A. J. Webster R. O. Dendy
The statistics of edge-localized plasma instabilities (ELMs) in toroidal magnetically confined fusion plasmas are considered. From first principles, standard experimentally motivated assumptions are shown to determine a specific probability distribution for the waiting times between ELMs: the Weibull distribution. This is confirmed empirically by a…
PublishedAnthony J. Webster Richard Kemp
The mark-recapture method was devised by Petersen in 1896 to estimate the number of fish migrating into the Limfjord, and independently by Lincoln in 1930 to estimate waterfowl abundance. The technique can be applied to any search for a finite number of items by two or more people or agents, allowing the number of searched-for items to be estimated…
PublishedM.Yu. Lavrentiev D. Nguyen-Manh J. Wrobel S.L. Dudarev
We develop a Magnetic Cluster Expansion (MCE) model for binary bcc and fcc Fe–Cr alloys, as well as for fcc Fe-Ni alloys, and apply it to the investigation of magnetic properties of these alloys over a broad interval of concentrations, and over a broad interval of temperatures extending well over 1000 K. We show how an MCE-based Monte Carlo study…
PublishedJ. R. Robinson B. Hnat A. Thyagaraja K. G. McClements P. J. Knight et al.
Following recent observations suggesting the presence of the geodesic acoustic mode (GAM) in ohmically heated discharges in the Mega Amp Spherical Tokamak (MAST) [J. R. Robinson et al., Plasma Phys. Controlled Fusion 54, 105007 (2012)], the behaviour of the GAM is studied numerically using the two fluid, global code CENTORI [P. J. Knight et al. Com…
PublishedA.G. Meigs S. Brezinsek M. Clever A. Huber S. Marsen C. Nicholas M.Stamp K-D Zastrow JET EFDA Contributors
For the ITER-like wall, the JET mirror link divertor spectroscopy system was redesigned to fully cover the tungsten horizontal strike plate with faster time resolution and improved near-UV performance. Since the ITER-like wall project involves a change in JET from a carbon dominated machine to a beryllium and tungsten dominated machine with residua…
PublishedN Sykes C Belcher C-H Choi O Crofts R Crowe C Damiani S Delavalle L Meredith T Mindham J Raimbach A Tesini M Van Uffelen
The ITER neutral beam cell will contain up to three heating neutral beams and one diagnostic neutral beam, and four upper ports. Though manual maintenance work is envisaged within the cell, when containment is breached, or the radiological protection is removed the maintenance must be conducted remotely. This maintenance constitutes the removal and…
PublishedH.J. Van Der Meiden M. A. Van Den Berg S. Brons H. Ding H.J.N. Van Eck M.H.J. T Hoen Et Al
Several laser based diagnostics are implemented on to the linear plasma generator Magnum-PSI, wherein ITER divertor relevant plasma-wall conditions are realized. Laser Induced Desorption Quadrupole Mass Spectroscopy (LID-QMS) and Laser Induced Breakdown Spectroscopy (LIBS) are installed to measure deuterium retention in plasma facing components. Co…
PublishedT. D. Swinburne S. L. Dudarev S. P. Fitzgerald M. R. Gilbert A. P. Sutton
Isolated kinks on thermally fluctuating 1/2 111 screw, 100 edge, and 1/2 111 edge dislocations in bcc iron are simulated under zero stress conditions using molecular dynamics (MD). Kinks are seen to perform stochastic motion in a potential landscape that depends on the dislocation character and geometry, and their motion provides fresh insight …
PublishedF. Orain M. Bécoulet G. Dif-Pradalier G. Huijsmans S. Pamela E. Nardon C. Passeron G. Latu V. Grandgirard A. Fil A. Ratnani I. Chapman A. Kirk A. Thornton M. Hoelzl P. Cahyna
The interaction of static Resonant Magnetic Perturbations (RMPs) with the plasma flows is modeled in toroidal geometry, using the non-linear resistive MHD code JOREK, which includes the X-point and the scrape-off-layer. Two-fluid diamagnetic effects, the neoclassical poloidal friction and a source of toroidal rotation are introduced in the model to…
PublishedN. F. Loureiro A. A. Schekochihin A. Zocco
Magnetic reconnection in strongly magnetized (low-beta), weakly collisional plasmas is investigated by using a novel fluid-kinetic model [Zocco and Schekochihin, Phys. Plasmas 18, 102309 (2011)] which retains nonisothermal electron kinetics. It is shown that electron heating via Landau damping (linear phase mixing) is the dominant dissipation mecha…
Published