AC/DC
stationary; frequency domain; time dependent; frequency domain; eigenfrequency
stationary; time dependent; stationary source sweep
Fluid Flow
Single-Phase Flow
Plasma
Nonisothermal Plasma Flow
Equilibrium Discharges
Species Transport
1 This physics interface is included with the core COMSOL package but has added functionality for this module.
2 Requires the addition of the AC/DC Module.
3 Requires the addition of the RF Module.
4 This physics interface is a predefined multiphysics coupling that automatically adds all the physics interfaces and coupling features required.
computes the electron energy distribution function (EEDF) from a set of collision cross sections for some mean discharge conditions. The interface can be used as a preprocessing stage before solving a full space dependent model. The main purpose of this interface is to compute electron source coefficients and transport properties.
is used to compute the electron density and mean electron energy for any type of plasma. A wide range of boundary conditions are available to handle secondary emission, thermionic emission, and wall losses. This interface rarely needs to be used by itself as it makes up part of the application specific interfaces described later.
solves a mass balance equation for all nonelectron species. This includes charged, neutral, and electronically excited species. The interface also allows you to add electron impact reactions, chemical reactions, surface reactions, volumetric species, and surface species via the Model Builder. This interface rarely needs to be used by itself as it makes up part of the application specific interfaces described later.
can be used to model positive columns, DBD discharges, glow discharges, and corona discharges. The complicated coupling between the electron transport, heavy species transport, and electrostatic field is handled automatically by the software. Furthermore, the secondary emission flux from ion bombardment on an electrode is automatically computed and used in the boundary condition for electrons.
can be used to model capacitively coupled plasmas. Instead of solving the problem in the time domain, the periodic steady-state solution is computed. This avoids having to solve for tens or hundreds of thousands of RF cycles, which is typically how long it takes before the plasma reaches the periodic steady-state solution. This approach maintains all the nonlinearity of the model while dramatically reducing computation time. The physics interface accomplishes this by attaching an extra dimension to the underlying mathematical equations representing one RF cycle, and enforcing periodic boundary conditions in the aforementioned extra dimension.
can be used to model discharges sustained through induction currents. These discharges typically operate in the MHz frequency range. Inductively coupled plasmas (ICP) are important in plasma processing and plasma sources because the plasma density can be considerably higher than in capacitively coupled discharges. Inductively coupled plasmas are also attractive from the modeling perspective because they are relatively straightforward to model, due to the fact that the induction currents can be solved for in the frequency domain. This means that the RF cycle applied to the driving coil does not need to be explicitly resolved when solving. As such, the quasi steady-state solution is reached in relatively few time steps.
can be used to model discharges sustained through induction currents and that have a periodic RF biased electrode. This interface uses the Plasma, Time Periodic interface to solve the periodic steady state for the RF bias. The inductive currents are solved in the frequency domain as in the Inductively Coupled Plasma interface. This type of discharges are interesting because the plasma density and the ions flux at a surface can be controlled somewhat independently.
can be used to model discharges which are sustained through heating of electrons due to electromagnetic waves. These discharges typically operate in the GHz frequency range. Wave–heated discharges usually fall into one of two categories: discharges with no external DC magnetic field and discharges with a high intensity static magnetic field. If a suitably high DC magnetic field is present then electron cyclotron resonance (ECR) can occur where electrons continually gain energy from the electric field over 1 RF period. Modeling microwave plasmas involves solving equations for the electron density, mean electron energy, heavy species, the electrostatic potential, and the high frequency electric field. The high frequency electric field is computed in the frequency domain and losses are introduced via a complex plasma conductivity.
couples existent plasma interfaces with Laminar Flow and Heat Transfer in Fluids interfaces. Use these interfaces when there are important fluid velocities and when the background gas temperature depends strongly on the operation conditions.
multiphysics interface, available in 2D and 2D axisymmetric, is used to study equilibrium discharges in a magnetohydrodynamics (MHD) framework where the currents are out-of-plane. This multiphysics interface adds three single physics interfaces: Magnetic Fields, Heat Transfer in Fluids, and Laminar Flow, together with several multiphysics coupling features. The multiphysics couplings add the MHD coupling between the Magnetic Fields and the Laminar Flow interfaces. The multiphysics couplings also add heating and cooling of the equilibrium plasma by enthalpy transport, Joule heating and radiation loss.
multiphysics interface, available in 2D and 2D axisymmetric, is used to study equilibrium discharges in a magnetohydrodynamics (MHD) framework where the currents are in-plane. This multiphysics interface adds three single physics interfaces: Magnetic and Electric Fields, Heat Transfer in Fluids, and Laminar Flow, together with several multiphysics coupling features. The multiphysics couplings add the MHD coupling between the Magnetic and Electric Fields and the Laminar Flow interfaces. The multiphysics couplings also add heating and cooling of the equilibrium plasma by enthalpy transport, Joule heating and radiation loss as well as special boundary conditions to model the ion and electron heating at the plasma boundaries.
multiphysics interface, available in 3D, is used to study equilibrium discharges in a magnetohydrodynamics (MHD) framework. This multiphysics interface adds three single physics interfaces: Magnetic and Electric Fields, Heat Transfer in Fluids, and Laminar Flow, together with several multiphysics coupling features. The multiphysics couplings add the MHD coupling between the Magnetic and Electric Fields and the Laminar Flow interfaces. The multiphysics couplings also add heating and cooling of the equilibrium plasma by enthalpy transport, Joule heating, and radiation loss as well as special boundary conditions to model the ion and electron heating at the plasma boundaries.