Plasma Module Updates

For users of the Plasma Module, COMSOL Multiphysics® version 6.0 brings consistent and inconsistent stabilization for the transport of charged species, stationary and frequency-stationary study steps to the Plasma interface, and time dependency to the Boltzmann equation in the two-term approximation. Read more about these Plasma Module updates below.

Consistent Stabilization

The Plasma interface now includes consistent stabilization, based on streamline diffusion, for the electron and ion transport equations. With this new functionality, you can solve high Péclet number systems such as corona discharges and streamers. You can see this functionality in use in the DC Corona Discharge in a Point-to-Plane Configuration and Double-Headed Streamer in Nitrogen models.

A 2D plot showing the electron density and equipotential lines of a double-headed streamer model at 2.5 ns. Electron density and equipotential lines at 2.5 ns.

Stationary and Frequency-Stationary Study Steps

When using the Plasma interface, you can now add stationary and frequency-stationary study steps. These stationary approaches allow for fast parameterizations and convenient use of existing optimization technology in COMSOL Multiphysics®. The computation time is greatly reduced for DC and ICP discharges when using a stationary solver. The Coil Optimization of an ICP Reactor model uses a frequency-stationary study step when optimizing the coil position to increase plasma uniformity.

Two plots showing the power absorbed by the electrons in a ICP reactor with the initial design on top and the optimized design on the bottom in the Inferno color table. Power absorbed by the electrons obtained with the initial design (left) and the optimized design (right).

Improved Stability of the Equilibrium Discharge Interfaces

The Equilibrium Discharges interfaces have faster and more stable solutions as a result of changes to the plasma/fluid properties, as well as the solver settings. You can experience these improvements in the existing Inductively Coupled Plasma (ICP) Torch model, as well as in two new models: Plasma DC Arc and Plasma Pulsed Arc.

Fluid velocity magnitude and streamlines of a plasma pulsed arc model. Fluid velocity magnitude and streamlines for the high current part of the pulse.

Time Dependency for the Boltzmann Equation in the Two-Term Approximation

The Time Dependent study type is now available for the Boltzmann Equation, Two-Term Approximation interface with which you can study problems where the electric field cannot be assumed constant on the time scale of the collisions. The Transient Negative Mobility and Negative Differential Conductivity in Xenon model shows this new functionality.

A 1D plot showing the electron energy distribution function with the drift velocity on the y-axis and time on the x-axis. Temporal evolution of the electron drift velocity.

New Tutorial Models

COMSOL Multiphysics® version 6.0 brings several new tutorial models to the Plasma Module.