Numerical validation of the electromagnetic gyrokinetic code NEMORB on global axisymmetric modes

Biancalani, A.; Bottino, A.; Lauber, P.; Zarzoso, D.

doi:10.1088/0029-5515/54/10/104004

Cited by 31 publications

(72 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resonant damping rate is sensitive to and significantly enhanced by k r ρ i , where k r is the radial wave number. When only the 2-nd resonance is taken into account, a recent NEMORB simulation [8] performed a good agreement with the analytical result to the 2-nd FOW effects for about q < 3.5 [2]. It was shown that for q > 3.5, the discrepancy between the theoretical result with 2nd harmonics and the TEMPEST simulation data becomes remarkable [6].…”

supporting

confidence: 56%

“…Good agreement is found between the analytical results and the exact numerical solution of Eq. (8). Fig.…”

mentioning

confidence: 99%

“…On the other hand, due to the Landau damping, the FOW 3 term affects the damping rate dramatically. According to the dispersion relation (8), numerical result can be easily evaluated to explore the effects of torodial rotation on the GAM Landau damping.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Energetic particle driven geodesic acoustic mode in a toroidally rotating tokamak plasma

Ren

2016

Nucl. Fusion

View full text Add to dashboard Cite

The Landau damping of geodesic acoustic mode (GAM) in a torodial rotating tokamak plasma is analytically investigated by taking into account the finite-orbit-width (FOW) resonance effect to the 3rd order. The analytical result is shown to agree well with the numerical solution. The dependence of the damping rate on the toroidal Mach number M relies on krρi. For sufficiently small krρi, the damping rate monotonically decreases with M . For relatively large krρi, the damping rate increases with M until approaching the maximum and then decreases with M .In the kinetic framework, keeping terms to the 1st order finite-Larmor-radius (FLR) effect, which represents the leading order polarization, and the 1st order finiteorbit-width (FOW) effect of passing particles δ i ∼ qρ i , where q is the safety factor of tokamaks and ρ i is the ion gyroradius, the dispersion relation of geodesic acoustic mode (GAM) [1] is derived. The classical Landau damping rate of GAM is found to be ∝ e −q 2 Ω 2 and independent of δ i , where Ω is the GAM frequency normalized by R/v T i with major radius R and ions thermal velocity v T i . Later, some theoretical analysis[2-4], numerical evaluation [5], and simulation [6,7] all indicate that the high-order FOW effect plays a key role in the collisionless damping of GAM, specifically in the large q region. The resonant damping rate is sensitive to and significantly enhanced by k r ρ i , where k r is the radial wave number. When only the 2-nd resonance is taken into account, a recent NEMORB simulation [8] performed a good agreement with the analytical result to the 2-nd FOW effects for about q < 3.5 [2]. It was shown that for q > 3.5, the discrepancy between the theoretical result with 2nd harmonics and the TEMPEST simulation data becomes remarkable [6]. That means higher-order resonance should be considered. The numerical evaluation performed by Gao et al. [5] shows that the damping rate with 3-rd resonance and the one with 4-th resonance have only slight discrepancy when q is about greater than 7. Meanwhile, Xu et al. numerically found that the damping rate with 4-th order resonance is almost the same as the rate with 10-th resonance [6].In a recent work[9], Guo and co-authors investigated the collisionless damping rate of GAM by taking into account the toroidal rotation. They numerically evaluated the influence of toroidal Mach number on the Landau damping rate by considering from 2nd to 5th FOW resonance effect, respectively. Similar to the case without toroidal rotation [5,6,10], they found that the damping rate was significantly enhanced by 3rd resonance and the damping rate with 3rd resonance and the one with 4th * Electronic address: hjren@ustc.edu.cn or 5th resonance are almost the same with each other. In this Letter, theoretical investigation on the collisionless damping of GAM in a toroidally rotating tokamak plasma is performed. We derive the analytical expression for the Landau damping rate by considering the FOW resonance effect to the 3rd order. Good agreement is found between our...

show abstract

supporting

confidence: 56%

“…Good agreement is found between the analytical results and the exact numerical solution of Eq. (8). Fig.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Energetic particle driven geodesic acoustic mode in a toroidally rotating tokamak plasma

Ren

2016

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…The case n EP /n th = 0 corresponds to the standard GAM. It is well-known that for the standard GAM the ion Landau damping rate strongly depends on FLR/FOW effects via k ⊥ ρ i and the safety factor q [18] as was recently observed in Nemorb simulations [17]. Therefore, one might expect that the disagreement observed for n EP /n th = [0.05, 0.1] is also due to FLR/FOW effects.…”

Section: Comparison Of Theoretical Dispersion Relation With Gyrokinetmentioning

confidence: 69%

“…Let us recall that Nemorb has already proved its capability to simulate EGAMs with adiabatic electrons. First benchmarks against the electrostatic simulations performed with the gyrokinetic code GYSELA [5] have been successfully made and published very recently [17]. The aim of this section is twofold.…”

Section: Comparison Of Theoretical Dispersion Relation With Gyrokinetmentioning

confidence: 99%

Analytic dispersion relation of energetic particle driven geodesic acoustic modes and simulations with NEMORB

et al. 2014

Self Cite

View full text Add to dashboard Cite

Abstract. Recent progress regarding the excitation of energetic-particle driven geodesic acoustic modes (EGAMs) in particle-in-cell simulations is presented in this paper. The exact dispersion relation with adiabatic electrons is derived and solved. The origin of the so-called EGAM is briefly analysed and we show that its nature changes, at least, with the safety factor. A simple expression for the GAM frequency modified in the presence of a small concentration of energetic particles is given in the fluid limit. We show that gyrokinetic simulations with Nemorb in the presence of adiabatic electrons are able to reproduce the analytic predictions. Also, different energy channels are analysed by means of dedicated energy diagnostics characterizing the wave-particle interaction. Finite Larmor radius and finite orbit width effects are studied regarding the excitation of geodesic acoustic modes, showing that these effects are likely to be negligible for sufficiently high concentration of energetic particles, but significant when approaching the threshold of excitation.

show abstract

A 5D gyrokinetic full-f global semi-Lagrangian code for flux-driven ion turbulence simulations

Grandgirard

Abiteboul

Bigot

et al. 2016

Computer Physics Communications

Self Cite

101

115

View full text Add to dashboard Cite

This paper addresses non-linear gyrokinetic simulations of ion temperature gradient (ITG) turbulence in tokamak plasmas. The electrostatic Gysela code is one of the few international 5D gyrokinetic codes able to perform global, full-f and flux-driven simulations. Its has also the numerical originality of being based on a semi-Lagrangian (SL) method. This reference paper for the Gysela code presents a complete description of its multi-ion species version including: (i) numerical scheme, (ii) high level of parallelism up to 500k cores and (iii) conservation law properties.

show abstract

Numerical validation of the electromagnetic gyrokinetic code NEMORB on global axisymmetric modes

Cited by 31 publications

References 37 publications

Energetic particle driven geodesic acoustic mode in a toroidally rotating tokamak plasma

Energetic particle driven geodesic acoustic mode in a toroidally rotating tokamak plasma

Analytic dispersion relation of energetic particle driven geodesic acoustic modes and simulations with NEMORB

A 5D gyrokinetic full-f global semi-Lagrangian code for flux-driven ion turbulence simulations

Contact Info

Product

Resources

About