The trouble there is that, in order to attenuate high-energy radiation like the cosmic rays under discussion, you need something that's either extremely dense or extremely thick, and ideally both - dense so a speeding particle is more likely to hit it instead of zipping past between the atoms, thick so that Bremsstrahlung X-rays get absorbed before they reach human tissue susceptible to ionization injury.

Both of these are physical necessities, and both militate directly against the idea of a light, comfortable radiation-proof suit or dome. They're also not something that can be solved by incremental improvements in materials science - as sensible to imagine that we're just an unknown number of iterations away from main battle tank armor with the mass and density of Styrofoam, and for precisely the same reasons.