In 1968, US Air Force Captain Nathaniel Adam was framed for treason, and setenced to death by his superior General Wade Eiling, who may have had a hand in the frame up. Fortunately, an opprotunity for freedom came in the form of volunteering for a military test, involving testing the durability of an alien space ship's metal. Exposed to the energy of a nuclear bomb, Nate was believed to have died, but the energy, combined with the extraterristrial metal, hurled him eighteen years into the future. With the metal megred to his skin, and atomic energy flowing thru his body, Nate became the superhero known as Captain Atom. Blackmailed into working for the government, Cap was later freed from this forced work thru later events, and has since become a repeat member of the Justice League
Due to his link to the Quantum Field, Captain Atom has super strength and super speed on par with Superman, near invulernability, flight, energy absorption and projection, techno-interference, time-travel, and atomic transmutation.
If Captain Atom absorbs too much energy, he will either be flown far into the future or explode like an atomic bomb