(meteorobs) Meteorite pix

[stange]

Is it thought that meteroids entering the solar system from a travel through 
the galaxy would not be radioactive from encountering primarily higher 
energy cosmic rays, but those meteoroids formed (within) the solar system 
and coming from orbits within the asteroid belt would be radioactive from 
isotope formation due to planetary magnetic focussing of lower energy cosmic 
rays?

Is my understanding correct that rates and velocities of cosmic radiation 
that cause isotope formation, would be dramatically different in these two 
situations?