R. B. Morales A. Salmi P. Abreu C. H. S. Amador P. Carman J. Fessey J. Flanagan M. Fontana C. Giroud S. Hacquin S. Heuraux L. Meneses R. Sabot A. Silva A. Sirinelli G. Szepesi D. Taylor D. Terranova
JET’s frequency-modulated continuous-wave (FMCW) reflectometers have been operating well with the current design since 2005 and density profiles are being automatically calculated intershot since then[1]. However, the calculated profiles had long suffered from several shortcomings – poor agreement to other diagnostics; sometimes inappropriat…
PreprintG. Giruzzi M. Fontana F.P. Orsitto E. de la Luna R. Dumont L. Figini M. Maslov S. Mazzi S. Schmuck L. Senni C. Sozzi C. Challis D. Frigione J. Garcia L. Garzotti J. Hobirk A. Kappatou D. Keeling E. Lerche C. Maggi J. Mailloux F. Rimini D. Van Eester JET contributors
Recent experiments performed in JET at high level of plasma heating, in preparation of, and during the DT campaign have shown significant discrepancies between electron temperature measurements by Thomson Scattering (TS) and Electron Cyclotron Emission (ECE). In order to perform a systematic analysis of this effect, a simple model of bipolar dis…
PreprintM. Fontana G. Giruzzi F. P. Orsitto E. de la Luna R. Dumont L. Figini D. Kos M. Maslov S. Schmuck C. Sozzi JET contributors
Accurate and consistent measurements of the electron temperature (Te) profile are paramount for current fusion experiments, like JET, and future devices, such as ITER. In high performance plasmas in JET and TFTR, electron cyclotron emission (ECE) measurements for central Te>5 keV were systematically found to be up to 20%…
PreprintD. Brunetti C. J. Ham J. P. Graves E. Lazzaro S. Nowak A. Mariani C. Wahlberg W. A. Cooper E. R. Solano S. Saarelma L. Frassinetti M. Fontana A. Kleiner G. Bustos Ramirez E. Viezzer JET contributors
The analysis of quiescent discharges exhibiting edge harmonic magnetoydrodynamic activity in the JET-Carbon wall machine is presented. It is observed that the quiescent phase with multiple-n harmonic oscillations is sustained until a threshold in pedestal electron density and collisionality is crossed. The macroscopic pedestal parameters associated…
Preprint PublishedC.D. Challis J. Hobirk A. Kappatou E. Lerche F. Auriemma E.Belonohy I. Coffey J. Eriksson A. Field M.Fontana J.Garcia A. Ho F. Jaulmes D. Keeling D. King K. Kirov M. Lennholm C.Maggi J.Mailloux M. Maslov S. Menmuir G. Pucella E. Rachlew F. Rimini A. Sahlberg A.Sips E. Solano C. Stuart M. Valisa
A key aim of the 2021 JET deuterium-tritium (D-T) experiments was to demonstrate steady high fusion power (10-15MW) with the ITER-like Be/W first wall. Plasmas were developed using D, repeated with T to investigate and mitigate isotope effects, and run with D-T to maximise fusion power. Compared with high current (q95~3) ‘baseline’ plasmas, …
PreprintB. Geiger A. N. Karpushov S. Sharapov R. Akers A. Bock M. Dunne B. Duval M. Fontana L. Giannone J. Hobirk C. Hopf A.S. Jacobsen D. Keeling P. Lauber C. Marini P. ZS. Poloskei M. Salewski O. Sauter P. A. Schneider D. Testa A.J. Van Vuuren M. Willensdorfer TCV Team ASDEX Upgrade Team EUROfusion MST15 Team
The fast-ion transport has been investigated in low-collisionality discharges at ASDEX Upgrade and TCV using offaxis neutral beams. In both devices Alfven eigenmode activity was observed which does, however, not strongly affect the global fast-ion confinement. In contrast, charge exchange losses have been identified to have a strong effect. At TCV …
PreprintC.D. Challis S. Brezinsek I. Coffey M. Fontana N. Hawkes D. Keeling D. King G. Pucella E. Viezzer JET Contributors
The initial current ramp phase of JET hybrid plasmas is used to optimise the target q-profile for main heating to allow access to high beta and avoid MHD instabilities. Mixed protium-deuterium experiments, carried out at JET since the installation of the beryllium-tungsten wall, have shown that the q-profile evolution during this Ohmic phase varies…
Preprint Published