CST2013: Wakefield Solver Problem Handling

This page contains a list of the most important warning and error messages in the context of the Wakefield Solver together with a detailed explanation of the meaning and proposal for handling and resolution.

Unable to solve the electrostatic problem for the interface region. Memory for XXX mesh points is required, but the maximum number of allowed points is XXX.

Particle beams with a beta value below or equal 0.999 are treated differently than beams with a beta larger than 0.999. If beta was chosen to be less than 0.999 a full 3D electrostatic problem must be solved before the wake-simulation is started. This is necessary to imprint the eigenfield of the moving charge at the calculation domain's boundaries. Depending on the beta value and the maximum stable time step of the wakefield simulation, this can be a very time- and memory consuming operation.

For ultra-relativistic beams with a beta value above 0.999 the eigenfield can be determined by solving a 2D electrostatic problem which requires a very small amount of memory only.

In case this error message appears several actions can be taken:

• Relax the mesh to increase the maximum stable timestep of the wakefield simulation.

• Reduce the number of mesh points in the interface region in order to downsize the 3D electrostatic problem.

• Use transversal symmetry conditions  in order to downsize the 3D electrostatic problem.

• Choose a beta value larger than 0.999 if applicable.

• Increase the maximum number of allowed points with the VBA command: Solver.MaxPointsBeamInterfaceCalc "XXX"