L. Piron B. Zaniol D. Bonfiglio L. Carraro A. Kirk L. Marrelli R. Martin C. Piron P. Piovesan M. Zuin
This work presents the first evidence of helical flow in RFX-mod q(a) < 2 tokamak plasmas. The flow pattern is characterized by the presence of convective cells with m = 1 and n = 1 periodicity in the poloidal and toroidal direction, respectively. A similar helical flow deformation has been observed in the same device when operatedfas a Reversed…
Preprint PublishedJ. Milnes N.B. Ayed F. Dhalla G. Fishpool J. Hill I. Katramados R. Martin G. Naylor T. O’Gorman R. Scannell The MAST Upgrade team
The Mega Amp Spherical Tokamak (MAST) is the centre piece of the UK fusion research programme.In 2010, a MAST Upgrade programme was initiated with three primary objectives, to contribute to: (1)testing reactor concepts (in particular exhaust solutions via a flexible divertor allowing Super-X and otherextended leg configurations); (2) adding to the …
Preprint 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…
PublishedM. Weiszflog S. Sangaroon M. Cecconello S. Conroy G. Ericsson I. Klimek D. Keeling R. Martin M. Turnyanskiy
This paper presents two different conceptual designs of neutron cameras for Mega Ampere Spherical Tokamak (MAST) Upgrade. The first one consists of two horizontal cameras, one equatorial and one vertically down-shifted by 65 cm. The second design, viewing the plasma in a poloidal section, also consists of two cameras, one radial and the other one w…
PublishedF. Villone G. Calabrò G. Marchiori S. Mastrostefano G. Vlad T. Bolzonella F. Crisanti V. Fusco Y. Q. Liu P. Mantica L. Marrelli P. Martin
One of the main FAST (Fusion Advanced Studies Torus) goals is to have a flexible experiment capable to test tools and scenarios for safe and reliable tokamak operation, in order to support ITER and help the final DEMO design. In particular, in this paper, we focus on operation close to a possible border of stability related to low-q operation. To t…
PublishedA. Kirk Yueqiang Liu R. Martin G. Cunningham D. Howell The Mast Team
The misalignment of field coils in tokamaks can lead to toroidal asymmetries in the magnetic field, which are known as intrinsic error fields. These error fields often lead to the formation of locked modes in the plasma, which limit the lowest density that is achievable. The intrinsic error fields on MAST have been determined by the direct measurem…
PublishedA.J. Thornton K.J. Gibson J.R. Harrison M. Lehnen R. Martin A. Kirk The Mast Team
Disruptions are of significant concern to future devices, due to the large amount of energy released during the rapid quenching of the plasma. Disruption mitigation has been performed on MAST, to study the effect on heat loads and disruption time scales in a spherical tokamak. Massive gas injection is performed using a disruption mitigation valve c…
PublishedC.J. Ham Y.Q. Liu J.W. Connor S.C. Cowley R.J. Hastie T.C. Hender T.J. Martin
Two methods for calculating tearing mode stability are described in this paper. A fast method using the recently improved T7 code (Ham et al. 2012 Plasma Phys. Control. Fusion 54 025009) and a new method based on the MARS-F MHD stability code (Liu et al. 2000 Phys. Plasmas 7 3681) which constructs the tearing mode solution from calculated basis fun…
PublishedW A Cooper J P Graves O Sauter S P Hirshman I T Chapman M Gobbin L Marrelli P Martin I Predebon D Terranova
Magnetohydrodynamic equilibrium states with a three-dimensional helical core are computed to model the MAST spherical tokamak and the RFX-mod reversed field pinch. The boundary is fixed as axisymmetric. The MAST equilibrium state has the appearance of an internal kink mode and is obtained under conditions of weak reversed central shear. The RFX-mod…
Published