Use the Space Charge Limited Emission multiphysics coupling () to model the space charge limited emission of electrons from a surface.

The Label is the default multiphysics coupling name.

The Name is used primarily as a scope prefix for variables defined by the coupling node. Refer to such variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different coupling nodes or 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 multiphysics coupling in the model) is scle1.

Enter an Electric potential at emission surface V0 (SI unit: V). The default value is 0.

Enter the Number of particles per release N (dimensionless). The default value is 1000.

Enter the Position offset os (SI unit: m). The default value is 1 mm. This should be smaller than the length scale of the model geometry, but if it is several orders of magnitude smaller, it may become difficult for the model to converge.

Select the Initial value of electric potential in extra dimension — Automatic (the default) or User defined. For User defined enter the value for Vxd,0 (SI unit: V). The default value is 1 V.

Select the Mesh settings: Automatic (the default) or User defined. For User defined enter values for the following settings:

This section defines the physics involved in the multiphysics coupling. By default, the applicable physics interface is selected in the Source and Destination lists.

You can also select None from either list to uncouple the node from a physics interface. If the physics interface is removed from the Model Builder then the applicable list defaults to None as there is nothing to couple to.