Smoothing functions are commonly used to reduce numerical noise arising from coarse sampling of particles in particle-in-cell (PIC) plasma simulations. When applying smoothing symplectic algorithms, the conservation structure should be guaranteed preserve good properties. In this paper, we show how construct a variational multi-symplectic PIC algorithm with for Vlasov-Maxwell system. The and reduction make specifically suitable simulating long-term dynamics plasmas, such as those...

Abstract Tokamaks allow to confine fusion plasma with magnetic fields. The prediction/reconstruction of the last closed-flux surface (LCFS) is one primary challenges in control configuration. evolution time LCFS determined by interaction between actuator coils and internal tokamak plasma. This task requires real-time capable tools deal high-dimensional data high resolution at same time, where a wide range input state responses adds an additional layer complexity. In this work, we present...

In this paper, the nonlinear mode conversion of extraordinary waves in nonuniform magnetized plasmas is studied using variational symplectic particle-in-cell simulation. The accuracy simulation guaranteed by long-term and conservativeness algorithm. spectra electromagnetic wave, evolution wave reflectivity, energy deposition profile, parameter-dependent properties radio-frequency during are investigated. It illustrated that effects significantly modify physics injection plasmas. evolutions...

An explicit high-order noncanonical symplectic algorithm for ideal two-fluid systems is developed. The fluid discretized as particles in the Lagrangian description, while electromagnetic fields and internal energy are treated discrete differential form on a fixed mesh. With assistance of Whitney interpolating forms, this scheme preserves gauge symmetry field, pressure field naturally derived from energy. whole system solved using Hamiltonian splitting method discovered by He et al., which...

Abstract A neural network model of tokamak discharge is developed based on the experimental dataset a superconducting long-pulse (EAST) campaign 2016–2018. The purpose to reproduce response diagnostic signals actuator without introducing additional physical models. In present work, curves electron density n e , stored energy W mhd and loop voltage V were reproduced from series signals. For average similarity between modeling results data achieve 89% 97%, respectively. promising demonstrate...

In this work, a purely data-driven discharge prediction model was developed and tested without integrating any data or results from simulations. The based on the experimental Experimental Advanced Superconducting Tokamak (EAST) campaign 2010-2020 discharges can predict actual plasma current $I_{p}$, normalized beta $\beta_{n}$, toroidal $\beta_{t}$, poloidal $\beta_{p}$, electron density $n_{e}$, store energy $W_{mhd}$, loop voltage $V_{loop}$, elongation at boundary $\kappa$, internal...

The period with which radio bursts recur on Jupiter (the System III period) is defined by the IAU to be 9h 55m 29.71s based early astronomical data, and generally assumed represent of rotation Jovian interior. A recent estimate from burst data 0.025s shorter than value. In apparent contradiction observations, in situ measurements using orientation dipole moment are consistent original inconsistent suggested decrease. Thus, present should retained as best rate Since generated near base Io...

To determine the Jovian internal rotation rate, historically one has used repetition period (periodicity) of decametric and decimetric radio waves. The with which waves recur on Jupiter (the System III period) was defined by IAU in 1965 to be 9h 55m 29.71s, based early astronomical data. A more direct way this is examine rate dipole field. We have done using Galileo, Pioneer 10 11, Voyager 1 2, Ulysses data over a 25‐year period. find small drift apparent longitude axis that statistically...

A kinetic simulation algorithm for high-frequency electromagnetic waves has been developed based on the gyrocenter-gauge theory. The magnetized plasma system is simulated in gyrocenter coordinate system. distribution function F sampled gyrocenter, parallel velocity, and magnetic moment coordinates. S Kruskal rings shares first five coordinates with F. integral of pullback transformation directly calculated using Monte Carlo method an explicit difference scheme Maxwell’s equations terms...

A new numerical code solving the conservative perturbed resistive magnetohydrodynamic (MHD) model is developed. Numerical tests of ideal Kelvin-Helmholtz instability and double tearing mode (DTM) show its capability in linear nonlinear MHD instabilities. The DTM evolution 2D geometry numerically investigated with low guiding field Bz0, short half-distance y0 between equilibrium current sheets, small resistivity η. interaction islands on two initial sheets may generate an unstable flow driven...

Explicit and spontaneous breaking of spacetime symmetry under diffeomorphisms, local translations, Lorentz transformations due to the presence fixed background fields is examined in Einstein–Cartan theory. In particular, roles torsion violation translation invariance are highlighted. The nature types that can arise how they cause discussed. With explicit breaking, potential no-go results known exist, which if not evaded lead inconsistencies between Bianchi identities, Noether equations...

Abstract Particle-in-cell simulations have been conducted to investigate the parametric decay processes of radiofrequency waves in ion cyclotron range frequency inhomogeneous plasmas. By choosing parameters close those Bernstein wave heating experiments on HT-7 tokamak (Li et al 2001 Plasma Phys. Control. Fusion 43 1227–38 ), channels similar experimental observations found simulations. It is shown that due strong inhomogeneity edge plasma, layers may exist where selection rules mode–mode...

Laser ablation is able to produce plasmas containing neutrals, ions, clusters, and nanoparticles, which can all act as emitters of harmonics from ultrashort laser pulses. Here the efficient low- high-order harmonic generation (HHG) femtosecond pulses carbon produced by nanosecond demonstrated. The efficiencies clusters are analyzed using delayed graphite. We show that be considered sources in 40-100 nm spectral range. This approach double-pulse configuration HHG applied for studying other...

Abstract In recent decades, tokamak discharges with zero total toroidal current have been reported in experiments, and this is one of the key problems alternating (AC) operations. An efficient free-boundary equilibrium code developed to investigate such advanced reversal configuration. The calculation results show that can maintain finite pressure also has considerable effects on position X-point magnetic separatrix shape, hence strike point divertor plates, which extremely useful for...

Abstract In magnetically confined plasma research, the understandings of small and large perturbations at equilibrium are both critical for controlling steady state operation. Numerical simulations using original MHD model can hardly give clear picture perturbations, while non-conservative perturbed may break conservation law, unphysical results when grow after long-time computation. this paper, we present a nonlinear conservative by splitting primary variables in equations into part part,...

Detailed analysis of the low frequency instability is performed in a linear magnetized steady state plasma device. Identification and modification are presented.

Abstract Numerical methods based on gyrocenter gauge kinetic theory are suitable for first principle simulations of high frequency waves in magnetized plasmas. The δf PIC simulation linear rf wave has been previously realized. In this paper we further develop a full-f nonlinear algorithm appropriate the physics cases calculated as benchmark GyroGauge code, meanwhile rf-wave phenomena studied. technique and advantage reduction numerical noise also discussed.

In recent years, machine-learning (ML) research methods have received increasing attention in the tokamak community. The conventional database (i.e., MDSplus for tokamak) of experimental data has been designed small group consumption and is mainly aimed at simultaneous visualization a amount data. ML access patterns fundamentally differ from traditional patterns. typical increasingly showing its limitations. We developed new management system suitable based on advanced superconducting (EAST)...

Due to the complexity, chaotic behavior, and non-linear nature of tokamak plasma dynamics, modeling discharges poses a formidable challenge. This task necessitates accurate prediction evolution diagnostic signals, entailing resolution sequence-to-sequence time series problem. In this study, we propose novel framework for discharge modeling, termed PCC-Trans framework, which integrates feature selection method based on Pearson correlation coefficient (PCC) Transformer, enhances predictive...

The modelling and analysis of complex physical systems can be approached through data-driven physics-driven methods. To leverage their different advantages, it is necessary to couple multiple computational models that use However, integrating these requires additional work due requirements characteristics. An integrated analytical tool has been developed for the tokamak plasma magnetic equilibrium problem in confinement fusion. It integrates models. Two execution modes have designed optimize...