87 citations · 573 across the 31 of their papers we have counts for
31 papers
High Order Explicit Lorentz Invariant Volume-preserving Algorithms for Relativistic Dynamics of Charged Particles
Yulei Wang, Jian Liu, Yang He
Lorentz invariant structure-preserving algorithms possess reference-independent secular stability, which is vital for simulating relativistic multi-scale dynamical processes. The s…
Stochastic simulation of collisions using high-order weak convergence algorithms
Wentao Wu, Jian Liu, Hong Qin
Electron collisions, described by stochastic differential equations (SDEs), were simulated using a second-order weak convergence algorithm. Using stochastic analysis, we constructe…
The role of magnetic moment in the collisionless pitch-angle scattering of runaway electrons
Chang Liu, Hong Qin, Eero Hirvijoki +2
Recently, the validity of the guiding-center approach to model relativistic runaway electrons in tokamaks has been challenged by full-orbit simulations that demonstrate the breakdo…
What breaks parity-time-symmetry? -- pseudo-Hermiticity and resonance between positive- and negative-action modes
Ruili Zhang, Hong Qin, Jianyuan Xiao +1
It is generally believed that Parity-Time (PT)-symmetry breaking occurs when eigenvalues or both eigenvalues and eigenvectors coincide. However, we show that this well-accepted pic…
On the physical mechanism of three-wave instabilities -- resonance between positive- and negative-action modes
Ruili Zhang, Hong Qin, Yuan Shi +2
Three-wave instability is a fundamental process that has important applications in many branches of physics. It is widely accepted that the resonant condition $ω_{z}\approxω_{x}+ω_…
A lattice Maxwell system with discrete space-time symmetry and local energy-momentum conservation
Jianyuan Xiao, Hong Qin, Yuan Shi +2
A lattice Maxwell system is developed with gauge-symmetry, symplectic structure and discrete space-time symmetry. Noether's theorem for Lie group symmetries is generalized to discr…
Improvement of training set structure in fusion data cleaning using Time-Domain Global Similarity method
Jian Liu, Ting Lan, Hong Qin
Traditional data cleaning identifies dirty data by classifying original data sequences, which is a classimbalanced problem since the proportion of incorrect data is much less th…
Preference-based performance measures for Time-Domain Global Similarity method
Ting Lan, Jian Liu, Hong Qin
For Time-Domain Global Similarity (TDGS) method, which transforms the data cleaning problem into a binary classification problem about the physical similarity between channels, dir…
Time-domain global similarity method for automatic data cleaning for multi-channel measurement systems in magnetic confinement fusion devices
Ting Lan, Jian Liu, Hong Qin +1
To guarantee the availability and reliability of data source in Magnetic Confinement Fusion (MCF) devices, incorrect diagnostic data, which cannot reflect real physical properties…
Local Energy Conservation Law for Spatially-Discretized Hamiltonian Vlasov-Maxwell System
Jianyuan Xiao, Hong Qin, Jian Liu +1
Structure-preserving geometric algorithm for the Vlasov-Maxwell (VM) equations is currently an active research topic. We show that spatially-discretized Hamiltonian systems for the…
Largest Particle Simulations Downgrade the Runaway Electron Risk for ITER
Jian Liu, Hong Qin, Yulei Wang +6
Fusion energy will be the ultimate clean energy source for mankind. One of the most visible concerns of the future fusion device is the threat of deleterious runaway electrons (REs…
Canonical symplectic structure and structure-preserving geometric algorithms for Schrödinger-Maxwell systems
Qiang Chen, Hong Qin, Jian Liu +4
An infinite dimensional canonical symplectic structure and structure-preserving geometric algorithms are developed for the photon-matter interactions described by the Schrödinger-M…
Explicit symplectic algorithms based on generating functions for relativistic charged particle dynamics in time-dependent electromagnetic field
Ruili Zhang, Yulei Wang, Yang He +4
Relativistic dynamics of a charged particle in time-dependent electromagnetic fields has theoretical significance and a wide range of applications. It is often multi-scale and requ…
Geometric field theory and weak Euler-Lagrange equation for classical relativistic particle-field systems
Peifeng Fan, Hong Qin, Jian Liu +2
A manifestly covariant, or geometric, field theory for relativistic classical particle-field system is developed. The connection between space-time symmetry and energy-momentum con…
Lorentz Covariant Canonical Symplectic Algorithms for Dynamics of Charged Particles
Yulei Wang, Jian Liu, Hong Qin
In this paper, the Lorentz covariance of algorithms is introduced. Under Lorentz transformation, both the form and performance of a Lorentz covariant algorithm are invariant. To ac…
The Accurate Particle Tracer Code
Yulei Wang, Jian Liu, Hong Qin +1
The Accurate Particle Tracer (APT) code is designed for large-scale particle simulations on dynamical systems. Based on a large variety of advanced geometric algorithms, APT posses…
Photons, phonons, and plasmons with orbital angular momentum in plasmas
Qiang Chen, Hong Qin, Jian Liu
Exact eigen modes with orbital angular momentum (OAM) in the complex media of unmagnetized homogeneous plasma are studied. Three exact eigen modes with OAM are discovered, i.e., ph…
High order volume-preserving algorithms for relativistic charged particles in general electromagnetic fields
Yang He, Yajuan Sun, Ruili Zhang +3
We construct high order symmetric volume-preserving methods for the relativistic dynamics of a charged particle by the splitting technique with processing. Via expanding the phase…
Explicit high-order noncanonical symplectic algorithms for ideal two-fluid systems
Jianyuan Xiao, Hong Qin, Philip J. Morrison +4
An explicit high-order noncanonical symplectic algorithm for ideal two-fluid systems is developed. The fluid is discretized as particles in the Lagrangian description, while the el…
Hamiltonian particle-in-cell methods for Vlasov-Maxwell equations
Yang He, Yajuan Sun, Hong Qin +1
In this paper, we develop Hamiltonian particle-in-cell methods for Vlasov-Maxwell equations by applying conforming finite element methods in space and splitting methods in time. Fo…
Multi-scale Full-orbit Analysis on Phase-space Behavior of Runaway Electrons in Tokamak Fields with Synchrotron Radiation
Yulei Wang, Hong Qin, Jian Liu
In this paper, the secular full-orbit simulations of runaway electrons with synchrotron radiation in tokamak fields are carried out using a relativistic volume-preserving algorithm…
On the structure of the two-stream instability -- complex G-Hamiltonian structure and Krein collisions between positive- and negative-action modes
Ruili Zhang, Hong Qin, Ronald C. Davidson +2
The two-stream instability is probably the most important elementary example of collective instabilities in plasma physics and beam-plasma systems. For a warm plasma with two charg…
Explicit symplectic algorithms based on generating functions for charged particle dynamics
Ruili Zhang, Hong Qin, Yifa Tang +3
Dynamics of a charged particle in the canonical coordinates is a Hamiltonian system, and the well-known symplectic algorithm has been regarded as the de facto method for numerical…
Neoclassical Pitch-Angle Scattering of Runaway Electrons
Jian Liu, Yulei Wang, Hong Qin
It is discovered that the tokamak field geometry generates a pitch-angle scattering effect for runaway electrons. This neoclassical pitch-angle scattering is much stronger than the…