How to spawn new particles where particles collide? (Nuclear Fusion Reaction)

[carveid4]

Hi.  new to tyflow and glad to be here.

I am trying to make a fusion reaction animation, like what is happening in the sun. Two fast-moving heavy hydron atoms colliding with each other and form a helium atom and a neutron.


Here is what I have done so far for the moving particles effect:

The idea is to zoom into the sun and sees the reaction. When time slows down we see how the particle collisions in slow motion.

Here I have a simplified scene to test the collision and the spawn. Each ball is a Hydrogen atom.



I have added a PhysX shape to let the particles collide with themselves and a PhysX Collision to let them bounce inside the box. Min friction and Max restitution to let them bounce forever.

However how to make two new particles coming out of two colliding parent particles? Ideally, the parents will die and there will be two new separate new particles as a helium and a neutron.

2 red balls -> collide -> one green ball + one yellow ball

How do I accomplish this? 

Many thanks!