Comparisons of predicted plasma performance in ITER H-mode plasmas with various mixes of external heating

Budny, R.

doi:10.1088/0029-5515/49/8/085008

Cited by 57 publications

(72 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[13] is applicable to the pedestal of ITER where the electron mean-free-path λmfp is much longer than the field line connection length qR, i.e., the electrons are in the collisionless regime, and the electron thermal conductivity in the stochastic magnetic field becomes χe = (λmfp/qR) (ρe/LT) 2 ve 2 /(νei q) Such high values of χe should overwhelm the heat transport due to other microinstabilities. The value of χe obtained from transport analysis [10] of the ITER pedestal region, self-consistent with the heat flux and the temperature profile, is below 3x10 5 cm -3 , two orders of magnitude lower than the above values. This simply means that such a steep temperature profile will not hold -the pedestal will be broadened by the unstable microtearing modes.…”

supporting

confidence: 68%

See 1 more Smart Citation

Microtearing Instability In The ITER Pedestal

Wong¹,

Mikkelsen²,

Rewoldt³

et al. 2010

View full text Add to dashboard Cite

supporting

confidence: 68%

“…A recently published simulated ITER H-mode plasma [10] 2006P07 was chosen for our investigation. It has approximately 400 MW DT fusion power at t=300s.…”

mentioning

confidence: 99%

Microtearing Instability In The ITER Pedestal

Wong¹,

Mikkelsen²,

Rewoldt³

et al. 2010

View full text Add to dashboard Cite

“…However, in reactors with high NBI power at high beam energy, the torque is expected to be small. The central toroidal rotation velocity for ITER H-mode plasmas with NBI power of 34 MW, was predicted to be in the range of 10-170 km/s [4]. This is lower than currently observed at JET for the same Prandtl number (ratio between momentum and ion heat diffusivity) and with NBI power less than 20 MW [5].…”

Section: -Introductionmentioning

confidence: 70%

“…2) than in the newer ELMy pulses (figs. [3][4][5], that may lead to a higher pedestal and core rotation.…”

Section: -Discussion and Conclusionmentioning

confidence: 99%

JET intrinsic rotation studies in plasmas with a high normalized beta and varying toroidal field ripple

Nave

Eriksson

Giroud

et al. 2012

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

Understanding the origin of rotation in Ion Cyclotron Resonance Frequency (ICRF) heated plasmas is important for predictions for burning plasmas sustained by alpha particles, being characterized by a large population of fast ions and no external momentum input. The angular velocity of the plasma column has been measured in JET H-mode plasmas with pure ICRF heating for both the standard low toroidal magnetic ripple configuration, of about ~ 0.08% and, for increased ripple values up to 1.5 % [1]. These new JET rotation data were compared with the multi-machine scaling of ref. [2] for the Alfven-Mach number and with the scaling for the velocity change from L-mode into H-mode. The JET data do not fit well any of these scalings that were derived for plasmas that are co-rotating with respect to the plasma-current.With the standard low ripple configuration, JET plasmas with large ICRF heating power and normalized beta, βN ≈1.3, have a very small co-current rotation, with Alfven-Mach numbers significantly below those given by the rotation scaling of ref. [2]. In some cases the plasmas are actually counter-rotating. No significant difference between the H-mode and L-mode rotation is observed. Typically the H-mode velocities near the edge are lower than in Lmodes. With ripple values larger than the standard JET value, between 1% and 1.5%, H-mode plasmas were obtained where both the edge and the core counter rotated. I -IntroductionIntrinsic rotation can play a key role in the performance of future tokamak power plants where the momentum input will be small [3]. In present day tokamak experiments, rotation is mostly driven by the torque coming from the neutral beam injection (NBI). However, in reactors with high NBI power at high beam energy, the torque is expected to be small. The central toroidal rotation velocity for ITER H-mode plasmas with NBI power of 34 MW, was predicted to be in the range of 10-170 km/s [4]. This is lower than currently observed at JET for the same Prandtl number (ratio between momentum and ion heat diffusivity) and with NBI power less than 20 MW [5]. It is important to note that ITER simulations depend on options of momentum transport whose theory is still evolving. For instance, the ITER simulations of ref.[4] do not include any contribution from a momentum pinch which is found to exist in JET NBI discharges [6,7] and other tokamaks [8,9]. This inward pinch will modify the rotation profile in ITER, in particular the peaking of the rotation profile will increase. Understanding of momentum transport is crucial in order to reliably model rotation profiles in ITER and other future devices, however, this is not the scope of this paper. A good overview of momentum transport theory, covering also aspects like residual stress and up-down asymmetry that may affect significantly the rotation profile in ITER, is given in reference [10].As the NBI driven rotation in future machines is presumed to be small, the intrinsic plasma rotation, which occurs in the absence of momentum sources such as NBI, has...

show abstract

“…The PTRANSP code [5][6][7][8] is used to generate predictions of ITER plasmas for use as benchmarking cases. The cases are listed in Table I.…”

Section: Benchmark Casesmentioning

confidence: 99%

Benchmarking ICRF Full-wave Solvers for ITER

2011

View full text Add to dashboard Cite

Benchmarking of full-wave solvers for ICRF simulations is performed using plasma profiles and equilibria obtained from integrated self-consistent modeling predictions of four ITER plasmas. One is for a high performance baseline (5.3 T, 15 MA) DT H-mode. The others are for half-field, half-current plasmas of interest for the pre-activation phase with bulk plasma ion species being either hydrogen or He 4 . The predicted profiles are used by six full-wave solver groups to simulate the ICRF electromagnetic fields and heating, and by three of these groups to simulate the current-drive.Approximate agreement is achieved for the predicted heating power for the DT and He 4 cases. Factor of two disagreements are found for the cases with second harmonic He 3 heating in bulk H cases. Approximate agreement is achieved simulating the ICRF current drive.

show abstract

Comparisons of predicted plasma performance in ITER H-mode plasmas with various mixes of external heating

Cited by 57 publications

References 46 publications

Microtearing Instability In The ITER Pedestal

Microtearing Instability In The ITER Pedestal

JET intrinsic rotation studies in plasmas with a high normalized beta and varying toroidal field ripple

Benchmarking ICRF Full-wave Solvers for ITER

Contact Info

Product

Resources

About