J W Berkery S A Sabbagh C Ham V Zamkovska J Butt J Riquezes M Tobin S Henderson L Kogan B Patel R Scannell E Trier B LeBlanc
Fusion power output from spherical tokamaks would benefit from increased confined plasma density, but there exists a limit on the density before confinement is lost and the plasma current is disrupted. This density limit has long been characterized by a simple, global Greenwald limit proportional to the plasma current and inversely proportional …
Preprint PurchaseD A Ryan R Martin N B Ayed L Kogan A Kirk the MAST Upgrade team
MAST Upgrade has just begun its second physics campaign. The set of magnetic probes used to diagnose the magnetic field and currents on MAST Upgrade are described, and their calibration procedures outlined including calculation of uncertainties. The arrays of installed instability diagnostics are described and the detection and diagnosis of a speci…
Preprint PublishedS.A. Sabbagh J.W. Berkery Y.S. Park J. Butt J.D. Riquezes J.G. Bak R.E. Bell L. Delgado-Aparicio C. Ham J. Hollocombe J.W. Lee J. Kim A. Kirk J. Ko W.H. Ko L. Kogan B.P. LeBlanc J.H. Lee A. Thornton S.W. Yoon
Disruption prediction and avoidance is a critical need for next-step tokamaks such as ITER. Disruption Event Characterization and Forecasting (DECAF) research fully automates analysis of tokamak data to determine chains of events that lead to disruptions and to forecast their evolution allowing sufficient time for mitigation or complete avoidance o…
Preprint PurchaseL. Kogan D. Ryan S. Gibson J. Berkery S. Sabbagh T. Farley P. Ryan K. Verhaugh B. Kool T.A. Wijkamp R. Scannell R. Sarwar C. Wade the MAST-U team
The MAST-U spherical tokamak has extensive capabilities to produce and explore strongly shaped plasmas and alternative divertor configurations, especially the Super-X. Robust and accurate reconstructions of plasma equilibria are the foundation of many physics analyses, as well as being important intershot for informing operation of the tokamak. …
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…
PreprintJW Berkery SA Sabbagh L Kogan S Gibson D Ryan V Zamkovska J Butt J Harrison S Henderson MAST-U team
The MAST-U fusion plasma research device, the upgrade to the Mega Amp Spherical Tokamak, has recently completed its first campaign of physics operation. MAST-U operated with Ohmic, or one or two neutral beams for heating, at 400-800 kA plasma current, in conventional or “SuperX” divertor configurations. Equilibrium reconstructions provide key p…
PreprintHyun-Tae Kim Francis Casson Hendrik Meyer Geof Cunningham Rory Scannell Lucy Kogan James Harrison Seong-Cheol Kim Jeong-Won Lee Jin-Woo Gwak Yong-Su Na Xavier Litaudon Gloria Falchetto3 MAST team
This paper describes the development of electromagnetic plasma burn-through model. Full circuit equations describing the currents in solenoid, poloidal field coil, and toroidally conducting passive structure have been integrated into the differential equation system of the plasma energy and particle balances in DYON. This enables consistent calcula…
Preprint PublishedA. SABBAGH J.W. BERKERY Y.S. PARK J.H. AHN Y. JIANG J.D. RIQUEZES J. BUTT J. BIALEK J.G. BAK M.J. CHOI S.H. HAHN J. KIM J. KO W.H. KO J.W. LEE J.H. LEE K.D. LEE L. TERZOLO S.W. YOON R.E. BELL M.D. BOYER K. ERICKSON B. LEBLANC M. PODESTA Z.R.WANG J. YOO C. HAM A. KIRK L. KOGAN D. RYAN A. THORNTON J. HOLLOCOMBE F.M. LEVINTON M.GALLANTE
Disruption prediction and avoidance is critical for ITER and reactor-scale tokamaks to maintain steady plasma operation and to avoid damage to device components. The present status and results from the disruption event characterization and forecasting (DECAF) research effort are shown. The DECAF paradigm is primarily physics-based and provides q…
PreprintJ. W. Berkery S. A. Sabbagh J. Bialek Y. Jiang C. Ham L. Kogan D. Ryan A. Thornton G. Xia D. Battaglia Z. Wang A. Piccione Y. Andreopoulos L. Guazzotto S. Gibson Y. Q. Liu
In preparation for high fusion plasma performance operation of the newly operating spherical tokamak MAST-U, the equilibrium and stability properties of plasmas in the MAST database, as well as projections for MAST-U, are explored. The disruption event characterization and forecasting (DECAF) code is utilized to map disruptions in MAST, particul…
PreprintJ. 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…
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