RUSKA (Ruska), Ernst( German physicist, Nobel Prize in Physics, 1986)
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Biography RUSKA (Ruska), Ernst
December 25, 1906, Mr.. - May 27, 1988
German physicist Ernst Ruska was born in Heidelberg and was the fifth child (of seven children), professor of orientalist Julius Ferdinand Ruski and Elizabeth (nee Merke) Ruski. In 1925, Mr.. R. began an in-depth study of physical sciences at the Munich Technical University, in 1927. joined the Technical University of Berlin. Practice was held in the companies 'Siemens und Halske' (Berlin) and 'Brown - Boveri' in Mannheim. Being in 1931. the end of the Berlin Technical University, an engineer, he was two years later obtained a doctorate in electrical engineering under Max Knoll.
While working on his thesis, P. made a discovery that eventually led to the invention of the electron microscope. The main idea of the invention pushed from the limited capacity of conventional optical microscope, the resolution limit of which - the wavelength of visible light. Visible light has a wavelength of about 5000 angstroms, or one half a million meters, the diameter of the same atom is only 1 angstrom (one ten-meter). It is impossible to build an optical microscope such power that it could consider such small objects.
By the mid 20-ies. was well known that electromagnetic radiation (eg light) has particle properties, ie. behaves as a stream of particles. In 1924, Mr.. French physicist Louis de Broglie hypothesis that particles such as electrons, in turn, have wave properties. De Broglie calculated that the higher the energy of the electron, the shorter should be the length of its wave. For example, an electron with an energy of 100 keV has a wavelength of about 0.1 angstrom, or about one-tenth the diameter of an atom. In 1927, Mr.. Clinton J. Davisson and Lester Germer of the laboratory 'Bell' experimentally confirmed the existence of the wave properties of the electron.
. Since the electron can have a wavelength of ten times smaller than the diameter of a single atom, the experimenters have to think about building a microscope, which would be used instead of light, electrons
. In the late 20-ies P. Progress was made towards the creation of an electron microscope, when he discovered that the magnetic coil can act as a lens for electrons. In addition, he managed to build a magnetic lens with short focal length so that they can be used to obtain images of the object irradiated with electrons.
The first electron microscope, developed by P. and Knoll in 1931, consisted of two consecutive magnetic lenses. When 15-fold increase in this device was much less powerful than contemporary optical microscopes, but it is possible to establish the basic principle of electron microscopy. In 1933. R. A variant electron microscope, . resolving power to detect details of the size of 500 angstroms researchers could study the details of ten times smaller, . than, . which can resolve the most powerful optical microscopes.,
. After defending his doctoral dissertation in 1933
. R. becomes a member of a television company in Berlin and is engaged in the improvement of production technology of television tubes. In 1937, Mr.. he is an engineer-electrician companies 'Siemens' participating in the development of the first commercial mass electron microscope. This device with a resolution of 100 angstroms first entered the market in 1939. Currently, there are electron microscopes that can resolve details of the size of 1 angstrom.
Developed P. the electron microscope called a translucent. When using a transmission microscope, the material under study (under the microscope placed his thin slice) bombarded with a narrow beam of electrons. Penetrating into the material, the electrons are deflected from the straight path, and their variance depends on the composition and structure of the material. Placing on the path of the electron beam photographic emulsion, the researcher receives a larger image of the material. Electron microscope R. found application in various fields of science, in t. h. the study of metals, viruses, protein molecules and other biological structures.
Invented P. translucent microscope has stimulated the development of other types of electron microscopes, the most important of which, apparently, is a scanning electron microscope. In this instrument the sample is sent sharply focused beam of electrons, and the researcher, rather than to observe the electrons that have passed through the material, observing the electrons that have undergone scattering it. Magnetic coils allow you to control the movement of the incident beam on the surface of the material as, . the capacitors control the movement of the electron beam on the surface of a television tube, . capturing variation in the distribution of scattered electrons, . researcher obtains three-dimensional image in contrast to the planar images (slice!), . obtained using a transmission electron microscope,
. Since the resolution is achieved by scanning electron microscope, lower than the resolution of a transmission microscope, these two types of electron microscopes are complementary.
In 1949, when he was the employee of the company 'Siemens', P. became assistant professor (part-time lecturer), Technical University of Berlin. In the same year he received the title of honorary professor at the Free University in Berlin. In 1954, a year before leaving the company 'Siemens', P. joins. Max Planck Society, which appointed him in 1957,. Director of the Institute of Company controlled by electron microscopy. Two years later he accepts the offer to take the post of professor of electron optics and electron microscopy at the Berlin Technical University P. continued active research in the field of electron optics and microscopy until retirement, which followed in 1972
P. was awarded half the Nobel Prize 1986. 'for fundamental work on electron optics and the creation of the first electron microscope'. The other half of the prize was awarded to Gerd Binnig and Heinrich Rohrer, for their contribution to the creation of a scanning tunneling microscope. At the presentation ceremony, the winner of the representative of the Royal Swedish Academy of Sciences said, 'The value of electron microscopy for various areas of science, particularly biology and medicine, now widely recognized. Over the past decade, electron microscopy has achieved extraordinary prosperity, there were important technical improvements and innovative schemes of electron microscopes. Opening P. can hardly be overestimated, and against the background of the importance of the first fundamental work is becoming more evident. While in the field of electron microscopy is quite a number of researchers, the contribution of P. Past them is clearly dominated by electron-optical studies and the establishment of this first electron microscope have been crucial for the subsequent development of electron microscopy '.
In 1937, Mr.. R. married Ruth Irmeli Gaygis, they have two sons and a daughter. R. died May 27, 1988
In addition to the Nobel Prize, P. awarded Zenkenberga University of Frankfurt (1939), . Leibniz silver medal of the Prussian Academy of Sciences (1941), . Lasker Award of the American Public Health Association (1960), . medals and prizes Dardella London Physical Institute (1975) and medals Koteniusa Germanskoy Academy of Natural Scientists 'Leopoldina' (1975),
. He was an honorary doctorate by the University of Kiev, Modena, Toronto and the Free University of Berlin.