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 …
Preprint PublishedA. Fil B. Dudson B. Lipschultz D. Moulton O. Myatra K. Verhaegh O. Fevrier J. Harrison A. Thornton M. Wensing
Plasma detachment needs to be achieved in ITER [1] and future devices such as DEMO to dissipate most of the power in the Scrape-Off-Layer (SOL) and reduce the particle flux reaching the divertor targets. In order to enhance our capability to improve current, and design future tokamaks, we must improve our understanding of the relative effect on det…
Preprint PublishedM. Maslov J. Citrin P. Jacquet Y. Kazakov D. L. Keeling D. B. King E. Lerche M. Marin J. Ongena D. Van Eester
As part of the preparation for the second JET DT campaign (DTE2), a series of isotope control experiments in H/D mixtures [1] have shown that NBI fuelling species has only a weak effect on the core isotope composition, which remains determined by the edge H/D ratio and therefore by the injected gas.
Preprint PublishedA. R. Field P. Carvalho L. Garzotti E. Lerche C. Maggi F. Rimini C. Roach S. Saarelma M. Sertoli JET contributors
In high-performance, ITER baseline-scenario pulses (3MA/2.7T) in JET-ILW with high levels (~ 32 MW) of heating power, typically ~ 20-40% of the input power is radiated, predominantly by W impurities, which are sputtered from the divertor targets and reach the confined plasma. Sustained ELMy H-mode operation at such high heating power in JET-ILW req…
Preprint PublishedC.D. Challis S. Brezinsek I. Coffey N. Hawkes D. Keeling D. King G. Pucella E. Viezzer JET Contributors
The initial Ohmic current ramp phase of JET hybrid plasmas, including a current ‘overshoot’ before the main heating, is used to optimise the q-profile shape to allow access to high β and avoid MHD instabilities [1]. Such hybrid plasmas have never been operated using tritium (T) or mixed deuterium-tritium (D-T) fuel. However, experiments with i…
Preprint PublishedJ. S. Edwards I. S. Carvalho R. Felton C. Hogben D. Karkinsky P. J. Lomas P. A. McCullen F. G. Rimini A. V. Stephen
The JET Real-Time Protection Sequencer (RTPS) co-ordinates responses for magnetic and kinetic actuators to protect the ITER-Like Wall from possible melting events and other undesirable scenarios. It allows programmable stop responses per pulse, based on alarms raised by other systems. The architecture combines a modular run-time application deve…
Preprint PublishedS. I. Muldrew H. Lux V. Menon R. Srinivasan
Systems codes assess the viability of fusion reactor designs by using simplified models for the entire reactor system that allow for the exploration of large areas of parameter space. However, every design will have an associated uncertainty that arises from the accuracy of the models used, the assumptions made and the values of input parameters ad…
Preprint PublishedTim Eade Bethany Colling Jonathan Naish Lee Packer Alex Valentine
Shutdown dose rate calculations provide an essential input to the design and research of fusion power plant technology. They allow the estimation of dose to personnel and equipment during planned and unplanned maintenance. The mesh coupled rigorous 2 step (MCR2S) methodology used at Culham Centre for Fusion Energy (CCFE) was originally developed to…
Preprint PublishedF.J. Casson H. Patten C. Bourdelle S. Breton J. Citrin F. Koechl C. Angioni Y. Baranov R. Bilato E.A. Belli C.D. Challis G. Corrigan A. Czarnecka O. Ficker L. Frassinetti L. Garzotti M. Goniche J.P. Graves T. Johnson K. Kirov P. Knight E. Lerche M. Mantsinen J. Mylnar M. Sertoli M. Valisa
The evolution of the JET high performance hybrid scenario, including central accumulation of the tungsten (W) impurity, is reproduced with predictive multi-channel integrated modelling over multiple confinement times using first-principle based models. 8 transport channels are modelled predictively, with self-consistent sources, radiation and magne…
Preprint PublishedS. S. Henderson M. Bernert S. Brezinsek M. Carr M. Cavedon R. Dux D. S. Gahle J. Harrison B. Lipschultz B. Lomanowski A. Meigs M. O’Mullane F. Reimold M. L. Reinke S. Wiesen the EUROfusion MST1 team the ASDEX Upgrade team JET contributors
Reducing the plasma power exhaust impacting on plasma facing components during steady state operation is one of the major design issues in future tokamaks such as ITER. Impurity seeding, e.g. with N, is one method of achieving this and has been used for a long time in tokamak research [1]. In this work we exploit a recently developed spectroscopic …
Preprint Published