A particle accelerator smashes streams of particles head on, but can it simulate properly the internal structure of a star before supernova where unbelievable f

A particle accelerator smashes streams of particles head on, but can it simulate properly the internal structure of a star before supernova where unbelievable forces are occurring in 3 dimensions in relative stability? I'd think to simulate you basically need to prevent the electrons from going anywhere, and the only place to go is inside the nucleus, where the strict rules of quantum mechanics and particle physics dictate they get merged with protons to form neutrons. Do we have anything besides tokamaks for smushing things together? Tokamaks seem to peak out at low-energy fusion reactions, but all I read about tokamaks is engineering focused on net-positive fusion.