Make orb_light "start"

[Damascus]

I'm using CreateParticleSystematEntity to create a custom PS similar to the orb_light one, but yellow instead of blue. However, the problem I'm having is that when I create it, it doesn't "emerge" or "spread" from the source like in other PS's, but the whole thing appears at once with all of the light already around it. Does anyone know how i can get the PS to start with nothing and have the light spread from the center to its full form?