A steady beam of alpha particles (q = + 2e) traveling with constant kinetic energy 18 MeV carries a current of 0.30 µA.
(a) If the beam is directed perpendicular to a plane surface, compute how many alpha particles strike the surface in 3.0 second?
(b) At any instant, how many alpha particles are there in a given 20 centimeter length of the beam?
(c) Find through what potential difference was it necessary to accelerate each alpha particle from rest to bring it to an energy of 18 MeV?