Wall Boundary conditions

Hi all,

I am trying to model induced circular motion of a particle by magnetic fields in a 2d geometry. I have particles moving to the edge of my circular surrounding wall and im having problems with getting the particles to move once they reach the wall. They tend to stick to the wall even though i have specified a bounce condition in the particle tracing module. I have included the laminar flow and magnetic fields module also. Any advice would be greatly appreciated!

Many thanks,

Phil