A5000584325- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Physics of Superconductivity and Magnetism
- Computational Fluid Dynamics and Aerodynamics
- Atomic and Subatomic Physics Research
- Geomagnetism and Paleomagnetism Studies
- Nuclear Physics and Applications
- Fluid Dynamics and Turbulent Flows
- Gas Dynamics and Kinetic Theory
- Power System Optimization and Stability
- Advanced Numerical Methods in Computational Mathematics
- Particle Detector Development and Performance
- Plasma and Flow Control in Aerodynamics
- earthquake and tectonic studies
- Quantum chaos and dynamical systems
- Numerical methods for differential equations
- Advanced Data Storage Technologies
- Astro and Planetary Science
Princeton Plasma Physics Laboratory
2015-2024
Max Planck Institute for Plasma Physics
1989-2021
Culham Science Centre
2021
ITER
2020-2021
Princeton University
2005-2020
Dutch Institute for Fundamental Energy Research
2020
University of Wisconsin–Madison
2020
Pohang University of Science and Technology
2016
Ulsan National Institute of Science and Technology
2016
Korea Institute of Fusion Energy
2016
Progress in the area of MHD stability and disruptions, since publication 1999 ITER Physics Basis document (1999 Nucl. Fusion 39 2137–2664), is reviewed. Recent theoretical experimental research has made important advances both understanding control tokamak plasmas. Sawteeth are anticipated baseline ELMy H-mode scenario, but tools exist to avoid or them through localized current drive fast ion generation. Active other instabilities will most likely be also required ITER. Extrapolation from...
Abstract The objectives of NSTX-U research are to reinforce the advantages STs while addressing challenges. To extend confinement physics low- A , high beta plasmas lower collisionality levels, understanding transport mechanisms that set performance and pedestal profiles is being advanced through gyrokinetic simulations, reduced model development, comparison NSTX experiment, as well improved simulation RF heating. develop stable non-inductive scenarios needed for steady-state operation,...
The National Spherical Torus Experiment (NSTX) is being built at Princeton Plasma Physics Laboratory to test the fusion physics principles for spherical torus concept MA level. NSTX nominal plasma parameters are R0 = 85 cm, a 67 R/a ⩾ 1.26, Bt 3 kG, Ip 1 MA, q95 14, elongation κ ⩽ 2.2, triangularity δ 0.5 and pulse length of up 5 s. heating/current drive tools high harmonic fast wave (6 MW, s), neutral beam injection (5 80 keV, s) coaxial helicity injection. Theoretical calculations predict...
Global hybrid simulations of energetic particle effects on the n=1 internal kink mode have been carried out for tokamaks. For International Thermonuclear Experimental Reactor (ITER) [ITER Physics Basis Editors et al., Nucl. Fusion 39, 2137 (1999)], it is shown that alpha are stabilizing mode. However, elongation ITER reduces stabilization significantly. Nonlinear precessional drift fishbone instability circular tokamak plasmas show saturates due to flattening distribution function near...
A novel method for creating the spheromak configuration has been proposed and verified experimentally. The scheme is based on a transfer of poloidal toroidal magnetic fluxes into plasma from "flux core." We present first experimental verification this quasistatic (${\ensuremath{\tau}}_{\mathrm{Alfv}\stackrel{\ifmmode\acute\else\textasciiacute\fi{}}{\mathrm{e}}\mathrm{n}}\ensuremath{\ll}{\ensuremath{\tau}}_{\mathrm{form}}<{\ensuremath{\tau}}_{\mathrm{diff}}$) formation scheme, which...
The M3D-C1 (Breslau et al 2009 Phys. Plasmas 16 092503) code is designed for performing three-dimensional nonlinear magnetohydrodynamics (MHD) calculations of a tokamak plasma that span the timescales associated with ideal and resistive stability as well parallel perpendicular transport. This requires scalable fully implicit time advance where step not limited by Courant condition based on MHD wave velocities or flow but chosen instead to accurately efficiently resolve physics. In order...
We demonstrate that in a 3D resistive magnetohydrodynamic simulation, for some parameters it is possible to form stationary state tokamak where saturated interchange mode the center of discharge drives near helical flow pattern acts nonlinearly sustain configuration by adjusting central loop voltage through dynamo action. This could explain physical mechanism maintaining nonsawtoothing "hybrid" discharges, often referred as "flux pumping."
The Tokamak Simulation Code (TSC) has been used to model the time dependence of several Ohmic discharges in TFTR experiment. semi-empirical thermal conductivity and sawtooth TSC have refined so that good agreement between simulation experiment is obtained electron ion temperature profiles current for entire duration discharges. Neoclassical resistivity gives with measured surface voltage rate poloidal flux consumption
The ideal magnetohydrodynamic (MHD) stability limits of low aspect ratio tokamak plasmas are computed numerically for with a range cylindrical safety factors q*, normalized plasma pressures beta , elongations kappa and central q(0). Four distinct regimes optimized, namely: (a) low-q* q(0)=1.1 without stabilizing wall, (b) no wall 1.1<q(0)<2, (c) high- high bootstrap fraction at moderate requiring edge current drive (d) very to but little external drive. A stable equilibrium is found an A=1.4...
Recent experiments in the Current Drive Experiment-Upgrade (CDX-U) provide a first-ever test of large area liquid lithium surfaces as tokamak first wall to gain engineering experience with metal and investigate whether very low recycling plasma regimes can be accessed walls. The CDX-U is compact (R = 34 cm, 22 Btoroidal 2 kG, IP 100 kA, Te(0)∼ eV, ne(0) ∼ 5 × 1019 m−3) spherical torus at Princeton Plasma Physics Laboratory. A toroidal pool limiter an 2000 cm2 (half total limiting surface)...
Indentation of a tokamak plasma on its inner-major-radius side is shown to be strongly beneficial for achieving high-$\ensuremath{\beta}$ stability against ballooning modes. With use set reasonable equilibrium profiles, it found that moderate indentation provides accessibility the second region stability. Ohmic configurations which exhibit have not yet been found.
Research on the National Spherical Torus Experiment, NSTX, targets physics understanding needed for extrapolation to a steady-state ST Fusion Nuclear Science Facility, pilot plant, or DEMO. The unique operational space is leveraged test theories next-step tokamak operation, including ITER. Present research also examines implications coming device upgrade, NSTX-U. An energy confinement time, τE, scaling unified varied wall conditions exhibits strong improvement of BTτE with decreased electron...
The National Spherical Torus Experiment (NSTX) has undergone a major upgrade, and the NSTX Upgrade (NSTX-U) Project was completed in summer of 2015.NSTX-U first plasma subsequently achieved, diagnostic control systems have been commissioned, H-mode accessed, magnetic error fields identified mitigated, physics research campaign carried out.During ten run weeks operation, NSTX-U surpassed record pulse-durations toroidal (TF), high-performance ~1 MA plasmas comparable to best sustained near...
Relativistic electron (RE) beams at high current density (low safety factor, qa) yet very low free-electron accessed with D2 secondary injection in the DIII-D and JET tokamak are found to exhibit large-scale MHD instabilities that benignly terminate RE beam. In JET, this technique has enabled termination of MA-level currents without measurable first-wall heating. This scenario thus offers an unexpected alternate pathway achieve mitigation collisional dissipation. Benign is explained by two...
AbstractThe mission of the National Spherical Torus Experiment (NSTX) is to prove principles spherical torus physics by producing high-βt plasmas that are noninductively sustained and whose current profiles in steady state. The NSTX will be one first ultralow-aspect-ratio tori (R/a ≤ 1.3) operate at high power (Pinput up 11 MW) produce (25 40%), low-collisionality, high-bootstrap-fraction (≤70%) discharges. Both radio-frequency neutral beam heating drive employed. Built into sufficient...
A dynamic computational model of lower hybrid current drive in the presence an electric field is described and some results are given. Details geometry, plasma profiles circuit equations treated carefully. Two dimensional velocity space effects approximated a one Fokker-Planck treatment. The unable to approximate experimental cases characterized by low density, current, high aspect ratio launched spectrum at phase relative thermal velocity. In other cases, qualitative agreement with...
Plasma shape and position control in elongated tokamaks is analysed, using the TSC code. The paper presents a new algorithm which allows evolution of discharge to be entirely preprogrammed. computes poloidal field coil voltages as functions time, magnetic measurements made close vessel wall. No preprogrammed current wave forms are required. By simulating start-up phase typical TCV tokamak discharges, it shown that actual follows closely one. X-points can specified at arbitrary positions....
Growth rates of edge localized modes for various benchmark equilibria, including a diverted equilibrium, are calculated using the nonideal fluid code M3D-C1. by M3D-C1 in ideal limit found to agree with those magnetohydrodynamics codes. The effects nonuniform density and resistivity profiles explored, as well sensitivity growth position vacuum-plasma interface. equilibrium be particularly sensitive moving this interface inward from separatrix, but less extending plasma region beyond...
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