COMSOL Multiphysics^® 6.0 Release Highlights

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.

Double-Headed Streamer in Nitrogen

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

Electron density and equipotential lines at 2.5 ns. An initial seed of electrons is placed between two electrodes that apply an initial electric field of 52 kV/cm to the gas. A negative and positive streamer propagate toward the electrodes.

Application Library Title:
streamer_2d
Download from the Application Gallery

DC Corona Discharge in a Point-to-Plane Configuration

A plasma DC corona discharge model showing the negative ion number density spatial distribution in the Prism color table.

Negative ion number density spatial distribution. A millimeter-sized elliptical electrode creates a high-intensity electric field where the corona discharge occurs. A ground plane is placed 10 cm away from the corona electrode. The creation and transport of charged species is solved self-consistently coupled with Poisson’s equation.

Application Library Title:
point_to_plane_dc_corona
Download from the Application Gallery

Plasma DC Arc

Plasma temperature spatial distribution of a plasma DC arc in a point-to-plane configuration. The high current flowing through the system creates a thermal plasma in a gap of a few centimeters. The plasma is considered a conductive fluid medium and is modeled using a magnetohydrodynamics approach.

Application Library Title:
plasma_dc_arc
Download from the Application Gallery

Plasma Pulsed Arc

Fluid velocity magnitude and streamlines for the high current part of the pulse on a plasma pulsed arc in a point-to-plane configuration. The high current flowing through the system creates a thermal plasma in a gap of a few centimeters. The thermal plasma is responsible to create a flow of 100 m/s within the gap.

Application Library Title:
plasma_pulsed_arc
Download from the Application Gallery

Coil Optimization of an ICP Reactor

A plot showing the power absorbed by the electrons in an ICP reactor with the optimized design in the Inferno color table.

Power absorbed by the electrons in an ICP reactor obtained with the optimized design. This model shows how shape optimization can be used to design the coils of an ICP reactor to obtain plasma uniformity and ion flux at the bottom surface; this is done by minimizing the gradient of the electron density in the reactor center.

Application Library Title:
icp_coil_optimization
Download from the Application Gallery

Transient Negative Mobility and Negative Differential Conductivity in Xenon

Temporal evolution of the electron drift velocity. This model presents a study showing the transient negative mobility and the negative differential conductivity effects in xenon. The stationary and time-dependent Boltzmann equation in the two-term approximation is used to compute the electron energy distribution function.

Application Library Title:
transient_negative_mobility
Download from the Application Gallery

COMSOL Multiphysics® 6.0 Release Highlights