How would I create a cylindrical source

@srichr221 When you assign source.space, it needs to be a “spatial distribution” (list of valid classes here). To get a cylindrical shape, you can either:

  1. Use the CylindricalIndependent class. An example close to this is described here.
  2. If your cylinder corresponds to the shape of a Cell, you can use a source with any spatial distribution that completely covers the cylinder and then use cell rejection (i.e., only positions sampled within the cell are accepted) with:
    my_source = openmc.Source(space=..., domains=[cell_to_reject_on])