Beta radiation is the radiation that occurs when an electron is emitted from the nucleus of a radioactive atom. It can be caused by nuclear fission, such as that which results from the detonation of an atomic bomb.
After Quark, Rom, and Nog were accidentally transported to Earth, the year 1947, through a time warp, they quickly discovered that thier universal translators were not functioning. Upon learning that the Humans of that era were experimenting with atomic explosives, Rom was able to deduce that the beta radiation created as a byproduct of the explosions was the cause of the interference. Later, Rom was able to harness the beta radiation from a nuclear explosion to trigger a cascade reaction in kemacite stored in their shuttle. This caused a temporal surge in the subspace continuum, recreating the time warp and returning them to their own time. (DS9: "Little Green Men")