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Francis Perrin: A Pioneer in Atomic Research

by Jean Chabrier
FRANCIS Perrin was bom in Paris in 1901. He was the son of Jean Perrin, winner of the Nobel Prize tn physics in 1926. With such a father, from his childhood he frequented Marie Curie, the Joliot-Curies and all the greatest scientific minds of the century.
At the age of 17. he won a place at the prestigious 'Ecole Normale" school for teachers, where he was the youngest student, and. following in his father's footsteps he gained his "aggregation" teaching qualtfi , cation and then his doctorate in science (physics and math cmatics) at the age of 27. In 1933, he was appointed senior lecturer and then professor at the Sorbonne in 1935 at the age of 34.
Surrounded mostly by leftwingers (his father was a minister In the Popular Front), he was a socialist militant and a down and out atheist, but he soon gave up politics. However, tn the 30s. with his father, he was part of the very closed group of French atomic scientists. He took part in the research carried out by this group of physicists who revolved around Frederic Joliot-Curle in the cramped precincts of the laboratories of the Sorbonne and the College de France.
The close cohesion between these researchers and their families should be noted, and to such an extent that many of them met up again on holiday in the same part of Brittany. In Palmpol. He thus knew Marie Curie's two daughters and married P Augicrs daughter.
In 1939, together with the team, he drew up the texts of five fundamental patents covering all kinds of applica tlons for nuclear energy, from the reactor to the bomb. It was he who, In May 1939, discovered the notion of "critical mass", that is to say the amount of .fissile matter necessary and sufficient to start a chain reaction. He humorously recounts how all this took place in a Jules Verne-like atmosphere and how, ecstatic over the enor-mous power that they could create, they imagined digging a canal to irrigate the Sahara.
Watchfulness
In 1940, several of these scientists went into exile both out of conviction and. also not
to have to disclose their secrets to the Nazi, freely or by force. In the United State.. Francis Perrin held the chair of physic. at Columbia Untver.ity. Then he was appointed to the Consultative Assembly tn Algiers, by General de Gaulle, in 1946. he obtained the chair of professor of atomic and molecular physics at the College de France.
In 1951. he took over from Frederic Joliot-Curle as the High Commluloner for atomic energy, a post he was to hold until 1971. He thu. con-
true. He very well knew the demons that he had con trlbutcd to taming and was scrupulously watchful It is no doubt partly thanks to him that France is one of the rare atomic powers which has not
it. nuclear power stations, making her the largest producer of civil nuclear energy.
If he has acquired International renown as an atomic physicist, it should also be pointed out that he has dtsttn-CIs bed hi nwc If in many other ids such as the Ouercscenee
tributed to setting up Euratom, to developing the first nuclear reactors and then to the creations of nuclear power sta= lions such as Pierrclattc and research centres such as Saclay and Marcoulc.
' This shy, gentle and affable man, with his clear eyes, who was a philosopher tn his free lime, believed in the peaceful application of the atom. He was one of the rare pioneers to have seen his dream come
of solutions, the duration of elementary light emissions, the Brownian rotation movement of spherical and ellipsoidal particles, the dielectric dispersion of solutions of large molecults. the diffusion of light in an opalescent environment. etc ...
His death, at the age of 91. marks the disappearance of one of the last atomic physicists of the heroic era.
— L' Actualltc En France