The Proton Pack is a fictional piece of nuclear accelerative machinery created by the Ghostbusters. It is their primary tool in the 1984 Ghostbusters film for "busting" ghosts. It has a hand-held wand ("Proton Gun" or particle thrower) connected to a backpack-sized particle accelerator. It fires a proton stream that polarizes with the negatively charged energy of a ghost allowing it to be held in the stream while active. The proton packs' particle throwers were originally portrayed as wands worn on each arm.