The Charge Transport (ct) interface (), found under the Plasma branch () when adding a physics interface, solves for the space charge density of one type of charge carrier in regard of the polarity (i.e. positive or negative charge carriers). The charge carriers can be transported by migration in the electric field and convection. In the Corona interface the Charge Transport interface is coupled to the Electrostatics interface to model corona discharges.

When this physics interface is added, these default nodes are also added to the Model Builder — Transport Properties, No Flux (the default boundary condition), and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions. You can also right-click Charge Transport to select physics features from the context menu.

The Label is the default physics interface name.

The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.

The default Name (for the first physics interface in the model) is ct.

Select the Convection check box to add convection to the default migration in the electric field transport mechanism. The selection adds the section Convection on the Transport Properties node.

To display this section, click the Show button () and select Stabilization. There are two consistent stabilization methods available — Streamline Diffusion and Crosswind diffusion. By default both methods are selected. Streamline and crosswind diffusion stabilization adds artificially diffusion in the direction of the streamlines and in the direction perpendicular to the streamlines, respectively, to stabilize the numeric solution of a migration/convection-dominated PDE.

When the Crosswind diffusion check box is selected, a weak term that reduces spurious oscillations is added to the transport equation. The resulting equation system is always nonlinear.

To display this section, click the Show button () and select Stabilization. This method is equivalent to adding a isotropic diffusion term to the equations in order to dampen the effect of oscillations by making the system somewhat less dominated by convection. By default, the Isotropic diffusion check box is not selected, because this type of stabilization adds artificial isotropic diffusion and affects the accuracy of the original problem. If required, select the Isotropic diffusion check box and enter a Tuning parameter as a scalar positive value. The default value is 0.25. A higher value adds more isotropic diffusion

To display all settings available in this section, click the Show button () and select Advanced Physics Options. The space charge density variable is set to use Linear elements by default. The Value type when using splitting of complex variable is set to Complex by default.

The dependent variables (field variables) is the Space Charge Density. The name can be changed but the names of fields and dependent variables must be unique within a model.