There's a mostly-lame mode that lays the particles out along a plane; the orientation of the plane depends on the rotation of the emission point (all old weapons with particles necessarily have skeletons, the particles emitters must be attached to a bone). For most things, the flat of the plane runs up the length of the weapon and out the sides. Perpendicular to the length of the weapon would seem neater, could make sort-of encircling halo effects. But in any case here's an example of how it is. Seems to be a bit unstable; the partcles there were set to have no direction or velocity.
Annnnd that's about the point where I lose interest and wonder why I blew a morning working on the tool to edit these.
They should replace the sk epic with the one you did.