Particle-in-cell Schemes Research Articles

Asymptotic-Preserving Particle-In-Cell method for the Vlasov–Poisson system near quasineutrality

This paper deals with the numerical resolution of the Vlasov–Poisson system in a nearly quasineutral regime by Particle-In-Cell (PIC) methods. In this regime, Classical PIC methods are subject to stability constraints on the time and space steps related to the small Debye length and large plasma frequency. Here, we propose an “Asymptotic-Preserving” PIC scheme which is not subjected to these limitations. Additionally, when the plasma period and Debye length are small compared to the time and space steps, this method provides a consistent PIC discretization of the quasineutral Vlasov equation. We perform several one-dimensional numerical experiments which provide a solid validation of the method and its underlying concepts, and compare the method with Classical PIC and Direct-Implicit methods.

Laboratory Experiments for Code Validation of Multiutility Spacecraft Charging Analysis Tool (MUSCAT)

The multiutility spacecraft charging analysis tool (MUSCAT), a spacecraft charging analysis software, has been developed as a collaboration work between Japan Aerospace Exploration Agency and Kyushu Institute of Technology. Laboratory experiments for fundamental code validation were carried out in both facilities' plasma chambers. MUSCAT is a particle simulation code based on particle-in-cell (PIC) and particle tracking (PT) algorithms capable of calculating the floating-body potential of a spacecraft with respect to the plasma potential. Three experiments were carried out regarding spacecraft-plasma interaction phenomena important in LEO and PEO. A Langmuir probe was used to measure the current collection and potential distribution in static plasma to validate the PIC and PT schemes. The floating potential of an object in plasma with an energetic electron component was measured to validate the floating-body calculation as well as the PT scheme. Current collection and potential distribution in the wake structure were measured to validate the PIC and PT scheme in flowing plasma condition. The experimental results and the simulation results agreed very well in all the three experiments, validating the accuracy of the MUSCAT solver.

Electromagnetic Particle‐In‐Cell simulation on the impedance of a dipole antenna surrounded by an ion sheath

We have newly developed a numerical tool for the analysis of antenna impedance in plasma environment by making use of electromagnetic Particle‐In‐Cell (PIC) plasma simulations. To validate the developed tool, we first examined the antenna impedance in a homogeneous kinetic plasma and confirmed that the obtained results basically agree with the conventional theories. We next applied the tool to examine an ion‐sheathed dipole antenna. The results confirmed that the inclusion of the ion‐sheath effects reduces the capacitance below the electron plasma frequency. The results also revealed that the signature of impedance resonance observed at the plasma frequency is modified by the presence of the sheath. Since the sheath dynamics can be solved by the PIC scheme throughout the antenna analysis in a self‐consistent manner, the developed tool has feasibility to perform more practical and complicated antenna analyses that will be necessary in real space missions.

Development of a Time-Independent Particle-in-Cell Code for Simulating DC Discharges in Inertial Electrostatic Confinement Devices

A two-dimensional numerical code has been developed for simulating dc discharges in inertial electrostatic confinement (IEC) fusion devices. Unlike the existing IEC codes, the developed code is not based on Monte Carlo scheme by the use of random number nor time-domain particle-in-cell (PIC) method, aiming at a drastic reduction of computational efforts. It is based on a time-independent scheme, i.e. iterative calculations of particle-tracking and induced self-field, leading to a much faster convergence than the time-domain PIC scheme on steady-state self-consistent solutions. Also, a new scheme for atomic process treatment is proposed, which is completely free from the inherent difficulty of Monte Carlo method, i.e. requiring many particles for simulating rare events. Preliminary numerical result from the this code showed agreement with experimental helium discharge characteristics in an IEC device.

A new guiding centre PIC scheme for electromagnetic highly magnetized plasma simulation

A new implicit fully electromagnetic particle in cell (PIC) method is presented in which the full ion dynamic and all the electron guiding centre drifts of a highly magnetized plasma are retained. We show that the electron drifts do not have to be described explicitly, and that they can be simulated using a simple but efficient linear direct implicit method. Tests and simulations using the new scheme are presented.

A particle‐in‐cell sea‐ice model

Abstract Fronts or discontinuities in geophysical flows are often smoothed in numerical models owing to artificial diffusion and dispersion introduced by the advection algorithm. This is a particular problem in operational sea‐ice forecasting where the position of the ice edge must be accurately predicted. The particle‐in‐cell (PIC) scheme avoids artificial smoothing by partitioning the ice volume into individual particles whose motion is integrated in a Lagrangian sense. The velocity field is obtained by solving the momentum equation on an underlying fixed Eulerian grid. Comparisons between the PIC scheme and more conventional advection algorithms are presented using both idealized and observed forcing fields. An advantage of the PIC model is that the resolution of the underlying Eulerian grid (on which the computationally expensive momentum equation is solved) can be chosen to represent the spatial variability of the forcing fields (winds and currents) rather than to minimize advection errors. A large number of particles per unit area can be used to resolve features of interest while maintaining only a sparse particle distribution elsewhere. The model is readily extended to include additional particles representing, for example, an oil spill.