24365d85ca In 1908 Hans Geiger, under the supervision of Ernest Rutherford at the Victoria University of Manchester (now the University of Manchester), developed an experimental technique for detecting alpha particles that would later be used in the Geiger-Mller tube.[6] This early counter was only capable of detecting alpha particles and was part of a larger experimental apparatus. Consequently, a typical design for low energy photon detection for these is a long tube with a thin wall or with an end window. The original detection principle was discovered in 1908 at the Cavendish laboratory, but it was not until the development of the Geiger-Mller tube in 1928 that the Geiger-Mller counter became a practical instrument. This creates an alpha particle inside the detector and thus neutrons can be counted. 31, pages 617618. However, efficiency is generally low due to the poor interaction of gamma rays compared with alpha and beta particles. 81, no. However, for low energy photons there is greater gas interaction and the direct gas ionisation effect increases.
There are also hybrid instruments which have a separate probe for particle detection and a gamma detection tube within the electronics module. Limitations[edit]. Rutherford and H. (1929) "Demonstration des Elektronenzhlrohrs" (Demonstration of the electron counting tube), Physikalische Zeitschrift, 30: 523 ff. For high energy gamma it largely relies on interaction of the photon radiation with the tube wall material, usually 12mm of chrome steel on a "thick-walled" tube, to produce electrons within the wall which can enter and ionize the fill gas.[2] This is necessary as the low pressure gas in the tube has little interaction with high energy gamma photons. Media related to Geiger counters at Wikimedia Commons. Laboratory use of a G-M counter with end window probe to measure beta radiation from a radioactive source . Low energy photon radiation such as low energy X rays or gamma rays interacts better with the fill gas.
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