Showing 1 - 10 of 134 Journals Results
2020
UKAEA-CCFE-PR(20)131
R.A. Tinguely P.G. Puglia N. Fil S. Dowson M. Porkolab A. Dvornova A. Fasoli M. Fitzgerald G.T.A. Huysmans M. Maslov S. Sharapov D. Testa JET Contributors
This paper presents a dedicated study of plasma-antenna (PA) coupling with the Alfvén Eigenmode Active Diagnostic (AEAD) in JET. Stable AEs and their resonant frequencies f, damping rates < 0, and toroidal mode numbers n are measured for various PA separations and limiter versus X-point magnetic con gurations. Two stable AEs are observed to …
Preprint2020
UKAEA-CCFE-PR(20)118
G. Pucella E. Giovannozzi P. Buratti E. Alessi F. Auriemma D. Brunetti P. J. Lomas S. Nowak C. Sozzi JET Contributors
In this work the mechanisms that can lead to disruptive MHD instabilities in the termination phase of plasma pulses on JET are investigated. It is shown that the broadening or the shrinking of the current density profile, as a consequence of a core hollowing or a e…
Preprint2020
UKAEA-CCFE-PR(20)114
K. K. Kirov E. Belonohy C. D. Challis J. Eriksson D. Frigione L. Garzotti L. Giacomelli J. Hobirk A. Kappatou D. Keeling D. King E. Lerche P. J. Lomas M. Nocente C. Reux F. G. Rimini A. C. C. Sips D. Van Eester JET Contributors
Achieving high neutron yields in today’s fusion research relies on high power auxiliary heating in order to attain required core temperatures. This is usually achieved by means of high Neutral Beam (NB) and Radio Frequency (RF) power. Application of NB power is accompanied by production of fast beam ions and associated Beam-Target (BT) reactio…
Preprint Published2020
UKAEA-CCFE-PR(20)93
Jaemin Seo J. Kim J. Mailloux R.J. Dumont M. Fitzgerald S.E. Sharapov D.L. Keeling F. Koechl F.J. Casson C.Y. Lee T.S. Hahm Y.-S. Na JET contributors
Parametric dependencies of the linear stability of toroidal Alfven eigenmode (TAE) in the presence of neutral beam injection (NBI) are investigated to understand the beam drive and damping effect of TAEs in JET and KSTAR. It is found that the results depend on the drift orbit width of the beam-ions normalized to the characteristic mode widths. I…
Preprint Purchase2020
UKAEA-CCFE-PR(20)83
R.A. Tinguely P.G. Puglia N. Fil S. Dowson M. Porkolab A. Fasoli D. Testa JET Contributors
This paper presents results of extensive analysis of mode excitation observed during the operation of the Alfvén Eigenmode Active Diagnostic (AEAD) in the JET tokamak during the 2019-2020 deuterium campaign. Six of eight toroidally-spaced antennas, each with independent power and phasing, were successful in actively exciting stable MHD modes in…
Preprint Purchase2020
UKAEA-CCFE-PR(20)75
V. Aslanyan S. Taimourzadeh L. Shi Z. Lin G. Dong P. Puglia M. Porkolab R. Dumont S. E. Sharapov J. Mailloux M. Tsalas M. Maslov A. Whitehead R. Scannell S. Gerasimov S. Dorling S. Dowson H. K. Sheikh T. Blackman G. Jones A. Goodyear K. K. Kirov P. Blanchard A. Fasoli D. Testa JET Contributors
The Gyrokinetic Toroidal Code (GTC) has been used to study Toroidal Alfven Eigenmodes (TAEs) in high- performance plasmas. Experiments performed at the Joint European Torus, where TAEs were driven by energetic particles arising from Neutral Beams, ion cyclotron resonant heating and resonantly excited by ded…
Preprint Published2019
UKAEA-CCFE-PR(20)127
S. Saarelma L. Frassinetti P. Bilkova C.D. Challis A. Chankin R. Fridström L. Garzotti L. Horvath C.F. Maggi JET Contributors
The self-consistent core-pedestal prediction model of a combination of EPED1 type pedestal prediction and a simple stiff core transport model is able to predict type I ELMy pedestals of a large database JET-ILW (ITER-like wall) at the similar accuracy as is obtained when the experimental global plasma b is used as input. The neutral penetration …
Preprint Published2019
UKAEA-CCFE-PR(20)122
K.L. van de Plassche J. Citrin C. Bourdelle Y. Camenen F. J. Casson V.I. Dagnelie F. Felici A. Ho JET Contributors
We present an ultrafast neural network (NN) turbulent tokamak transport model, QLKNN, for heat and particle fluxes. QLKNN is a surrogate model based on a database of 3 · 108 flux calculations of the quasilinear gyrokinetic transport model QuaLiKiz. To ensure accurate reproduction of the underlying model, we include known features of the…
Preprint Published2019
UKAEA-CCFE-PR(20)17
M Marin J Citrin C Bourdelle Y Camenen F J Casson A Ho F Koechl M Maslov JET Contributors
Core turbulent particle transport with multiple isotopes can display observable differences in behaviour between the electron and ion particle channels. Experimental observations at JET with mixed H-D plasmas and varying NBI and gas-puff sources [M. Maslov et al., Nucl. Fusion 7 076022 (2018)] inferred source dominated electr…
Preprint Purchase2018
UKAEA-CCFE-PR(20)129