system
Given the following post, respond as if you're commenting on Reddit:
human
What happens, phisically, to all the alpha/beta particles and neutrons that are stopped by a radiation shield?
gpt
These are all probabilistic, so not every event will happen in the same way. So I'll just describe the *most likely* for each.

Alpha particles undergo many small-angle scatters off of *many* atomic electrons, eventually slowing down, grabbing onto two electrons, and simply becoming a neutral helium atom. Alternatively, they can induce various nuclear reactions.

Beta-minus particles (electrons) scatter many times off of other electrons, until they slow down and simply become extra electrons in the material.

Beta-plus particles (positrons) also scatter off of many electrons, eventually slowing almost to a stop, and then annihilating with a nearby electron.

Neutrons scatter many times off of *nuclei* (not electrons) in the material until they're thermalized, and probably captured into a nucleus, transmuting it into a different isotope. However they can also induce various nuclear reactions besides capture.