Francis Perrin (17 August 1901 – 4 July 1992) was a French physicist, the son of Nobel prize-winning physicist Jean Perrin.
Francis Perrin was born in Paris and attended École Normale Supérieure in Paris. In 1928 he obtained a doctorate in mathematical sciences from the faculté des sciences of Paris, based upon a thesis on Brownian motion and became a faculty member of Collège de France. In 1933, in connection with the neutrino, Francis Perrin estimated that “the mass must be null—or at least small compared to the mass of the electron”. Subsequently he worked at the Collège de France on the fission of uranium. With Frédéric Joliot and his group, he established in 1939 the possibility of nuclear chain reactions and nuclear energy production.
He was professor at the Collège de France in the chair of Atomic and Molecular Physics from 1946 to 1972. He was the French high-commissioner for atomic energy from 1951 to 1970. In 1972, he discovered the Oklo natural reactor.
Named High-Commissioner of the Commissariat à l'énergie atomique (Atomic Energy Commission, CEA) in 1951—to replace Frédéric Joliot-Curie dismissed because he was opposed to military research—, Francis Perrin joined a lobby of about a dozen people, composed of politicians like Chaban-Delmas, Bourguès-Maunoury and Félix Gaillard, of military officers, like the generals Ailleret, Gallois, and Crépin, of technocrats like Pierre Guillaumat and Raoul Dautry or of scientists like Yves Rocard and Bertrand Goldschmidt, who revealed themselves to be extremely effective. This lobby imposed on successive governments of the Fourth Republic an intensive research program to permit France to deploy nuclear weapons without any real political control from outside France. Secret departments were made up within the CEA to implement this policy as of 1954. General Charles de Gaulle was informed of the work during his "Crossing of the Desert" (1953/58), in particular by Chaban-Delmas. When de Gaulle returned to power in 1958, the progress of the work was such that the date of the first nuclear test was already fixed at 1960.