thermonuclear weapons would have been seen either as a clever feint, or as the manifestation of stupidity. In both cases, the reaction would have been the same – avoid the trap and immediately take advantage of the enemy's stupidity." Sakharov never felt that by creating nuclear weapons he had "known sin", in Oppenheimer's expression. He later wrote: Support for peaceful use of nuclear technology In 1950 he proposed an idea for a controlled nuclear fusion reactor, the tokamak, which is still the basis for the majority of work in the area. Sakharov, in association with Tamm, proposed confining extremely hot ionized plasma by torus shaped magnetic fields for controlling thermonuclear fusion that led to the development of the tokamak device. Magneto-implosive generators In 1951 he invented and tested the first explosively pumped flux compression generators, compressing magnetic fields by explosives. He called these devices MK (for MagnetoKumulative) generators. The radial MK-1 produced a pulsed magnetic field of 25 megagauss (2500 teslas). The resulting helical MK-2 generated 1000 million amperes in 1953. Sakharov then tested a MK-driven "plasma cannon" where a small aluminum ring was vaporized by huge eddy currents into a stable, self-confined toroidal plasmoid and was accelerated to 100 km/s. Sakharov later suggested replacing the copper coil in MK generators with a large superconductor solenoid to magnetically compress and focus underground nuclear explosions into a shaped charge effect. He theorized this could focus 1023 protons per second on a 1 mm2 surface. Particle physics and cosmology After 1965 Sakharov returned to fundamental science and began working on particle physics and physical cosmology. He tried to explain the baryon asymmetry of the universe; in that regard, he was the first to give a theoretical motivation for proton decay. Proton decay was suggested by Wigner in 1949 and 1952. Proton decay experiments had been performed since 1954 already. Sakharov was the first to consider CPT-symmetric events occurring before the Big Bang:We can visualize that neutral spinless maximons (or photons) are produced at ''t'' < 0 from contracting matter having an excess of antiquarks, that they pass "one through the other" at the instant ''t'' = 0 when the density is infinite, and decay with an excess of quarks when ''t'' > 0, realizing total CPT symmetry of the universe. All the phenomena at t < 0 are assumed in this hypothesis to be CPT reflections of the phenomena at t >