Allows loading particles from an SDDS file. This is an alternative to using
a cathode and can provide essentially arbitrary particle distributions.
spiffe is a 2.5 dimensional code, the ``particles'' are really
rings at a given radius and longitudinal position.
filename = "particles.sdds",
This loads particles from the file
- synopsis and defaults:
STRING filename = NULL;
long sample_interval = 1;
double stiffness = 1;
- filename: Name of the SDDS file from which to take particle data.
The file must have the following columns with the following units:
- : longitudinal position in meters.
- : radial poition in meters. If the particle position is initially
outside the problem region or inside a metal volume, it will move
ballistically until it enters the problem region or emerges from the metal.
- : longitudinal momentum,
- : radial momentum,
- : azimuthal momentum,
- : charge, in Coulombs.
- sample_interval: Causes
spiffe to take only every
sample_interval particle from the file.
- stiffness: Allows making the beam artificially stiff. Equivalent
to increasing the particle mass by the given factor.