I'm completely out of my depth here, but couldn't we develop some kind of force field to do this? I'm thinking something along the lines of a Faraday cage, but for the GCRs.
Is anyone researching this line of thought?
A magnetic field (Van Allen belt, or analog on other bodies) deflects lighter charged particles better than heavier ones (with a greater mass-to-charge ration). E.g. - helium ions (alpha particles) vs iron nuclei as mentioned in the article.
Otherwise, pure mass over your head is the best defense.
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.