Enrico Fermi

Enrico Fermi ( born September 29, 1901 in Rome, Italy, † November 28, 1954 in Chicago, USA ) was one of the most important nuclear physicist of the 20th century. In 1938 he was awarded the Nobel Prize for Physics.


At the age of 17 he began to study physics at the University of Pisa, where he graduated in 1922 with a thesis on X-ray scattering in crystals. 1923, Fermi thanks to a grant several months research stay in Gottingen with Max Born. Göttingen was at that time the leading center of theoretical physics, where many essential work for quantum mechanics emerged. In 1924 he spent several months in Holland with Paul Ehrenfest, also a co-founder of quantum mechanics. After that Fermi was first appointed as professor of mathematics to Florence. Two years later he went as professor of theoretical physics to Rome. Here is his theoretical work on solid state physics and quantum statistics emerged ( Fermi -Dirac statistics for fermions, Fermi's Golden Rule, Fermi surface, Fermi resonance, Thomas - Fermi theory of the atom ). In Rome, was built around Fermi a very active group of theoretical and experimental physicists. Your belonged to Gian- Carlo Wick, Ugo Fano, Giovanni Gentile, Giulio Racah, Ettore Majorana and the experimenters Rasetti Franco, Giuseppe Cocconi, Emilio Segrè, Edoardo Amaldi, Bruno Pontecorvo and.

Inspired by the discovery of the neutron by James Chadwick in 1932 and by the detection of nuclear transformations after irradiation with alpha particles by Irène and Frederic Joliot- Curie to Fermi turned in 1934 to the Experimental Physics. His seminal discovery was that nuclear transformation processes run much more efficiently through neutron radiation. A further improvement of the yield obtained when the neutrons are strongly braked (thermal neutrons). 1934 Fermi published his theory of beta decay ( " Fermi interaction "). As early as 1933 he had coined the term neutrino of one of the particles involved in the beta -decay, whose existence had been three years earlier postulated by Wolfgang Pauli.

Neutron irradiation of the then heaviest known element uranium achieved Fermi and his colleagues also changes in the starting material ( different chemical behavior, altered half-lives of the emerging radiation ) and mistakenly interpreted this as the core conversion to transuranic elements ( Nature article 1934). Ida Tacke Noddack - criticized and have already pointed to the possibility of nuclear fission, which then four years later, Otto Hahn and Fritz Strassmann showed by means of chemical analytical techniques; the theoretical foundations were developed by Lise Meitner and Otto Frisch. The first transuranic could be detected only in 1942, but by a completely different synthetic procedure. 1938 Fermi received the Nobel Prize for his work in physics, although his interpretation of the neutron experiment (generation of " transuranic " ) according to current knowledge, erroneous speculation without evidence. Was exposed, with his family in the U.S. - the same year Fermi emigrated because of reprisals by the Mussolini regime, where his wife Laura - who was Jewish.

The early 1940s, Isidor Isaac Rabi and Fermi with Polycarp Kusch worked at Columbia University in New York.

He succeeded on December 2, 1942 ( 15:25 clock ) at the University of Chicago with the nuclear reactor Chicago Pile No.. 1 the first time a critical fission chain reaction, a performance that was based on the theoretical groundwork of Leo Szilard.

In summer 1944, Fermi and his family moved to Los Alamos (New Mexico ) to the secret nuclear research laboratory in the U.S.. As a consultant of Robert Oppenheimer Fermi played an important role in the development and construction of the first nuclear bombs. After the Second World War, Fermi busy again with the basic research in nuclear research center at the University of Chicago. After a trip to Europe in 1954 Fermi ill from stomach cancer, which he still died the same year.

Fermi was known for his quick assessments and its physical intuition - he was a master of the "back of the envelope" calculations ( which require no more space than the back of envelopes ). Literally are the Fermi questions ( Fermi problems ) to estimate the number of piano tuners in a city like Chicago, such as from a few data.

According to him, the electron gas is (also Fermi gas ) (see metal bond ) named, a group of elementary particles ( fermions ), the chemical element artificially produced fermium and an energy level in solids ( Fermi ). The International Atomic Energy Agency of the United States donated in his memory for the Z. with 375,000 U.S. dollars doped Enrico Fermi Award. The Fermi National Accelerator Laboratory near Chicago, is named after him and the regular courses of the International School of Physics Enrico Fermi, the Italian Physical Society and the Premio Enrico Fermi.

Fermi was a member of the Masonic Confederation. Since 1935 he was a member of the Scholars Academy Leopoldina.


  • Emilio Segrè, Franco Rasetti, Enrico Persico, Edoardo Amaldi, Herbert Anderson, CS Smith, A. Wattenberg (eds. ) Note e Memorie ( Collected works ), University of Chicago Press, Accademia dei Lincei, 2 vols 1962, 1965.
  • For the quantization of the monatomic ideal gas, Journal of Physics Vol 36, 1926, pp. 902-912 ( Fermi statistics).
  • Attempt at a theory of beta radiation, Journal of Physics Vol 88, 1934, p 161
  • Possible production of elements of atomic number 92 Greater Than, Nature Vol 133, 1934, p 898 ( Fermi mistakenly thought to have generated transuranic elements ).
  • Quantum theory of radiation, Reviews of modern physics, Vol 4, 1932, pp. 87-132.
  • About the Raman effect of carbon dioxide. Journal of Physics Vol 71, 1931, pp. 250-259 ( Fermi resonance ).
  • Experimental production of a divergent chain reaction, American Journal of physics, vol 20, 1952, S. 536 ( the Chicago reactor, reprinted in Horst welfare: 40 years of nuclear fission, University Press, 1979).
  • Nuclear physics, 1950.
  • Thermodynamics, Dover (Lecture of 1936).



After Enrico Fermi named concepts

Physical concepts:

  • The fermion, a particle type, and, derived from: the Fermi gas
  • The fermion condensate
  • Is the Fermi distribution (including Fermi level or Fermi energy and Fermi temperature)
  • Intrinsic Fermi
  • The Fermi surface for describing the energy state of electrons in a metal

Philosophical and methodological concepts:

  • The Fermi paradox to question whether we are the only intelligent beings in the universe
  • The Fermi problem for the estimation of values ​​without precise data


  • The chemical element fermium
  • The ( outdated ) Unit of length: 1 Fermi = 1 fm = 10-15 m = 1 femtometer
  • The Enrico Fermi Award for research on the development, use or control of nuclear energy
  • Fermilab ( Fermi National Accelerator Laboratory) in Illinois, United States
  • The former name of the named after him and developed by Fermilab and CERN Linux distribution Fermi Linux (now Scientific Linux )
  • The Enrico Fermi nuclear power plant in the U.S.
  • The former nuclear power plant Enrico Fermi in Italy
  • The Fermi Gamma - ray Space Telescope, a space telescope for gamma-ray astronomy
  • The Fermi architecture for graphics processing units developed by Nvidia