RayCast on particle system

Hi,

I have setup a Particle System with collison for particles working correctly. I wanted to use a Physics.SphereCastAll to see if some particles are in the sphere. As i understand it, i need to put a collider on the particles. I can't figure out how to.

I have already set up a collision Layer and my RayCast Works on RigideBodies and Colliders on that same layer.

How can I set the particles to be in the same Layer as the RayCast ?