|
Sci Tech
Pioneer in nuclear instrumentation
HANS GEIGER was born in Neustadt, (Germany) on September 30, 1882, the son of a professor of philology. He passed his `Abitur' (matriculation) at the Erlangen Gymnasium (1901). He studied physics at the Universities of Erlangen and Munich. In 1904, he began research under Eilhard Wiedemann, gaining a doctorate in 1906 for his thesis on electrical discharges through gases.
Working with Rutherford Geiger then took a position in England, as an assistant to Arthur Schuster at the University of Manchester. Rutherford who succeeded Schuster in 1907, persuaded Geiger to continue at Manchester and apply his knowledge of gaseous ionisation to the study of radioactive disintegration.
In 1908 Geiger and Rutherford investigated the nature and charge of the alpha particle. They devised an electrical technique in order to count the individual alpha particles and compare the results with those obtained by the scintillation technique.
These experiments resulted in a proto-type counter for alpha particles; each causing a gas to ionise and conduct a current whose passage was registered by a sensitive electrometer. Geiger and Marsden demonstrated (1909) the large deflection of alpha particles by gold leaf. This discovery led to Rutherford's theory of the atom and gave confirmatory evidence showing that the nuclear charge was about half the atomic weight. On returning from England in October 1912, Geiger started his career as director of the new lab for radium research at the Physikhalisch Technische Reichsanstalt, Berlin.
He saw active service as infantry officer during World War I and returned in 1918 to his academic post.
In 1925 Geiger took his first teaching position at the University of Kiel. He improved further the sensitivity of his counter: and with Walther Muller, he perfected the modern form of the apparatus. The gradual production of these practical counters from 1928 marks the introduction of modern electrical devices into radiation research. The Geiger counter, compact and portable, met a variety of laboratory requirements in particle detection and counting. It was employed (1925) to confirm the `Compton effect', making simultaneously observations on the scattered radiation and the recoil electron. In October 1926, he accepted an invitation from the Tuebuigen University, where he served as professor of physics till 1936. He then moved to the Technical University in Berlin and directed a research group studying artificial radioactivity and the products of nuclear fission. The counter was used for counting in 1913 beta particles by James Chadovick and for detecting cosmic ray showers. Geiger was editor of Journal of Physics for 8 years (1937- 1944).
Geiger was a perfectionist, always trying to obtain the most from both his students and his experiments. He was a talented lecturer and enjoyed the admiration of his colleagues.He received the Hughes Medal of the Royal Society (1929) and the Duddell Medal from the London Physical Society (1938) for his contributions to scientific instrumentation.
Dogged by illness during World War II he lost his home and possessions in the occupation of June 1945. He was forced to flee to Potsdam, where he died on September 25, 1945. (The Dictionary of Scientific Biography, Vol. V).
R. Parthasarathy
Send this article to Friends by
E-Mail
Sci Tech
|
