J. W. Berkery S. A. Sabbagh L. Kogan D. Ryan J. M. Bialek Y. Jiang D. J. Battaglia S. Gibson C. Ham
Reconstructions of plasma equilibria using magnetic sensors and a Dα constraint were routine during operation of the MAST spherical tokamak, but reconstructions using kinetic profiles was not. These are necessary for stability and disruption analysis of the MAST database, as well as going forward for operation in the upgrade to the device, MAST…
Preprint PublishedM. Kong F. Felici O. Sauter C. Galperti T. Vu C. Ham T.C. Hender M. Maraschek M. Reich the TCV team the ASDEX Upgrade team the MAST team the EUROfusion MST1 team
This paper presents recent progress on the studies of neoclassical tearing modes (NTMs) on TCV, concerning the new physics learned and how this physics contributes to a better real-time (RT) control of NTMs. A simple technique that adds a small (sinusoidal) sweeping to the target electron cyclotron (EC) beam deposition location has proven effective…
Preprint PublishedK G McClements J Young L Garzotti O M Jones C A Michael
The work reported in this paper has already been presented internally by placement student Jacob Young at a MAST Physics and Technology meeting on December 17 2020. Therefore it does not require a paper review presentation. Please also note that the paper is proposed for inclusion in a special issue of Plasma Research Express linked to the recent I…
Preprint PublishedM. Knolker T. Osborne E. Belli S. Henderson A. Kirk L. Kogan S. Saarelma P. B. Snyder
In preparation for the upcoming MAST-U campaign, pedestal stability of spherical tokamaks is revisited by investigating standard H-mode discharges on MAST. As a step beyond previous studies, both ion and electron profiles are used for obtaining equilibria and a diverse set of pedestals is evaluated. Stability analysis with the ELITE and CGYRO codes…
Preprint PublishedJ.W. Berkery G. Xia J.M. Bialek S.A. Sabbagh Z.R. Wang C. Ham A. Thornton Y.Q. Liu
Assessment of the limits of stability of tokamak plasmas is key to operation in high fusion performance ranges without disruption of the plasma current. Projected equilibria have been generated for the MAST-U spherical tokamak experiment, an upgrade of the previous MAST device, in order to prepare for operation. These equilibria are scanned in p…
PreprintW.W. Heidbrink A. Garcia W. Boeglin M. Salewski
The weight function W(X) is a diagnostic sensitivity to phase-space variables X that relates the measured signal C to the distribution function F(X) through the equation C = ∫ W(X)F(X)dX. In the present work, an algorithm to calculate W for a diagnostic that measures 3 MeV protons produced in d(d,p)t fusion reactions between a fast ion and a th…
Preprint PublishedJohn Waterhouse
The JET control and data acquisition system (CODAS) is an integrated system that provides all the pulse based and continuous data acquisition, real time and slow control and control room interfaces for JET. It has a long history, dating back to the beginning of JET in 1980. It utilises both commercially available hardware along with many in-house m…
Preprint PublishedS.Hall P.Jacquet G.Naylor
The Mega Amp Spherical Tokamak (MAST) is currently being extensively upgraded to provide a system that will be able to add to the knowledge base for ITER as well as testing innovative reactor systems such as the Super-X divertor. MAST-U will have increased coil system and power supply capability. Therefore, to ensure operation of MAST-U within safe…
Preprint PublishedA. Sperduti M. Cecconello S. Conroy A. Snicker
A discrepancy between predicted and measured neutron rates on MAST using TRANSP/NUBEAM was observed. Further causes of this discrepancy are here studied by means of TRANSP/NUBEAM and ASCOT/BBNBI simulations. Gyro-Orbit simulations resulted in an approximately 20 % reduction of the fast ion density compare to the Guiding Center with TRANSP/NUBEAM…
Preprint PublishedM J Dunn T W Morgan J W Genuit T Loewenhoff A J Thornton K J Gibson the Magnum-PSI team
One of the issues faced by future fusion devices will be high target heat loads. Alternative divertors are a potential solution to the heat loads. They have been investigated in TCV and DIII-D, and will be investigated on MAST-U. To evaluate their effectiveness, accurate target heat flux and power balance measurements are required in these machines…
Preprint Published