Ernst Ruska

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Berlin memorial plaque on the house, Falkenried 7, in Berlin-Dahlem
Ernst Ruskas electron microscope, 1933, replica from 1980
Memorial plaque , Ernst-Ruska-Ufer, in Berlin-Adlershof
The ÜM100 microscope, built by Ernst Ruska at Siemens in 1949, in the foyer of the Ernst Ruska building of the Technical University of Berlin
Gravestone for Ernst & Helmut Ruska at the forest cemetery in Zehlendorf

Ernst August Friedrich Ruska (born December 25, 1906 in Heidelberg , † May 27, 1988 in Berlin ) was a German electrical engineer and 1934 inventor of the electron microscope and professor at the Free University of Berlin . He received the Nobel Prize in Physics in 1986 .


Ernst Ruska was the son of Julius Ruska (1867–1949), orientalist, and Elisabeth Ruska, b. Merx, (1874–1945) born. His brother was the doctor Helmut Ruska (1908–1973).

Ruska attended the Kurfürst-Friedrich-Gymnasium in Heidelberg, studied electrical engineering at the Technical University of Munich from 1925 , at the TH Berlin from 1927 and received his doctorate in August 1933 on a magnetic lens for the electron microscope . He then worked in the development department of Berliner Fernseh AG. From February 1937 he and Bodo von Borries led the industrial development of electron microscopy at Siemens & Halske AG in Berlin . In 1944 he completed his habilitation at the TH Berlin . After the war he rebuilt the laboratory for electron optics at Siemens and in 1949 took over the department for electron microscopy at the Fritz Haber Institute of the Max Planck Society in Berlin-Dahlem, which in 1955 became its own institute (Institute for Electron Microscopy at the Fritz- Haber Institute), at the same time he became a Scientific Member of the Max Planck Society. In 1949 he was also appointed professor at the Free University of Berlin , from 1959 he also taught at the TU Berlin . The old building of the physical faculty of the TU Berlin is named after Ernst Ruska: Ernst-Ruska-Gebäude (ER).

Ernst Ruska was buried next to his brother Helmut Ruska in the forest cemetery (grave site Dept. XX-AW 51) in Berlin-Zehlendorf . His grave has been dedicated to the city of Berlin as an honorary grave since 2018 .


Ruska is considered one of the pioneers of electron microscopy . On March 9, 1931, he and Max Knoll succeeded in using magnetic lenses to achieve the first two-stage electron-optical magnification and thus to implement the basic technical principle of the electron microscope. It was based on the fact that magnetic fields can deflect electrons because of their charge and that electron beams can be bundled and focused in the same way as light beams through lenses and was called "super microscope" at the time. Since the wavelengths of the electrons are considerably shorter than those of light, a much better resolution is possible with an electron microscope than with an optical microscope .

Ruska exceeded the resolution limit of light with another prototype in December 1933 at 12,000 times magnification. Together with his brother-in-law, the engineer Bodo von Borries , he further developed the device so that it could be mass-produced from 1938/39.


Ernst Ruska was elected as a member of the German Academy of Natural Scientists Leopoldina - National Academy of Sciences , and was awarded numerous prizes and honorary memberships in scientific societies.

Publications (selection)

  • E. Ruska: About a calculation method of the cathode ray oscillograph on the basis of the experimentally found dependence of the writing spot diameter on the position of the concentrating coil . Student thesis at the Technical University of Berlin, Chair for High Voltage Technology, submitted on May 10, 1929
  • E. Ruska: Investigation of electrostatic collecting devices as a replacement for the magnetic concentrating coils in the cathode ray oscillograph . Diploma thesis, Technical University of Berlin, Chair for High Voltage Technology, submitted on December 23, 1930
  • E. Ruska and M. Knoll: The magnetic collecting coil for fast electron beams . In: Z. techn. Physics . Volume 12, 1931, pp. 389-400 and 448. Received on April 28, 1931
  • M. Knoll and E. Ruska: The electron microscope . In: Journal of Physics . Volume 78, 1932 pp. 318-339, received on June 16, 1932
  • E. Ruska: The Electron Microscope as Ultra-Microscope . In: Research and Progress . Volume 1, January 1935, pp. 18-19
  • E. Ruska: About building an electron-optical bank for experiments and demonstrations . In: Z. wiss. Microscopy . Volume 60, 1952, pp. 317-328
  • E. Ruska: Memories of the beginnings of electron microscopy . Festschrift Award of the Paul Ehrlich and Ludwig Darmstaedter Prize 1970, Issue 66, pp. 19–34. Gustav Fischer publishing house, Stuttgart
  • E. Ruska: The emergence of the electron microscope and electron microscopy . Nobel Lecture. In: Physical sheets . Volume 43, 1987, pp. 271-281 and Rev. Mod. Physics, respectively . Vol. 59, 1987, pp. 627-638

See also


Web links

Commons : Ernst Ruska  - collection of pictures, videos and audio files

Individual evidence

  1. Campus map of the TU Berlin (PDF; 2.1 MB)
  2. ^ Calendar sheet Deutsche Welle, March 9th, August 9th, 2006
  3. Ernst Ruska Prize of the German Society for Electron Microscopy (; Retrieved July 14, 2011
  4. Press release Forschungszentrum Jülich May 18, 2006