But collisions impede all orbital planes not in step with the resultant angular momentum of t As collisions occur, some particles move into tighter orbits or drop into the core while others go into looser orbits within the accretion disk following a plane consistent with the angular momentum of the local system outside the core. The chance of a collision from an incoming particle is related proportionally with the density and thickness of the accretion disk in its path as well as the speed of transit through the disk. Therefore the chance of a particle colliding within the disk decreases as the angle of approach varies from 0 to 90 degrees. Near the core of the forming star in the accretion disk an eye exists where dropping particles are sufficient in number to hamper close orbits. The star is not ejecting material but simply holding material in orbit.
Illumination is provided by heating due to collisions between particles.
Observed beading within a jet may be due clumping within the original dust cloud. The accretion disk is not a barrier to material reaching the star's core. The disk is there as a storehouse for the angular momentum imbalance of the incoming dust cloud. It varies in size, shape, and orbital plane throughout star formation as dictated by dust particles within its influence. We know from our own solar system that an accretion disk can condense into planets which orbit the star in the plane of the original accretion disk.