Mesh Parameters

The number of grid points for the radiation field along a single axis. The total number for the mesh is NCAR². NCAR must be an odd number to cover the undulator axis with one grid point. Do not exceed NCMAX defined in the source file 'genesis.def'.

Flag to set the boundary condition for the field solver. The options are Direchlet boundary condition (LBC = 0) and Neumann boundary condition (otherwise). Anyhow the grid should be chosen large enough so that the choice of LBC should not change the results.

GENESIS 1.3 estimates the size of the grid on which the radiation field is discretized by scaling the averages size of the initial radiation field and beam size with RMAX0. The explicit size is [-DGRID,DGRID] in both dimensions with DGRID = RMAX0(_r,beam+_r,field). The electron beam size is the rms sum of RXBEAM and RYBEAM while the radiation field size is calculated with ZRAYL and ZWAIST.

Any value larger than zero explicitly sets the grid size, overruling the calculation by the RMAX0-parameter.

Number of longitudinal Fourier components for space charge calculation. NSCZ must be greater than 0 to include space charge but less than (2NBINS+2) for valid results.

Number of azimuthal modes for space charge calculation.

Number of radial grid points, on which the space charge field is evaluated. The radial axis is automatically chosen by GENESIS 1.3 to be twice as long as the maximum offset of macro particles relative to the center of the electron beam. This excludes effects of the boundary condition even for the case of narrow beams.

Explicitly defines the radial grid size for space charge calculations when set to a positive value. Otherwise, Genesis calculates the grid size from the current size of the electron beam.

If set to a non-zero value then the space charge field is updated at each of the 4 Runge-Kutta integration steps instead of the default behavior, where the space charge field is claculated only once before the Runge-Kutta integration. It increases the stability and precision of the space charge field but it comes with a cost in slower execution speed.