P.K. Browning A. Stanier G. Ashworth K.G. McClements V.S. Lukin
Merging-compression start-up in the Mega Ampere Spherical Tokamak provides an opportunity to investigate the merging of flux ropes through magnetic reconnection, and the self-organization into a single flux rope, in a low-plasma-ß, high-Lundquist-number plasma. We present an overview of simulations of this process using the compressible Hall-MHD e…
PublishedT. O’Gorman G. Naylor R. Scannell G. Cunningham K. J. Brunner R. Martin D. Croft
A single chord two-color CO2/HeNe (10.6/0.633 µm) heterodyne laser interferometer has been designed to measure the line integral electron density along the mid-plane of the MAST Upgrade tokamak, with a typical error of 1 × 1018 m-3 (~2 phase error) at 4 MHz temporal resolution. To ensure this diagnostic system can be restored from any failures wi…
PublishedE. Lerche D. Van Eester Ph. Jacquet M.-L. Mayoral V. Bobkov L. Colas A. Czarnecka M. Graham G. Matthews I. Monakhov R. Neu T. Puetterich F. Rimini P. De Vries JET-EFDA Contributors
After the change over from the C-wall to the ITER-like Be/W wall (ILW) in JET, the radiation losses during ICRF heating have increased and are now substantially larger than those observed with NBI at the same power levels, in spite of the similar global plasma energies reached with the two heating systems. A comparison of the NBI and ICRF performan…
PublishedV. G. Kiptily P. Beaumont F. Belli F. E. Cecil S. Conroy T. Craciunescu M. Garcia-Munoz M. Curuia D. Darrow Et. Al.
JET equipped with ITER-like wall (a beryllium wall and a tungsten divertor) can provide auxiliary heating with power up to 35MW, producing a significant population of alpha-particles in DT operation. The direct measurements of alphas are very difficult and alpha-particle studies require a significant development of dedicated diagnostics. JET now ha…
PublishedD. Taylor S. Lilley A. Turner A. Davis
A significant functional upgrade is planned for the Mega Ampere Spherical Tokamak (MAST) device, located at Culham in the UK, including the implementation of a notably greater neutral beam injection power. This upgrade will cause the emission of a substantially increased intensity of neutron radiation for a substantially increased amount of time up…
PublishedA.J. Webster R.O. Dendy F.A. Calderon S. C. Chapman E. Delabie D. Dodt R. Felton T. N. Todd F. Maviglia J. Morris V. Riccardo B. Alper S. Brezinsek P. Coad J. Likonen M. Rubel JET EFDA Contributors
For a two week period during the Joint European Torus (JET) 2012 experimental campaign, the same high confinement plasma was repeated 151 times. The dataset was analysed to produce a probability density function (pdf) for the waiting times between edge-localised plasma instabilities (“ELMs”). The result was entirely unexpected. Instead of a smo…
PublishedF. Militello M. Ottaviani A. Wynn
Unstable electrostatic resistive modes, driven by density gradients, are identified in a bounded sheared slab. The boundary conditions play a crucial role and are shown to change the nature of the problem, which is related to so called “universal” mode. The dispersion relation and the structure of the eigenmodes of the instability are derived a…
PublishedYuling He Yueqiang Liu Yue Liu Guangzhou Hao Aike Wang
An energy-principle-based dispersion relation is derived for the resistive wall mode, which incorporates both the drift kinetic resonance between the mode and energetic particles and the resistive layer physics. The equivalence between the energy-principle approach and the resistive layer matching approach is first demonstrated for the resistive pl…
PublishedR. McAdams
A high pumping speed is required in neutral beam injectors to minimise re-ionisation of the neutral beams. The neutral beam injectors on MAST use titanium sublimation pumps. These pumps do not have a constant pumping speed; their pumping speed depends on the gettering surface history and on both the integrated and applied gas load. In this paper we…
Preprint Published