Max knoll and ernst ruska contribution

Physicist Date of Birth: 25.12.1906 Country: Germany

Content:

1. Biography of Ernst Ruska
2. Invention of the Electron Microscope
3. Development and Applications of Electron Microscopy
4. Later Career and Honors

Biography of Ernst Ruska

Early Life and Education

Ernst August Ruska, a German physicist, was born in Heidelberg and was the fifth child of Julius Ferdinand Ruska, an orientalist professor, and Elizabeth (née Merke) Ruska. In 1925, Ruska started studying physics at the Technical University of Munich, and in 1927, he transferred to the Technical University of Berlin. He completed his internship at Siemens & Halske in Berlin and Brown-Boveri in Mannheim. After obtaining his engineering degree in 1931 from the Technical University of Berlin, Ruska defended his doctoral dissertation in electrical engineering under the guidance of Max Knoll. During his research, Ruska made a discovery that eventually led to the invention of the electron microscope.

Invention of the Electron Microscope

The invention of the electron microscope was driven by the limitations of the conventional optical microscope, which had a resolution limited by the wavelength of visible light. In the mid-1920s, it was known that electromagnetic radiation, such as light, behaved like particles. French physicist Louis de Broglie hypothesized in 1924 that particles, such as electrons, also had wave properties. Clinton J. Davisson and Lester Germer experimentally confirmed the wave properties of electrons in 1927. Building on this knowledge, Ruska made significant progress in the late 1920s towards developing the electron microscope. He discovered that a magnetic coil could act as a lens for electrons and built magnetic lenses with a short focal length, enabling the imaging of objects irradiated with electrons.

Development and Applications of Electron Microscopy

In 1931, Ruska and Knoll developed the first electron microscope, consisting of two sequentially arranged magnetic lenses. While less powerful than modern optical microscopes with only 15x magnification, this device established the fundamental principle of electron microscopy. In 1933, Ruska constructed an electron microscope with a resolution capable of detecting details as small as 500 angstroms, allowing researchers to study objects ten times smaller than what powerful optical microscopes could resolve. Ruska's invention revolutionized various scientific fields, particularly biology and medicine, by enabling the study of metals, viruses, protein molecules, and other biological structures.

Ruska's electron microscope stimulated the development of other types of electron microscopes, including the scanning electron microscope, which became one of the most important advancements in electron microscopy. In 1986, Ruska was awarded half of the Nobel Prize in Physics "for his fundamental work in electron optics and for the design of the first electron microscope." The other half of the prize was awarded to Gerd Binnig and Heinrich Rohrer for their contributions to the invention of the scanning tunneling microscope.

Later Career and Honors

After completing his doctoral dissertation in 1933, Ruska joined a television company in Berlin, where he focused on improving television tube manufacturing technology. In 1937, he became an electrical engineer at Siemens and participated in the development of the first commercial electron microscope, which was introduced to the market in 1939 with a resolution of 100 angstroms. Ruska held various positions throughout his career, including director of the Electron Microscopy Institute at the Max Planck Society from 1957 to his retirement in 1972. He also served as a private lecturer at the Technical University of Berlin and received honorary doctorates from universities in Kiev, Modena, Toronto, and the Free University of Berlin.

In addition to the Nobel Prize, Ruska received numerous awards and honors for his contributions to the field of electron microscopy. These included the Senckenberg Prize from the University of Frankfurt in 1939, the Leibniz Silver Medal from the Prussian Academy of Sciences in 1941, the Lasker Award from the American Health Association in 1960, the Duddell Medal and Prize from the London Physical Society in 1975, and the Kotenius Medal from the German Academy of Sciences "Leopoldina" in 1975.

Ernst Ruska passed away on May 27, 1988, leaving behind a lasting legacy in the field of electron optics and microscopy.