Optimization of Steady-State Beam-Driven Tokamak Reactors

Mikkelsen, D. R.; Singer, Clifford E

doi:10.13182/fst83-a22816

Cited by 70 publications

(62 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Beam drive of current has been predicted by theory (see e.g. [6][7][8] and observed in many experiments (e.g., in TFTR [9,10], DIII-D [11,12], JET [13,14], JT-60U [15][16][17], for an overview see [18]). In most of these experiments the beam driven current was located on-axis, including those with N-NBI [16,17].…”

Section: Current Profile Modification By Off-axis Nbi On Asdex Upgradementioning

confidence: 99%

Interaction of energetic particles with large and small scale instabilities

Günter

Conway

Graca³

et al. 2007

Nucl. Fusion

124

View full text Add to dashboard Cite

Beyond a certain heating power, measured and predicted distributions of NBI driven currents deviate from each other even in the absence of MHD instabilities. The most reasonable explanation is a redistribution of fast NBI ions on a time scale smaller than the current redistribution time. The hypothesis of a redistribution of fast ions by background turbulence is discussed. Direct numerical simulation of fast test particles in a given field of electrostatic turbulence indicates that for reasonable parameters fast and thermal particle diffusion can indeed be similar. -High quality plasma edge density profiles on ASDEX Upgrade and the recent extension of the reflectometry system allow for a direct comparison of observed TAE eigenfunctions with theoretical ones as obtained with the linear, gyrokinetic, global stability code LIGKA. These comparisons support the hypothesis of TAE-frequency crossing the continuum at the plasma edge in ASDEX Upgrade H-mode discharges. -A new fast ion loss detector with 1 MHz time resolution allows frequency and phase resolved correlation between the observed losses and low frequency magnetic perturbations such as TAE modes and rotating magnetic islands.Whereas losses caused by TAE modes are known to be due to resonances in velocity space, by modelling of the particle drift orbits we were able to explain losses caused by magnetic islands as due to island formation and stochasticity in the drift orbits.

show abstract

Section: Current Profile Modification By Off-axis Nbi On Asdex Upgradementioning

confidence: 99%

Interaction of energetic particles with large and small scale instabilities

Günter

Conway

Graca³

et al. 2007

Nucl. Fusion

124

View full text Add to dashboard Cite

show abstract

“…The ICRF heating profile is taken from the TORIC4 results provided by the TSC/TRANSP simulations. The driven current profiles of NBCD and ECCD are calculated with the Mikkelsen and Singer's approximation [21] and with an empirical formula of the current drive efficiency, η ECCD =0.055(T e [keV]) 0.5 [10 20 A/Wm 2 ] [22], respectively.…”

Section: Simulation Tools Used In Scenario Modelingmentioning

confidence: 99%

Simulation of the hybrid and steady state advanced operating modes in ITER

et al. 2007

View full text Add to dashboard Cite

Abstract. Integrated simulations are done to establish a physics basis, in conjunction with present tokamak experiments, for the operating modes in ITER. Simulations of the hybrid mode are done using both fixed and free-boundary 1.5D transport evolution codes including CRONOS, ONETWO, TSC/TRANSP, TOPICS, and ASTRA. The hybrid operating mode is simulated using the GLF23 energy transport model. The injected powers are limited to the negative ion neutral beam (NBI), ion cyclotron (ICRF), and electron cyclotron (EC). Several plasma parameters and source parameters are specified for the hybrid cases to provide a comparison among the simulations. Simulations of the steady state operating mode are done with the same 1.5D transport evolution codes cited above. In these cases the energy transport model is more difficult to prescribe, so that energy confinement models will range from theory based to empirically based. The injected powers include the same sources for the hybrid with the possible addition of lower hybrid (LH). These simulations will be presented and compared with particular focus on code to code results when using the same energy transport model, and within the same code when using different energy transport models

show abstract

“…The factor J, discussed in Ref. [7], is given by J(x,y) = x 2 /{7 + x 3 + 2 x 2 } (for deuterium and Z = 2 giving y = 1), derived by fittings to j ∝ ∫dv v | | f with an analytical approximation for f, the distribution of beam ions slowing down by electron-ion collisions, with a cutoff at E c = 15T and x 2 = E/E c with beam energy E [6].…”

Section: Buildup Of the Currentmentioning

confidence: 99%

“…[8], giving I/P = 0.33J(T/nR)(1 -1/Z) = 0.06(T/nR)(1 -1/Z) evaluated at the maximum value of a quantity J playing the role of J(x,y) in Refs. [6] and [7] (both Cordey's J and J(x,y) have maxima at E = 80T [8]). …”

Section: Buildup Of the Currentmentioning

confidence: 99%

A Development Path for the Stabilized Spheromak

Fowler¹

2007

View full text Add to dashboard Cite

Optimization of Steady-State Beam-Driven Tokamak Reactors

Cited by 70 publications

References 30 publications

Interaction of energetic particles with large and small scale instabilities

Interaction of energetic particles with large and small scale instabilities

Simulation of the hybrid and steady state advanced operating modes in ITER

A Development Path for the Stabilized Spheromak

Contact Info

Product

Resources

About