Jacques Yvon

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Jacques Yvon (born April 26, 1903 in Angoulême ; † September 28, 1979 ) was a French theoretical physicist who also played an important role in French nuclear engineering.


Yvon studied from 1922 at the École normal supérieure (Paris) , received his doctorate in 1937 and was from 1938 maître de conférences at the University of Strasbourg . In 1943 he was deported to Germany and after returning in 1946 was a professor at the University of Strasbourg. From 1949 he was at the CEA (which he advised on questions of the theory of neutron diffusion from 1948) at the invitation of Jules Guéron and headed the theoretical department there (Service de physique mathématique, his successor was Jules Horowitz , followed by Claude Bloch and Jean Bussac ) and from 1952 the department for reactor research (Département d 'études de piles, DEP) as successor to Lew Kowarski and from 1959 to 1962 director of the physics and reactors department. 1962 to 1973 he was professor for theoretical physics at the Sorbonne .

He was also involved in the development of the French atomic bomb as a consultant in the 1960s.

He mainly dealt with statistical mechanics. In 1935 he introduced a distribution function in the N-body problem of statistical mechanics and is therefore one of the authors of the BBGKY hierarchy of equations for determining the N-particle distribution function. The others are Max Born , Herbert S. Green , Nikolai Nikolajewitsch Bogoljubow and John G. Kirkwood with works published around 1946 (BBGKY stands for their first letter). In theoretical reactor physics , too , he tried to replace the semi-empirical approach that dominated the American physicists around Enrico Fermi and Eugene Wigner with a more precise approach based on the Boltzmann equation for neutron diffusion.

He was one of the pioneers of nuclear energy in France (theory of nuclear reactors, neutron physics), was High Commissioner for Atomic Energy from 1970 to 1975 and a member of the French Atomic Energy Commission (PEON, Commission pour la Production d'Électricité d'Origine Nucléaire).

In 1952 he received the Prix ​​Félix Robin .


  • Œuvre scientifique, 1985 (Ed. A. Decoster et al.)
  • Calcul du régime critique d'une pile cylindrique munie d'un réflecteur, Journal de Physique et le Radium, Volume 12, May 1951
  • Les corrélations et l'entropie en mécanique statistique classique, Dunod 1966
  • Une méthode d'étude des corrélations dans les fluides quantiques en équilibre, Nuclear Physics, Volume 4, 1957
  • La diffusion macroscopique des neutrons, une méthode d'approximation, Journal of Nuclear Energy, Volume 4, 1957
  • La diffusion d'un projectile par un système complexe lié, Nuclear Physics, Volume 5, 1958

Web links

Individual evidence

  1. Graduated from École Polytechnique and from 1951 in the Service théoretique in Saclay, which he headed from 1962 to 1970
  2. See the short biography from Foasso's dissertation in the web links
  3. Yvon, La théorie statistique des fluides et l'équation d'état, Actualités scientifiques et industrielles, Hermann, No. 203, 1935