Electrostatic field solving is done to high accuracy using the Boundary Element Method (BEM) rather than traditional FEM or FDM methods. The BEM has unique advantages and is well-suited to space-charge, cathode problems and nano-structures in the presence of large electrodes. Adaptive surface meshes get smaller where accuracy is critical. The BEM even easily simulates fine meshes and non-enclosed systems. Low-frequency oscillations, such as in a quadrupole, may also be simulated.
Particle trajectories of charged particles are calculated (Bulirsch-Stoer), accurately accounting for space-charge and relativistic effects. Space-charge is handled with iterative convergence tube and mesh methods – accuracy of 1% against theoretical results have been obtained.
Cathode emissions limited by space charge are simulated, including thermionic, field and extended Schottky emissions. Supports Child’s Law/Langmuir, Fowler-Nordheim and Richardson-Dushman relationships, plus user-defined properties. CPO specially handles space-charge effects at the critical cathode region.
Secondary emissions can be generated when a particle hits an electrode. The current multiplication factor and energy/angular distributions of the secondaries are chosen by the user.
Particle scattering and losses due to grid, background gas or secondary emissions are given in the examples included in the scattering version of CPO. Particle-particle scattering inside the beam is possible with the stochastic version. User-defined routines can be written in C++.
Magnetic elements of various types such as solenoids, wire loops and user-defined fields are avilable. Various contour and field plots can be displayed.
Aberration coefficients and lens properties may be calculated directly. An iterative automatic focusing option can find optimum electrode voltages.
Dielectrics calculations now available as a special module!