Domain

Simulation Type

Change the environment to handle BEM charging, internal charging, FEM charging, radiation hardening, plasma dynamics, or PECVD, etching, sputtering. The corresponding dropdown optionswill appear.

Parallel Processes

Set the number of parallel processes used.

Minimum Time Step

Set the smallest time step increment the solver can use.

Maximum Time Step

Set the largest time step increment the solver can use.

End Time

Set the total length of the simulation.

Number of Time Steps

The number of time steps to simulate. The time steps begin as the minimum step size, then increase (limited by the max size) until the end time is reached.

Output Frequency

Define how often to write simulation results to the results file.

Time Sync

Synchronize the time domain between the Surface and Internal solvers, typically used for PIC simulations.

Internal Time Steps (s)

Set the time step size for each interval. If "Interval = SurfaceSync" this input has no affect.

Number of Internal Time Steps

Set the number of intervals for the Charge simulation. There can be more than one number listed, within the call file, which may be appropriate for an adaptive time-stepping scenario. For example Intervals = 10 20 50 would define a simulation with 80 total time steps (10 for the first set of time step sizes, then 20 and then 50. Intervals, Sizes and Output are required to have the same number of entries. Intervals = SurfaceSync sets the internal time steps to be equivalent to the surface charging time steps, which may be appropriate in a coupled simulation.

Internal Output Frequency

Define how often to write simulation results to the results file. Setting an ouput larger than 1 may be helpful for a simulation with many timesteps. For example, "Output = 10" means the simulation results are written to the file every 10th time step. If "Interval = SurfaceSync" this input has no affect. The output is determined by surface charging inputs.

Internal Solver

The specific solver to be used for internal charging simulations.Quasi-static relies solely on scalar potential.Full-wave incorporates vector potential to obtain solution.

Gauge

Options include Lorenz and Coulumb for guage fixing condition inaddition to the default option. It is recommended to use the Coulomb gauge for problems without a boundary condition for the scalar potential and for internal charging. Full wave typically uses Lorenz.

Conductive Scaling

Apply to more accurately calculate the charging of floating conductors.

Conductive Steps

Set the conductive scaling steps.

Secondary Electron Yield

Choose the model to describe the secondary electron yield interaction.

Surface Solver

Define the matrix set up and solution by choosing between the options below.

Surface Iterative Solver

Set the surface iterative solver

Surface Maximum Iterations

Set the max number of iterations the solver will go through regardless of convergence.

Surface Convergence Tolerance

Numerical tolerance for an 'acceptable' solution for the iterative solver. A smaller tolerance may give more accurate solutions but also take longer to reach convergence.

Surface Interpolation Order

Sets the interpolation order for the iterative solver.

Surface Preconditioner

Activate the use of preconditioning to solve the iterative matrix equation.

Matrix Fraction

Turn on the use of a sparse E-field matrix for the 2nd NN, NN and self-capacitance solvers.A value of 100% creates a full matrix for E-fields as done for the standard full-matrix solver.

Parallel Matrix Processes

Set the number of processes used for the initialization of matrices in the surface charging solver.The number of matrices used for the initialization is duplicated by this number, so this field is used to limit the amount of RAM required for the inversion process.

E-Field Limit

Turn on the analytical formulation of charge limiting due to positive electric fields in the surface charging solver.

Photo Barrier

Turn on the analytical formulation of the photo barrier formulation in the surface charging solver.

Charge Stability

Turn on stability controls for the surface charging solver (>1). Stability control is on by default, but may not be necessary for all models.

Shading

Turn on the shadowing calculation at the initialization stage of the surface charging solver. For large models, this may slow down initialization.

Matrix Approximation

Turn on the matrix approximation for the calculation of potentials from the currents calculated by the solver.By default, a closed analytical solution of the potential is used, but may introduce instability in the solver.

Adaptive Time Stepping

Turn on adaptive time stepping to refine the time step size when the gradients of the potentials are large.This tool is used when dealing with eclipse transitions.

Simulate Breakdown

Turn on/off the stochastic tree model solver for the simulation of arcs in solids.

Neighbor Breakdown Threshold

Set the probability that the adjacent node contributes to the arc propagation, effectively setting the branching probability.

Intra-Breakdown Conductivity

Set the conductivity in S/m of the materials as the arc propagates through the material, which defines how fast the treeing occurs for the fixed 10-ns time step.

Post-Breakdown Conductivity

Set the material conductivity in S/m once it has arced.

Breakdown Time Delay

[TimeDelay > 0]Optionally set a time delay in seconds for the start of the solver.

Flux Bins

Set a value of 1 to initialize flux calculation for the particle transport solver. Or, set an increasing list of comma-separated energy bins in MeV (i.e.: 0.2, 0.4, 0.6, 0.8, 1.0) to generate a results file that contains the flux of each particle species for each energy bin in 3D.

Package Selection

Enumerator for the charge physics package options.

Max Tree Depth

Set the maximum depth for the Octree used for the particle to element mapping. Setting a deeper tree maybe faster at searching, but it takes longer to build and uses more memory.

Parallel Transport Processes

[Must be greater than or equal to Parallel Processes]Set the number of processes used for particle transport. The particle transport tool does not share memory and can be scaled across multiple nodes.

Flux

Use a flux source with a threshold for coupled simulation.

Transport Field Coupling

Allows background fields to affect particle trajectories in the particle tracking feature.

Threshold

Set the threshold for coupled simulation.

Statistical Measure

Set the number of total macroparticles the PIC solver will track during the simulation.

Max Iterations

Set the number of PIC time steps to run (given they are smaller than the EM time steps).

Average Iterations

Set the iterations to use for average distribution of particles at the end of time steps.

PIC EM Model

Electromagnetic model for PIC sources

X

X-component

Y

Y-component

Z

Z-component

Number of Time Steps

Set the the number of total fluid times steps. The total length of the simulation will be determined by the amount of fluid steps.

Time Step Size

Set the time step size.

Output Frequency

Define how often to write simulation results to the results file. For example, 1 -> every time step, 2 -> every other time step, 3 -> every third time step.

Cycle Results

If Fluid Cycles is set to true, this simply enables tracking quantities averaged over the cycle duration provided. If Fluid Cycles is set to coupled, a more specific set of controls is put in place: The FEM information on intervals (number of time steps) and sizes (time step magnitude) should correspond to exactly one cycle duration. Fluid step should be at least as large as the cycle count times the total time for one cycle. Fluid cycle duration will be ignored, since the cycle duration is assumed to be given by the FEM intervals and sizes.This cycle will be repeated. The simulation of cycles will continue until the number of specified fluid intervals are finished.

Cycle Duration

If fluid cycles are set to true this provides the cycle time.

Cycle Count

Set the maximum cycles to check for fluid system to reach a new 'semi-equilibrium'. Only applicable if fluid cycles is set to coupled.

Reaction Rates

Turn on or off reactions rates and specifiy whether to use Charge Plus reaction rates, or import rates from a Chemkin file. Note: Even if fluid simulations are not being used, this sets the reaction rates for Full PIC, Hybrid PIC-Fluid, and Full Fluid simulations.

Fluid EM Model

Set the charge attribution from the fluid for the electromagnetic solver. Space Charge includes it as a charge source in the calculation of the potential,Conductivity does not add charge, but modifies the spatial conductivity of the body containing the fluid, and NULL does not contribute anything.

WORK IN PROGRESS

Import Chemkin Surface Interactions File

PIC Spatial Interpolation

Sets whether the charge should be interpolated onto the FEM mesh via nodes (Nodal) or interpolated on the elements (Elemental).

PIC Stepping

Sets the PIC time stepping method. Fully Explicit is a direct explicit leap frog time stepping. Implicit is a leap frog approach but with implicit stepping.

Stepping Implicit Factor

Implicit factor for implicit timestepping as a fraction of the timestep to implicitily step. A value of 0.5 will do half steps

Debye Screen Ratio

Ratio of the cell size to the Debye length at which Debye screening turns on.

Record Boundary Flux

Particle flux on boundary surfaces. Applies to both the fluid solver and PIC solver.

Flux Recording Rate

The integer, if greater than one, defines how often to write flux results to file.

PIC Secondary Electron Yield

Activate surface interactions of PIC particles with surface materials (only valid for surface materials). Requires materials_defined.dat and SEY boundary assignments. SEY boundary assignments format in .Call: "SEY Boundary (Boundary Index #) = Material Index # found in materials_defined.dat".

FEM Field Iterations

If this option is set to true, any update to the fields in the PIC simulation are implemented 'gradually'.

RF Nonlinear

Enable the RF Nonlinear source.

Implicit Factor

The Implicit factor weights the impliciation term in the Poisson equation.

Screening Factor

The screening factor allows a weighting for the Debye screening when the mesh scale is larger than the Debye length locally.

PIC Smoothing

To turn on PIC smoothing to help with limited statistics.

PIC Reaction Rates Smoothing

Smooths out the change in particle species due to inelastic scattering.

PIC Continuum Scattering

Converts scattering crosssections into reaction rates and calculates reactions based on the species averages.

Isotropy

Determines the amount of isotropy for scattering. A value of 1 is purely isotropic scattering.

PIC Renormalize

When false automatic renormalization is off. Set to true when PIC density boundary conditions and/or electron emmision surfaces are defined.

Slow PIC

Artificially slow the electron speed. Set to true to increase stability within the system. It is most helpful when the long-term behavior of the system is most relevant, rather than short-duration fluctuations.

PIC Surface Averaged Sheaths

Averages the quanties at a surface in order to calculate an average potential and current across the entire surface.

Mapped Background B-Field

Allows magnetic fields to be imported from external sources such as Ansys HFSS.

Pressure Gradient

Turn on the pressure gradient term in the fluid solver.

Fluid Compressibility

Turn on compressibility in the fluid solver.

Newton Iterations

May provide better numerical behavior in fluid systems with large spatial gradients.

Joule Heating

Turn on Joule heating in the fluid solver.

Conservation

True, track mass, temperature and momentum conservation.

Model Electron Fluid

Turn on if electrons are being modeled as a fluid. Only necessary when using fluid rates or coupling to Chemkin.

Electron Fluid Component

Specify the component number

Fluid Stabilization

Remove the Adapted Mesh region from accelerated fluid stepping.

Enable Finite Element Solver Options

Allows customization of the finite element solver.

Internal Polynomial Order

Set the polynomial order used for the solver method. Generally, it should be set to a value of 2. Each iteration takes longer with higher polynomials, but convergence happens faster.

Internal Max Iterations

Set the max number of iterations to obtain convergence.

Internal Tolerance

The allowed error to pass for convergence

Internal Preconditioner

Activate the use of preconditioning to solve the iterative matrix equation. This should typically be set to true as it helps decrease convergence time.

Adaptive Mesh Lower Limit

Sets a lower limit on the size of the adaptive mesh layer thickness.

Lower Limit

Lower adaptive mesh limit. The smallest thickness allowed.