Couldn't you shoot an electron bream ahead of the ship to ionize the atoms and the deflect them with a magnetic field?
I read a paper on the topic a few years back. My recollection is that once you go faster than about 0.3c it becomes impossible to shed heat faster than you gain it from collisions with Helium. I'll try to dig it up.
You could change the distribution of the forces at best but I'm not sure whether that could be enough...
Radiation hazard of relativistic space flight https://arxiv.org/abs/physics/0610030