O. Vallhagen I. Pusztai P. Helander S. L. Newton T. Fülöp
Pellet injection is used for fuelling and controlling discharges in tokamaks, and it is foreseen in ITER. During pellet injection, a movement of the ablated material towards the low- field side (or outward major radius direction) occurs because of the inhomogeneity of the magnetic field. Due to the complexity of the theoretical models, computer co…
PreprintH. Wu P. Shi F. Subba H. Sun M. Wischmeier R. Zanino the ASDEX Upgrade Team
The High Field High Density Region (HFSFD) has been experimentally observed in both divertor and limiter tokamak devices. In order to numerically reproduced the HFSHD region in the limiter tokamak device J-TEXT, we first performed SOLPS-ITER simulations on the J-TEXT limiter tokamak with the activation of drifts, which is associated with the HFSHD …
PreprintS. Saarelma J.W. Connor P. Bilkova P. Bohm A.R. Field L. Frassinetti R. Fridstrom A. Kirk JET Contributors*
The neutral ionisation model proposed by R J Groebner et al. (Phys Plasmas 9 2134 (2002)) to determine the plasma density profile in the H-mode pedestal, extended to include charge exchange processes in the pedestal stimulated by the ideas of Mahdavi et al. ((Phys Plasmas 10 3984 (2003)). The model is then tested a…
PreprintV.H. Hall-Chen F.I. Parra J.C. Hillesheim J. Ruiz Ruiz N.A. Crocker P. Shi H.S. Chu S.J. Freethy L.A. Kogan W.A. Peebles Q.T. Pratt T.L. Rhodes K. Ronald R. Scannell D.C. Speirs S. Storment J. Trisno
Doppler reflectometry, or the Doppler backscattering (DBS) diagnostic, enables the measurement of turbulent density fluctuations of intermediate length scales, typically $10 gtrsim k_perp rho_i gtrsim 1$; here $k_perp$ is the turbulence’s wavenumber and $rho_i$ is the ion gyroradius. The backscattered power is proportional to the power of the tur…
PreprintL. Howlett I. Cziegler S.J. Freethy H. Meyer
Spherical tokamaks are known to differ from conventional tokamaks in a number of physics areas, but our understanding is limited by a comparative lack of experimental data. A comprehensive study of the density dependence of the H-mode power threshold PLH on the Mega-Amp Spherical Tokamak (MAST) is presented, mapping out the low-density a…
PreprintH. J. Campbell F. Schoofs A. Reilly
Rare earth barium copper oxides (REBCO) are a particular class of cuprate high temperature superconductor. The favourable properties of REBCO coated conductor tapes (CCTs) and the well-established production methods have brought these tapes to the forefront of tokamak fusion research, showing a lot of promise for the development of powerful, high f…
PreprintA. I. Blair D. P. Hampshire
We investigate the in-field critical current density Jc(B) of superconducting-normal-superconducting (SNS) Josephson junctions (JJs) and polycrystalline superconducting systems with grain boundaries modeled as Josephson-type planar defects, both analytically and through computational time-dependent Ginzburg-Landau (TDGL) simulations in two and thre…
Preprint PublishedC. Cowley Bruce Lipschultz David Moulton Ben Dudson
As tokamak research moves to reactor conditions, the control of a stable, optimally-detached divertor plasma has become increasingly relevant. Simple predictions of such detachment control have been performed previously using the Detachment Location Sensitivity (DLS) model of detachment. In this study the DLS model is extended and combined with SOL…
Preprint PublishedV.H. Hall-Chen J. Damba F.I. Parra Q.T. Pratt C.A. Michael S. Peng T.L. Rhodes N.A. Crocker J.C. Hillesheim R. Hong S Ni W.A. Peebles C.E. Png J. Ruiz Ruiz
We use the beam model of Doppler backscattering (DBS), which was previously derived from beam tracing and the reciprocity theorem, to shed light on mismatch attenuation. This attenuation of the backscattered signal occurs when the wavevector of the probe beam’s electric field is not in the plane perpendicular to the magnetic field. Correcting for…
PreprintJ. Lovell M. L. Reinke A. R. Field B. A. Lomanowski the MAST Upgrade team
The MAST Upgrade tokamak has a suite of foil bolometers to measure the total radiated power from the plasma. Arrays of bolometers provide coverage of the main chamber and lower divertor radiation. Data is digitised and processe…
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