So I heard a little rumor that Beta decays in certain isotopes release an electron at "ultrarelativistic" speeds. I also heard a rumor that Z bosons can be created temporarily by a positron annihilating an electron when the two collide. My question is, can one place two highly radioactive metals into a single pile, and expect to get at least some Z bosons from this oppositely-charged radioactivity? If yes, how much can we expect to get? A plausible method of achieving this is to bring enriched 234m-Protactinium into proximity with a heavy isotope of Samarium (143 or such). Samarium (Sm) is used in medicine, and Protactinium (Pa) can be isolated from uranium enrichment processes. Obviously, a whole library of various isotopes could be mixed and matched here, but in particular we need two isotopes, one producing Beta minus, and the other Beta plus, such that the speeds of the emitted radiative particles are very high. I have no idea which two are best to couple together, because of various factors. One, it is difficult to find the energy emission spectrum of isotopes. And even if it were easy, this doesn't tell me whether these short-lived isotopes can be collected into large amounts or only exist in a lab.