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Geiger,
Hans German physicist Born: Neustadt-an-der-Haardt, Rhineland, September 30, 1882 Died: Berlin, September 24, 1945 | |||||||||
Avogadro Becquerel Bohr Doppler Einstein Geiger Heisenberg Hertz Kirchhoff Planck Roentgen Rutherford Schrodinger |
Geiger assisted Rutherford in his experiments with alpha particle scattering, but at the beginning of World War I, he returned to Germany to serve in the artillery. In 1913, he invented a device for detecting energetic subatomic particles, which is today known as the "Geiger counter". This device consists of a cylinder containing a gas with a high electric potential that falls just short of overcoming the electrical resistance of the gas. When an energised sub-atomic particle enters the device, it ionises one of the gas particles, causing it to be drawn towards the cathode. As the ion is attracted toward the cathode it collides with other gas particles, ionising them in turn, and creating a "chain" reaction of ionisation. This ionisation process creates a momentary electrical current which is recorded as a clicking sound. These clicks are in fact used to count the particles as they enter the device, a greater volume of clicks indicating higher radiation. Geiger was appointed a Professor of Physics at the University of Kiel in 1925. He moved to the University of Tubingen in 1929. | |||||||||
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