Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where J. Bao is active.

Publication


Featured researches published by J. Bao.


Physics of Plasmas | 2015

Verification of nonlinear particle simulation of radio frequency waves in tokamak

Animesh Kuley; Zhihong Lin; J. Bao; X. S. Wei; Y. Xiao; W. Zhang; G. Y. Sun; N. J. Fisch

Nonlinear simulation model for radio frequency waves in fusion plasmas has been developed and verified using fully kinetic ion and drift kinetic electron. Ion cyclotron motion in the toroidal geometry is implemented using Boris push in the Boozer coordinates. Linear dispersion relation and nonlinear particle trapping are verified for the lower hybrid wave and ion Bernstein wave (IBW). Parametric decay instability is observed where a large amplitude pump wave decays into an IBW sideband and an ion cyclotron quasimode (ICQM). The ICQM induces an ion perpendicular heating, with a heating rate proportional to the pump wave intensity.


Physics of Plasmas | 2016

Nonlinear electromagnetic formulation for particle-in-cell simulation of lower hybrid waves in toroidal geometry

J. Bao; Zhihong Lin; Animesh Kuley; Zhixuan Wang

An electromagnetic particle simulation model has been formulated and verified for nonlinear processes of lower hybrid (LH) waves in fusion plasmas. Electron dynamics are described by the drift kinetic equation using either kinetic momentum or canonical momentum. Ion dynamics are treated as the fluid system or by the Vlasov equation. Compressible magnetic perturbation is retained to simulate both the fast and slow LH waves. Numerical properties are greatly improved by using the electron continuity equation to enforce the consistency between electrostatic potential and vector potential, and by using the importance sampling scheme. The simulation model has been implemented in the gyrokinetic toroidal code (GTC), and verified for the dispersion relation and nonlinear particle trapping of the electromagnetic LH waves.


Nuclear Fusion | 2016

Electromagnetic particle simulation of the effect of toroidicity on linear mode conversion and absorption of lower hybrid waves

J. Bao; Zhihong Lin; Animesh Kuley; Zhixuan Wang

Effects of toroidicity on linear mode conversion and absorption of lower hybrid (LH) waves in fusion plasmas have been studied using electromagnetic particle simulation. The simulation confirms that the toroidicity induces an upshift of parallel refractive index when LH waves propagate from the tokamak edge toward the core, which affects the radial position for the mode conversion between slow and fast LH waves. Furthermore, moving LH antenna launch position from low field side toward high field side leads to a larger upshift of the parallel refractive index, which helps the slow LH wave penetration into the tokamak core. The broadening of the poloidal spectrum of the wave-packet due to wave diffraction is also verified in the simulation. Both the upshift and broadening effects of the parallel spectrum of the wave-packet modify the parallel phase velocity and thus the linear absorption of LH waves by electron Landau resonance.


Physics of Plasmas | 2017

Gyrokinetic particle simulations of the effects of compressional magnetic perturbations on drift-Alfvenic instabilities in tokamaks

Ge Dong; J. Bao; A. Bhattacharjee; Alain J. Brizard; Zhihong Lin; Peter Porazik

The compressional component of magnetic perturbation δ B ∥ can play an important role in drift-Alfvenic instabilities in tokamaks, especially as the plasma β increases (β is the ratio of kinetic pressure to magnetic pressure). In this work, we have formulated a gyrokinetic particle simulation model incorporating δ B ∥ , and verified the model in kinetic Alfven wave simulations using the Gyrokinetic Toroidal Code in slab geometry. Simulations of drift-Alfvenic instabilities in tokamak geometry shows that the kinetic ballooning mode (KBM) growth rate decreases more than 20% when δ B ∥ is neglected for β e = 0.02 , and that δ B ∥ has stabilizing effects on the ion temperature gradient instability, but negligible effects on the collisionless trapped electron mode. The KBM growth rate decreases about 15% when equilibrium current is neglected.


Physics of Plasmas | 2017

A conservative scheme of drift kinetic electrons for gyrokinetic simulation of kinetic-MHD processes in toroidal plasmas

J. Bao; D. Liu; Zhihong Lin

A conservative scheme of drift kinetic electrons for gyrokinetic simulations of kinetic-magnetohydrodynamic processes in toroidal plasmas has been formulated and verified. Both vector potential and electron perturbed distribution function are decomposed into adiabatic part with analytic solution and non-adiabatic part solved numerically. The adiabatic parallel electric field is solved directly from the electron adiabatic response, resulting in a high degree of accuracy. The consistency between electrostatic potential and parallel vector potential is enforced by using the electron continuity equation. Since particles are only used to calculate the non-adiabatic response, which is used to calculate the non-adiabatic vector potential through Ohms law, the conservative scheme minimizes the electron particle noise and mitigates the cancellation problem. Linear dispersion relations of the kinetic Alfven wave and the collisionless tearing mode in cylindrical geometry have been verified in gyrokinetic toroidal c...


Physics of Plasmas | 2018

A conservative scheme for electromagnetic simulation of magnetized plasmas with kinetic electrons

J. Bao; Zhihong Lin; Zhixin Lu

A conservative scheme has been formulated and verified for gyrokinetic particle simulations of electromagnetic waves and instabilities in magnetized plasmas. An electron continuity equation derived from the drift kinetic equation is used to time advance the electron density perturbation by using the perturbed mechanical flow calculated from the parallel vector potential, and the parallel vector potential is solved by using the perturbed canonical flow from the perturbed distribution function. In gyrokinetic particle simulations using this new scheme, the shear Alfven wave dispersion relation in the shearless slab and continuum damping in the sheared cylinder have been recovered. The new scheme overcomes the stringent requirement in the conventional perturbative simulation method that perpendicular grid size needs to be as small as electron collisionless skin depth even for the long wavelength Alfven waves. The new scheme also avoids the problem in the conventional method that an unphysically large paralle...


RADIO FREQUENCY POWER IN PLASMAS: Proceedings of the 21st Topical Conference | 2015

Global particle simulation of lower hybrid wave propagation and mode conversion in tokamaks

J. Bao; Zhihong Lin; Animesh Kuley

Particle-in-cell simulation of lower hybrid (LH) waves in core plasmas is presented with a realistic electron-to-ion mass ratio in toroidal geometry. Due to the fact that LH waves mainly interact with electrons to drive the current, ion dynamic is described by cold fluid equations for simplicity, while electron dynamic is described by drift kinetic equations. This model could be considered as a new method to study LH waves in tokamak plasmas, which has advantages in nonlinear simulations. The mode conversion between slow and fast waves is observed in the simulation when the accessibility condition is not satisfied, which is consistent with the theory. The poloidal spectrum upshift and broadening effects are observed during LH wave propagation in the toroidal geometry.


RADIO FREQUENCY POWER IN PLASMAS: Proceedings of the 21st Topical Conference | 2015

Nonlinear particle simulation of ion cyclotron waves in toroidal geometry

Animesh Kuley; J. Bao; Zhihong Lin; X. S. Wei; Y. Xiao

Global particle simulation model has been developed in this work to provide a first-principles tool for studying the nonlinear interactions of radio frequency (RF) waves with plasmas in tokamak. In this model, ions are considered as fully kinetic particles using the Vlasov equation and electrons are treated as guiding centers using the drift kinetic equation with realistic electron-to-ion mass ratio. Boris push scheme for the ion motion has been developed in the toroidal geometry using magnetic coordinates and successfully verified for the ion cyclotron and ion Bernstein waves in global gyrokinetic toroidal code (GTC). The nonlinear simulation capability is applied to study the parametric decay instability of a pump wave into an ion Bernstein wave side band and a low frequency ion cyclotron quasi mode.


arXiv: Plasma Physics | 2018

Nonlinear Saturation of Kinetic Ballooning Modes by Zonal fields in Toroidal Plasmas

Ge Dong; J. Bao; A. Bhattacharjee; Zhihong Lin


arXiv: Plasma Physics | 2017

Global particle in cell simulation of fusion plasma in cylindrical coordinates

Animesh Kuley; J. Bao; Zhihong Lin; G. Y. Sun

Collaboration


Dive into the J. Bao's collaboration.

Top Co-Authors

Avatar

Zhihong Lin

University of California

View shared research outputs
Top Co-Authors

Avatar

Animesh Kuley

Indian Institute of Technology Delhi

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ge Dong

Princeton Plasma Physics Laboratory

View shared research outputs
Top Co-Authors

Avatar

Zhixuan Wang

University of California

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge