Andrei Sakharov : biography
Support for peaceful use of nuclear technology
In 1950 he also 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 Igor 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.
Efforts to improve nuclear reactor technology
In 1951 he invented and tested the first explosively pumped flux compression generators,A.D. Sakharov: "Magnetoimplosive generators", UFN 88:4, 725–734 (1966); Sov. Phys. Uspekhi 9: 294–299 (1966). compressing magnetic fields by explosives. He called these devices MC or MK (for magnetocumulative) generators. The radial MK-1 produced a pulsed magnetic field of 25 megagauss (2500 teslas). The following helical MK-2 generated 100 million amperes in 1953.
Sakharov then tested a MK-driven "plasma cannon" where a small aluminium ring was vaporized by huge eddy currents into a stable, self-confined toroidal plasmoid and was accelerated to 100 km/s. Sakharov later suggested to replace the copper coil in MK generators by a big 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, then envisaged making two such beams collide. But it is not known if any experiment based on this idea has been ever achieved.
Research and physics
After 1965 Sakharov returned to fundamental science and began working on particle physics and cosmology.A.D. Sakharov: "Expanding Universe and the Appearance of a Nonuniform Distribution of Matter", ZhETF 49: 345–358 (1965); translation in JETP Lett. 22: 241–249 (1966) A.D. Sakharov: , Pisma Zh. Eksp. Teor. Fiz. 5: 32–35 (1967); translation in JETP Lett. 5: 24–27 (1967) A.D. Sakharov: , Pisma Zh. Eksp. Teor. Fiz. 5: 36–39 (1967); translation in JETP Lett. 5: 27–30 (1967) A.D. Sakharov: "Antiquarks in the Universe" in "Problems in theoretical physics", dedicated to the 30th anniversary of N.N. Bogolyubov, Nauka, Moscou, pp. 35–44, 1969 A.D. Sakharov and I.D. Novikov: "A multisheet Cosmological model" Preprint Institute of Applied Mathematics, Moscow, 1970 A.D. Sakharov: "Topological structure of elementary particles and CPT asymmetry" in "Problems in theoretical physics", dedicated to the memory of I.E. Tamm, Nauka, Moscow, pp. 243–247, 1972 A.D. Sakharov: "Baryonic asymmetry of the Universe", ZhETF 76: 1172–1181 (1979); translation in JETP Lett. 49: 594–599 (1979) A.D. Sakharov: "Cosmological model of the Universe with a time vector inversion". ZhETF 79: 689–693 (1980); translation in JETP Lett. 52: 349–351 (1980)
He especially tried to explain the baryon asymmetry of the universe, being the first scientist to introduce two universes called "sheets", linked by the Big Bang. Sakharov achieved there a complete CPT symmetry since the second sheet is enantiomorph (P-symmetry), has an opposite arrow of time (T-symmetry) and is mainly populated by antimatter (C-symmetry) because of an opposite CP-violation. In this model the two universes do not interact, except via local matter accumulation whose density and pressure would become high enough to connect the two sheets through a bridge without spacetime between them, but with geodesics continuity beyond the radius limit allowing an exchange of matter. Sakharov called such singularities a collapse and an anticollapse, which are an alternative to the couple black hole and white hole in the wormhole theory. Sakharov also proposed the idea of induced gravity as an alternative theory of quantum gravity.
Turn to activism
From the late 1950s Sakharov had become concerned about the moral and political implications of his work. Politically active during the 1960s, Sakharov was against nuclear proliferation. Pushing for the end of atmospheric tests, he played a role in the 1963 Partial Test Ban Treaty, signed in Moscow.