M. Gelfusa A. Murari I. Lupelli N. Hawkes P. Gaudio M. Baruzzo M. Brix T. Craciunescu V. Drozdov A. Meigs E. Peluso M. Romanelli S. Schmuck B. Sieglin JET-EFDA Contributors
One of the main approaches to thermonuclear fusion relies on confining high temperature plasmas with properly shaped magnetic fields. The determination of the magnetic topology is, therefore, essential for controlling the experiments and for achieving the required performance. In Tokamaks, the reconstruction of the fields is typically formulated as…
PublishedJ. Hawke R. Scannell M. Maslov J. B. Migozzi JET-EFDA Contributors
This work isolated the cause of the observed discrepancy between the electron temperature (Te) measurements before and after the JET Core LIDAR Thomson Scattering (TS) diagnostic was upgraded. In the upgrade process, stray light filters positioned just before the detectors were removed from the system. Modelling showed that the shift imposed on the…
PublishedHyun-Tae Kim A.C.C. Sips P.C. De Vries JET-EFDA Contributors
This paper will discuss simulations of the full ionization process (i.e. plasma burn-through), fundamental to creating high temperature plasma. By means of an applied electric field, the gas is partially ionized by the electron avalanche process. In order for the electron temperature to increase, the remaining neutrals need to be fully ionized in t…
PublishedK.D. Lawson I.H. Coffey K.M. Aggarwal F.P. Keenan JET-EFDA Contributors
The main populating and depopulating mechanisms of the excited energy levels of ions in plasmas with densities
PublishedI Monakhov M Graham T Blackman S Dowson F Durodie P Jacquet J Lehmann M-L Mayoral M P S Nightingale C Noble H Sheikh M Vrancken A Walden A Whitehurst E Wooldridge JET-EFDA Contributors
A load-tolerant External Conjugate-T (ECT) impedance matching system for two A2 Ion Cyclotron Resonance Heating (ICRH) antennas has been successfully put into operation at JET. The system allows continuous injection of the RF power into plasma in the presence of strong antenna loading perturbations caused by Edge Localized Modes (ELMs). Reliable EC…
PublishedIT Chapman JP Graves O Sauter C Zucca O Asunta RJ Buttery S Coda T Goodman V Igochine T Johnson M Jucker RJ La Haye M Lennholm JET-EFDA Contributors
13MW of electron cyclotron current drive (ECCD) power deposited inside the q = 1 surface is likely to reduce the sawtooth period in ITER baseline scenario below the level empirically predicted to trigger neo-classical tearing modes (NTMs). However, since the ECCD control scheme is solely predicated upon changing the local magnetic shear, it is prud…
PublishedA. Widdowson C.F. Ayres S. Booth J.P. Coad A. Hakola K. Heinola D. Ivanova S. Koivuranta J. Likonen M. Mayer M. Stamp JET-EFDA Contributors
A complete global balance for carbon in JET requires knowledge of the net erosion in the main chamber, net deposition in the divertor and the amount of dust and flakes collecting in the divertor region. This paper describes a number of measurements on aspects of this global picture. Profiler measurements and cross section microscopy on tiles that w…
PublishedS. González J. Vega A. Murari A. Pereira M. Beurskens JET-EFDA Contributors
Massive amounts of data generated by fusion machines (such as JET) require developing automatic methods for data analysis. Edge-localized modes (ELMs) are instabilities occurring in the edge of H-mode plasmas. The aim of this work is to develop an automatic off-line method for identifying and locating ELMs. This method uses Universal Multi-Event Lo…
PublishedAndrea Murari Guido Vagliasindi Sebastiano De Fiore Eleonora Arena Paolo Arena Luigi Fortuna Y. Andrew M. Johnson JET-EFDA Contributors
Dynamical systems are often considered immune from memory effects, i.e., the dependence of their time evolution on the previous history. This assumption has been tested for two phenomena in nuclear fusion that are believed to sometimes show sensitivity to the previous history of the discharge: disruptions and the transition from the L mode to the H…
PublishedJ. Mlynar V. Weinzettl G. Bonheure A. Murari JET-EFDA Contributors
Several diagnostic systems in magnetically confined fusion plasmas provide line-integrated measurements along chords, including bolometry, visible light, soft-Xray ~SXR!, or neutron diagnostics. The task of retrieval of spatial distribution of the plasma emissivity from the line-integrated measurements constitutes an important part of fusion data a…
Published