Andrei Sakharov — Biographical Profile

Andrei Dmitrievich Sakharov was a Soviet theoretical physicist whose 1950–51 papers with his mentor Igor Tamm sketched the magnetic-thermonuclear reactor — the original tokamak concept. He proposed using a strong toroidal magnetic field combined with a poloidal field induced by current flowing through the plasma itself, producing the helical field-line geometry that confines a fusion-grade plasma. The architecture was declassified at the 1958 Atoms for Peace conference in Geneva and rapidly became the global benchmark for magnetic confinement research. Sakharov also played a central role in the Soviet thermonuclear weapons program and originated the concept of inertial confinement fusion driven by an external energy pulse. He is equally remembered as a human-rights advocate; his 1968 essay on intellectual freedom led to his internal exile and his 1975 Nobel Peace Prize. His scientific legacy in fusion is foundational: the tokamak remains, seventy years later, the architecture of the world's largest fusion projects.