I. Balboa E. Rose G. F. Matthews D. Croft M. Stamp S. A. Silburn J. C. Williams D. Hepple A. Huber S. Whetham D. Iglesias D. J. Kinna M. Beldishevski J. Figueiredo C. Perez Von Thun G. Jones N. Balshaw L. D. Horton R. C. Lobel I. J. Pearson K. W. Pepperell G. Fishpool B. Lane K-D. Zastrow G. Arnoux G. Bodnar P. Carman N. J. Conway N. Gupta V. Huber G. Kocsis A. Manzanares C. Ruiz de Galarreta C. Marren R. Otín J. Naish V. K. Thompson JET Contributors
This article starts with a brief description of two new viewing systems with a light path which crosses the biological shield wall and are compatible with Deuterium-Tritium (D-T) operations in JET. However, it focuses on the optical modelling and engineering design of one of them which is a multiple camera system producing a wide angle view (WAV)…
Preprint PurchaseI. Balboa E. Rose G. F. Matthews D. Croft M. Stamp S. A. Silburn J. C. Williams D. Hepple A. Huber S. Whetham D. Iglesias D. J. Kinna M. Beldishevski J. Figueiredo C. Perez Von Thun N. Balshaw L. D. Horton R. C. Lobel I. J. Pearson K. W. Pepperell G. Fishpool B. Lane K-D. Zastrow G. Arnoux G. Bodnar P. Carman P. Carvalho N. J. Conway V. Huber J. Karhunen G. Kocsis A. Manzanares P. Puglia C. Ruiz de Galarreta C. Marren R. Otín J. Naish V. K. Thompson the JET Contributors*
Following from the paper describing the remote wide angle viewing system compatible with Deuterium-Tritium operations. This is the second article describing a second remote line of sight, this time focusing on the imaging of the divertor region in JET. It explains in detail the optical and engineering designs of constructing an optical relay which …
PreprintM. Fitzgerald R. Dumont D. Keeling J. Mailloux S. Sharapov M. Dreval A. Figueiredo R. Coelho J. Ferreira P. Rodrigues F. Nabais D. Borba Ž. Štancar G. Szepesi R.A. Tinguely N Fil P.G. Puglia H.J.C. Oliver V. Kiptily M. Baruzzo M. Lennholm P. Siren J. Garcia C.F. Maggi
A toroidal Alfven eigenmode (TAE) has been observed driven by alpha particles in the Joint European Torus (JET). The observation was made in dedicated deuterium-tritium experiments where radio-frequency (RF) heating was absent, in the so-called “afterglow” period when neutral beam heating was removed. Agreement with reduced and perturbative mod…
PreprintM. Fitzgerald S. E. Sharapov P. Siren E. Tholerus M. Dreval G. Szepesi P. Olivares T. Jonsson N. Fil J. Ferreira P. Rodrigues A. Figueiredo D. Borba R. Coelho F. Nabais J. Mailloux H.J.C. Oliver C. Di Troia F. Napoli Z. Stancar R. Dumont D. Keeling
In this work, we use reduced and perturbative models to examine the stability of TAEs during the ITB afterglow in JET experiments designed for the observation of alpha driven TAEs. We demonstrate that in JET-like conditions, it is sufficient to use an incompressible cold plasma model for the TAE to reproduce the experimental adiabatic features…
PreprintS. Dowson S. Dorling H. K. Sheikh T. Blackman G. Jones A. Goodyear P. Puglia P. Blanchard A. Fasoli D. Testa N. Fil V. Aslanyan M. Porkolab W. Pires De Sa R. Galvao L. Ruchko J. Figueiredo C. Perez Von Thun JET Contributors
The Alfvén Eigenmode Active Diagnostic system (AEAD) has undergone a major upgrade and redesign to provide a state of the art excitation and real-time detection system for JET. The new system consists of individual 4kW amplifiers for each of the six antennas, allowing for increased current, separate excitation and real time control of relative …
Preprint PublishedJ. Figueiredo J. Mailloux K. Kirov D. Kinna M. Stamp S. Devaux G. Arnoux J. S. Edwards A. V. Stephen P. Mccullen C. Hogben JET EFDA Contributors
Arcs are the potentially most dangerous events related to Lower Hybrid (LH) antenna operation. If left uncontrolled they can produce damage and cause plasma disruption by impurity influx. To address this issue an arc real time control and protection imaging system for the Joint European Torus (JET) LH antenna has been implemented. The LH system is …
PublishedL. Garzotti J. Figueiredo C. M. Roach M. Valovic D. Dickinson G. Naylor M. Romanelli R. Scannell G. Szepesi The Mast Team
Reactor grade plasmas are likely to be fuelled by pellet injection. This technique transiently perturbs the profiles, driving the density profile hollow and flattening the edge temperature profile. After the pellet perturbation, the density and temperature profiles relax towards their quasi-steady-state shape. Microinstabilities influence plasma co…
PublishedP. Mantica C. Angioni C. Challis G. Colyer L. Frassinetti N. Hawkes T. Johnson M. Tsalas P. C. Devries J. Weiland B. Baiocchi M. N. A. Beurskens A. C. A. Figueiredo C. Giroud J. Hobirk E. Joffrin E. Lerche V. Naulin A. G. Peeters A. Sal
New transport experiments on JET indicate that ion stiffness mitigation in the core of a rotating plasma, as described by Mantica et al. [ Phys. Rev. Lett. 102, 175002 (2009) ] results from the combined effect of high rotational shear and low magnetic shear. The observations have important implications for the understanding of improved ion core con…
PublishedJ. Figueiredo G. Naylor M. Walsh M. Dunstan R. Scannell F. Serra
The recent upgrade to the MAST YAG Thomson scattering while enhancing the diagnostic capabilities increased the complexity of the system. There are eight YAG lasers now operational, doubling the number from the previous setup. This means alignment between each laser individually and reference points is essential to guarantee data quality and diagno…
PublishedR. Scannell M. J. Walsh M. R. Dunstan J. Figueiredo G. Naylor T. O’Gorman K. J. Gibson H. Wilson S. Shibaev
A Thomson scattering diagnostic designed to measure both edge and core physics has been implemented on MAST. The system uses eight Nd:YAG lasers, each with a repetition rate of 30 Hz. The relative and absolute timing of the lasers may be set arbitrarily to produce fast bursts of measurements to suit the time evolution of the physics being studied. …
Published