Inverted Particle Emitter

Okay, so I want to make an ellipsoid particle emitter that spawns the particles at the surface of the ellipsoid and emits them into the center, sort of like a black hole effect or something. Any known methods?

Set the ellipsoid to near the outer radius, the MinEmitterRange to the inner radius, and the Z tangent velocity to something negative. Then ensure their maxEnergy is small enough that they die before getting to the centre.

alt text