Information on volume-distributed sources for iterations in the space-charge repeat option.


Various options are available for specifying rays in an iterative space-charge calculation.


Two of the options are for volume-distributed sources, called ‘disc source’ and ‘rectangular source’. These options are available only for space-charge iterations (although they could also be used in other contexts by an experienced user, by manual editing).


Both these options generate rays inside a 3-dimensional volume. The shape of the volume is either a cylinder or a rectangular box. The distribution of starting positions is uniform in each direction. The initial directions of the rays are determined by the position of the pupil.


This type of option can be used only once in a list of space-charge iterations.