A5016382196- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Radiation Detection and Scintillator Technologies
- Astro and Planetary Science
- Silicon and Solar Cell Technologies
- Dust and Plasma Wave Phenomena
- Particle Detector Development and Performance
- Gas Dynamics and Kinetic Theory
- Astrophysics and Star Formation Studies
- Solid-state spectroscopy and crystallography
- High-pressure geophysics and materials
- Plasma Diagnostics and Applications
- Cold Fusion and Nuclear Reactions
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
Institute of Plasma Physics
2013-2022
Chinese Academy of Sciences
2008-2021
Lawrence Livermore National Laboratory
2020
University of Science and Technology of China
2018
Hefei Institutes of Physical Science
2008
Fast ion losses in the presence of resonant magnetic perturbations (RMPs) on EAST tokamak have been simulated by using Monte Carlo orbit-following code GYCAVA (Xu et al 2019 Comput. Phys. Comm. 244 40). ions produced co-current tangential neutral beam injection (NBI) were considered. The initial distribution NBI fast was numerically computed TGCO and n = 1 vacuum response RMP fields MHD MARS-F (Liu 2000 Plasmas 7 3681). It is found that increase almost linearly with coil current. Poincaré...
The electrostatic gyrokinetic nonlinear turbulence code NLT, which is based on a numerical Lie-transform perturbation method, developed. For improving the computational efficiency and avoiding instabilities, field-aligned coordinates Fourier filter are adopted in NLT code. Nonlinear tests of ion temperature gradient driven with adiabatic electrons performed for verifying by comparing other codes. time evolution heat diffusivity relation between compared tests. Good agreements achieved from...
Linear gyrokinetic theory based on the Lie-transform perturbation method is presented in terms of exact canonical variables. In linear drift approximation, it shown that gyrocenter equations motion variables are equivalent to usual guiding-center motion. A numerical code developed advance with arbitrary perturbations. It found a static magnetic island tokamak has little effect trapped particle orbits due conservation longitudinal invariant; and induces structure passing fact invariant for...
The effects of resonant magnetic perturbations (RMPs) and the drift on loss redistribution passing ions are investigated numerically by upgrade version orbit following code GYCAVA. island structures ion orbits induced RMPs consistent with given toroidal poloidal mode numbers in simulations. energetic thermal without studied compared each other. near edge is due to drift. extra related structure stochasticity overlap islands. n = 1 larger than that 4 for same perturbation amplitude parameter,...
Based on the semi-Lagrangian method, a δf drift kinetic continuum code incorporating magnetic flux coordinate was developed and applied to investigate geodesic acoustic mode (GAM) oscillation in multi-ion plasma system. This work proves clearly that effective ion mass number affects GAM In this simulation, frequency damping rate are seen vary with proportion of impurity ions. The numerical result is consistent theoretical prediction terms both rate.
Hamiltonian correction method is proposed to improve the variable time-step fourth-order Runge–Kutta methods in computing guiding-center orbits a tokamak. It found that new can significantly computation efficiency of conventional simulation long-time behavior orbits.
Abstract The computation efficiency of high dimensional (3D and 4D) B-spline interpolation, constructed by classical tensor product method, is improved greatly precomputing the function. This due to character NLT code, i.e. only linearised characteristics are needed so that unperturbed orbit as well values function at interpolation points can be precomputed beginning simulation. By integrating this fixed point algorithm into gyro-kinetic Vlasov equation solved directly without operator...
A numerical code based on the I-transform approach is developed to solve nonlinear Vlasov equation and carry out transport analysis. The results given by agree with conservative semi-Lagrangian in Landau damping case bump-on-tail instability case. diffusivities induced random fields quasilinear are also successfully demonstrated using new approach. It found that one-dimensional Langmuir turbulence cannot be well-described a simple diffusion model, due strong particle trapping at stage.
A simple analytical model is proposed to analyze the effects of ion orbit loss on edge radial electric field in a tokamak with limiter configuration. The analytically predicted consistent H-mode experiments, including width, magnitude, and well-like shape. This provides an explanation pedestal structure. Scaling width based this proposed.
A guiding center orbit following code, which incorporates a set of non-singular coordinates for integration, was developed and applied to investigate the alpha particle heating in an ITER-like tokamak with internal transport barrier. It is found that relatively large q (safety factor) value can significantly broaden profile comparison local approximation; this broadening due finite width effects; when much smaller than scale length source profile, agrees otherwise, be broadened. also...
Field-aligned coordinates have been implemented in the gyrokinetic semi-Lagrangian code NLT, Ye et al (2016 J. Comput. Phys. 316 180), to improve computational efficiency for numerical simulations of tokamak turbulence and transport. 4D B-spline interpolation field-aligned is applied solve Vlasov equation. A fast iterative algorithm proposed efficiently solving quasi-neutrality pseudo transform method used integration gyro-average operator perturbations with a high toroidal mode number. The...
The effects of resonant magnetic perturbations (RMPs) on tangential neutral beam heating in the EAST tokamak are studied numerically. RMPs with linear resistive magnetohydrodynamics response used modeling. A variety representing configurations RMP coil currents examined, and their injection (NBI) efficiency compared, order to find a parameter window where deleterious NBI minimized. It is found that internal redistribution fast ions by induces local accumulation ions, resulting higher ion...
Abstract The fast ions and electrons generated by neutral beam injection (NBI) can induce charge separation, resulting in radial electric fields. Employing beamlet of small cross-section may effectively generate field, adjusting parameters allows active control over their distribution. A new NBI geometry system has been developed the NEOE code to explore potential for vertical beamlets future fusion reactor scenarios. Both high-field side low-field injections establish In scenarios dominated...
The effect of the Coriolis force due to impurity toroidal and poloidal rotation on in-out density asymmetry in a rotating tokamak plasma is identified. can be induced by with q*v_theta_z*omega_z, this case, when moving along magnetic field line from outboard side inboard flux surface, one sees positive force. proposed theory consistent ASDEX Upgrade experimental observations.
An improved theory for the neoclassical polarization drift of collisionless single ion with arbitrary time-varying radial electric field is presented. A guiding-center motion code used to numerically study a in model tokamak geometry. The results from are compared numerical and they agree each other very well. can be due fast field.
Abstract A B-spline Interpolation Transport Solver (BITS) based on a collocation method is developed. It solves transport equations as generalized interpolation problem, taking the first-order accuracy in time and second-order space along with predictor–corrector or under-relaxation iteration method. Numerical tests show that BITS can solve one-dimensional for tokamak plasma more accurately without additional computation cost, compared to finite difference solver which widely used existing codes.
Abstract The formation of electron thermal internal transport barriers (eITBs) is investigated by critical gradient threshold analysis for recent EAST experiments with dominant RF heating and low torque injection. ratio temperature to ion temperature, τ = T e / i , identified be the key parameter that triggers eITB in hot mode through turbulence suppression effect shielding. electron-temperature-gradient can greatly increased due strong weak electron–ion energy coupling. evolution found...
Equations of guiding-center motion without the coordinate singularity at magnetic axis have been derived from Lagrangian. The poloidal flux is suggested to be included as one nonsingular coordinates for computation orbit. numerical results based on different are verified using GCM code which canonical variables. A comparison performance among these and has carried out by checking conservation energy toroidal momentum. It found that in system, can greatly improved comparable variables...