SCALA
Space charge simulation captures the coupling between electric fields and continuous high current particle beams passing through them. Beams are discretised into representative particle trajectories carrying quantised currents, which lead to an iteratively determined self-consistent distribution of electric field and trajectories.
Beams may enter the model from electrodes simulating thermionic emission, field effect emission or emission from the surface of a plasma. Alternatively, the user may specify the beam current density distribution at an input face or define a set of individual "beamlets". Secondary and backscattered emission from surfaces where the beam impacts are available. Beam energy loss and secondary emission due to gas molecule collision may also be included. |  |
The effect of a superimposed magnetic field distribution may also be taken into account when the trajectories are determined. Magnetic self field from very high current beams is also an option.
Space charge simulation also addresses multi-physics applications where the impact of the particle beam or secondary emission causes charge build up on dielectric components that are not perfect insulators. Coupling space charge and Tosca lossy dielectric simulations supports this capability.
Multi-physics simulations additionally support the effects of changes in material properties due to temperature rise. Thermal modelling using Tempo may derive heat sources from surface loss intensity due to beam impact and/or volume loss intensity in the lossy dielectrics. Specifying temperature dependent material properties in the space charge simulation allows their effect on device performance to be determined.