Luca Garzotti C. Challis R. Dumont D. Frigione J. Graves E Lerche J. Mailloux M. Mantsinen F. Rimini F. Casson A. Czarnecka J. Eriksson R. Felton L. Frassinetti D. Gallart J. Garcia C. Giroud E. Joffrin H.-T. Kim N. Krawczyk M. Lennholm P. Lomas C. Lowry L. Meneses I. Nunes C. M. Roach M. Romanelli S. Sharapov S. Silburn A. Sips E. Stefanikova M. Tsalas D. Valcarcel M. Valovic JET contributors
The JET exploitation plan foresees D-T operations in 2020 (DTE2). With respect to the first D-T campaign in 1997 (DTE1), when JET was equipped with a carbon wall, the experiments will be conducted in presence of a beryllium-tungsten ITER-like wall (ILW) and will benefit from an extended and improved set of diagnostics and higher additional heating …
Preprint PublishedL. Horvath C.F. Maggi F.J. Casson V. Parail L. Frassinetti F. Koechl S. Saarelma M.G. Dunne K.J. Gibson JET Contributors
Recent studies have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high beta discharges with high D2 gas rates the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the Peeling-Ballooni…
Preprint PublishedS.Pamela G.Huijsmans T.Eich S.Saarelma I.Lupelli C.Maggi C.Giroud I.Chapman S.F.Smith L.Frassinetti M.Becoulet M.Hoelzl F.Orain S.Futatani JET Contributors
Future devices like JT-60SA, ITER and DEMO require quantitative predictions of pedestal density and temperature levels, as well as inter-ELM and ELM divertor heat fluxes, in order to improve global confinement capabilities while preventing divertor erosion/melting in the planning of future experiments. Such predictions can be obtained from dedicate…
Preprint PublishedH. T. Kim M. Romanelli X. Yuan S. Kaye A.C.C. Sips L. Frassinetti J. Buchanan JET Contributors
This paper presents for the first time a statistical validation of predictive TRANSP simulations of plasma temperature using two transport models, GLF23 and TGLF, over a database of 80 baseline H-mode discharges in JET-ILW. While the accuracy of the predicted Te with TRANSP-GLF23 is affected by plasma collisionality, the dependency of predictions o…
Preprint PublishedS. Pamela T. Eich L. Frassinetti B. Sieglin S. Saarelma G. Huijsmans M. Hoelzl M. Becoulet F. Orain S. Devaux I. Chapman I. Lupelli E. Solano JET Contributors
A subset of JET ITER-like wall (ILW) discharges, combining electron density and temperature as well as divertor heat flux measurements, has been collected for the validation of non-linear MHD simulations of Edge-Localised-Modes (ELMs). This permits a quantitative comparison of simulation results against experiments, which is required for the valida…
Preprint PublishedM. J. Leyland M. N. A. Beurskens J. C. Flanagan L. Frassinetti K. J. Gibson M. Kempenaars M. Maslov R. Scannell JET Contributors
The Joint European Torus (JET) high resolution Thomson scattering (HRTS) system measures radial electron temperature and density profiles. One of the key capabilities of this diagnostic is measuring the steep pressure gradient, termed the pedestal, at the edge of JET plasmas. The pedestal is susceptible to limiting instabilities, such as Edge Local…
Preprint PublishedC.F. Maggi S. Saarelma F.J. Casson C. Challis E. de la Luna L. Frassinetti C. Giroud E. Joffrin J. Simpson M. Beurskens I. Chapman J. Hobirk M. Leyland P. Lomas C. Lowry I. Nunes F. Rimini A.C.C. Sips H. Urano JET Contributors
New experiments in 2013-2014 have investigated the physics responsible for the decrease in H-mode pedestal confinement observed in the initial phase of JET-ILW operation (2012 Experimental Campaigns). The effects of plasma triangularity, global beta and neutrals on pedestal confinement and stability have been investigated systematically. The stabil…
Preprint PublishedC.D. Challis J. Garcia M. Beurskens P. Buratti E. Delabie P. Drewelow L. Frassinetti C. Giroud N. Hawkes J. Hobirk E. Joffrin D. Keeling D.B. King C.F. Maggi J. Mailloux C. Marchetto D. McDonald I. Nunes G. Pucella S. Saarelma J. Simps
The replacement of the JET carbon wall (C-wall) by a Be/W ITER-like wall (ILW) has affected the plasma energy confinement. To investigate this, experiments have been performed with both the C-wall and ILW to vary the heating power over a wide range for plasmas with different shapes. It was found that the power degradation of thermal energy confinem…
Preprint PublishedS. Saarelma A. Järvinen M. Beurskens C. Challis L. Frassinetti C. Giroud M. Groth M. Leyland C. Maggi J. Simpson JET Contributors
The H-mode pedestal plays an important role in determining global confinement in tokamaks. In high triangularity H-mode experiments in Joint European Torus with the ITER-like wall (JET-ILW), significantly higher pedestal temperature and global confinement have been achieved with nitrogen seeding. The experimentally observed increase in pedestal hei…
Preprint PublishedP. Bohm M. Aftanas P. Bilkova E. Stefanikova O. Mikulin R. Melich F. Janky J. Havlicek D. Sestak V. Weinzettl J. Stockel M. Hron R. Panek R. Scannell L. Frassinetti A. Fassina G. Naylor M. J. Walsh
The core Thomson scattering diagnostic (TS) on the COMPASS tokamak was put in operation and reported earlier. Implementation of edge TS, with spatial resolution along the laser beam up to~1/100 of the tokamak minor radius, is presented now. The procedure for spatial calibration and alignment of both core and edge systems is described. Several furth…
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