This section configures the spatial information and moving window settings of the simulation and must be present in the input file. It accepts the following data:

  • xmin(x_dim), float, default = 0.0
  • xmax(x_dim), float, default = 0.0
  • if_move(x_dim) bool, default = .false.
  • move_u, float, default = -1.0

xmin, xmax - specify the lower and upper boundaries of the global simulation space at the beggining of the simulation in normalized units. Note that for cylindrical coordinates, the lower boundary of the radial dimension will always be set to -dr/2, where dr is the radial cell size, overriding user input.

if_move - specifies a whether the code should use a moving window at the speed of light in the specified directions. Setting this to .true. will override any boundary conditions for that direction you specify for Electro-Magnetic fields or particle species, except for the periodic boundaries set on the node_conf section.

move_u - specifies the normalized momentum of the moving window (i.e. beta * gamma). Note: in principle, negative momenta could be allowed, but are not currently implemented.

Here’s an example of a space section for a 2D run that sets the global simulation boundaries to [0.0,15.0] in the x1 direction and [0.0, 3.5] in the x2 direction. The simulation will use a moving window along the x1 direction.

space
{
  xmin(1:2) =  0.0, 0.0,
  xmax(1:2) =   15.0, 3.5,
  if_move(1:2) = .true.,.false.,
}