth crashes are a manifestation of an internal kink instability, which can severely degrade this confinement. The effect of these on a fast ion population can be investigated using fast-ion deuterium-alpha (FIDA) spectroscopy, where charge exchange…
Preprint PublishedR.A. Tinguely P.G. Puglia N. Fil S. Dowson M. Porkolab A. Fasoli D. Testa JET Contributors
This paper presents results of extensive analysis of mode excitation observed during the operation of the Alfvén Eigenmode Active Diagnostic (AEAD) in the JET tokamak during the 2019-2020 deuterium campaign. Six of eight toroidally-spaced antennas, each with independent power and phasing, were successful in actively exciting stable MHD modes in…
Preprint PublishedO. P. Bardsley T. C. Hender
Reduced activation ferritic steels are an attractive option for use in large structural components surrounding tokamak plasmas in future fusion power plants, but their ferromagnetic response to the confining magnetic fields must be properly understood. Simultaneously, the advantages of operating at high plasma elongation push tokamak designs tow…
Preprint PublishedA. De Backer C. Domain C.S. Becquart L. Luneville D. Simeone A. E. Sand K. Nordlund
The impacts of ions and neutrons in metals causes cascades of atomic collisions that expand and shrink, leaving microstructure defect debris, i.e. interstitial or vacancy clusters or loops of different sizes. In [A. De Backer, A. E. Sand, K. Nordlund, L. Lun´eville, D. Simeone, and S. L. Dudarev. EPL, 115(2):26001, 2016.], we described a method…
Preprint Published