C.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 PublishedV. Riccardo G. Arnoux S. Collins P. Lomas G. Matthews N. Pace V. Thompson JET EFDA Contributors
The JET ITER-like Wall (ILW) provides the same plasma facing component configuration as ITER during its active phase: beryllium in the main chamber and tungsten in the divertor. Moving from a carbon-based wall to an all metal wall requires some operational adjustment. The reduction in radiation at the plasma edge and in the divertor can lead to hig…
PublishedP. C. De Vries M. Baruzzo G. M. D. Hogeweij S. Jachmich E. Joffrin P. J. Lomas G. F. Matthews A. Murari I. Nunes T. Pütterich C. Reux J. Vega JET-EFDA Contributors
In order to preserve the integrity of large tokamaks such as ITER, the number of disruptions has to be limited. JET has operated previously with a low frequency of disruptions (i.e., disruption rate) of 3.4% [P. C. de Vries et al., Nucl. Fusion 51, 053018 (2011)]. The start of operations with the new full-metal ITER-like wall at JET showed a marked…
PublishedG. Arnoux I. Balboa M. Clever S. Devaux P. De Vries T. Eich M. Firdaouss S. Jachmich M. Lehnen P.J. Lomas G.F. Matthews Ph. Mertens I. Nunes V. Riccardo C. Ruset B. Sieglin D.F. Valcarcel J. Wilson K.-D. Zastrow JET-EFDA Contributors
The ITER-like wall (ILW) at JET is a unique opportunity to study the combination of material (beryllium and tungsten) that will be used for the plasma facing components (PFC) in ITER. Both the limiters (Be) and divertor (CFC W coated and bulk W) have been designed to maximise their power handling capability. During the last experimental campaign (O…
PublishedV Riccardo P Lomas G F Matthews I Nunes V Thompson E Villedieu JET EFDA Contributors
The aim of the JET ITER-like Wall Project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions. The design of the bulk Be plasma fa…
PublishedD. Alves R. Felton S. Jachmich P. Lomas P. Mccullen A. Neto D. F. Valcárcel G. Arnoux P. Card S. Devaux A. Goodyear D. Kinna A. Stephen K.-D. Zastrow
The installation of international thermonuclear experimental reactor-relevant materials for the plasma facing components (PFCs) in the Joint European Torus (JET) is expected to have a strong impact on the operation and protection of the experiment. In particular, the use of all-beryllium tiles, which deteriorate at a substantially lower temperature…
PublishedA S Kaye H Altmann R Albanese D Ciric P Coad D Brennan F Durodie T Edlington D C Edwards R Felton T T C Jones A Lioure P Lomas J Mailloux I Monakhov M Nightingale J Pamela R Pearce V Riccardo J Rapp A Rolfe E Surrey S Rosanvallon T Todd, A Walden
JET supports ITER both in development of technology and in torus operations. The latter include the study of ITER-like scenarios, operation in tritium (a trace tritium campaign has recently been completed), mitigation of ELMs and disruptions, investigation of tritium retention, real time control of plasma parameters, and control of extreme plasma s…
PublishedN. C. Hawkes B. C. Stratton T. Tala C. D. Challis G. Conway R. Deangelis C. Giroud J. Hobirk E. Joffrin P. Lomas P. Lotte J. Mailloux D. Mazon E. Rachlew S. Reyes-Cortes E. Solano K-D. Zastrow
Simultaneous current ramping and application of lower hybrid heating and current drive (LHCD) have produced a region with zero current density within measurement errors in the core of JET tokamak optimized shear discharges. The reduction of core current density is consistent with a simple physical explanation and numerical simulations of radial cur…
PublishedN. C. Hawkes B. C. Stratton T. Tala C. D. Challis G. Conway R. Deangelis C. Giroud J. Hobirk E. Joffrin P. Lomas P. Lotte J. Mailloux D. Mazon E. Rachlew S. Reyes-Cortes E. Solano K-D. Zastrow
Modern charge-coupled-device (CCD) detectors can achieve peak quantum efficiencies of 90%, compared with less than 10% for the photocathode of an electron multiplier. We report on laboratory tests of examples of these two detector technologies to evaluate their relative performance for precision Doppler spectroscopy of laboratory plasmas. The tests…
Published