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Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[atomic, nuclear] A physicist and mathematician from Germany. Hans Geiger is world renowned for his device development for the detection of ionizing radiation in 1909 (Geiger counter), in particular emitted from radio-active isotopes, which can prove harmful to human biology. In the joint effort with Ernest Marsden (1889–1970) in 1909, the Geiger–Marsden experiment provided the evidence for the existence of the atomic nucleus (see Figure G.28).
Evolution of Rutherford’s ion beam science to applied research activities at GNS Science
Published in Journal of the Royal Society of New Zealand, 2021
John V. Kennedy, William Joseph Trompetter, Peter P. Murmu, Jerome Leveneur, Prasanth Gupta, Holger Fiedler, Fang Fang, John Futter, Chris Purcell
The New Zealand Department of Scientific and Industrial Research (DSIR) was founded in 1926 by Ernest Marsden after calls from Ernest Rutherford for the New Zealand government to support education and research (Atkison 1976). Ernest Marsden was a former Rutherford student who conducted the famous Geiger–Marsden experiment, also called the gold foil experiment, together with Hans Geiger under Rutherford's supervision. Marden came to New Zealand in 1915 on Rutherford’s recommendation to be a Professor of Physics at Victoria University in Wellington and then the 1st director of DSIR in 1926. During this time, he championed nuclear science and technology in New Zealand leading to isotope and nuclear physics research activities starting within the Chemistry Division and the Physics & Engineering Laboratory of DSIR. In 1959, the nuclear science teams were consolidated into the Institute of Nuclear Sciences (INS) located at Gracefield in Lower Hutt as a new division of the DSIR with T.A. Rafter as the 1st director. In 1992 the INS group became part of the Institute of Geological and Nuclear Sciences when the crown research institutes (CRI) were formed and was later branded as GNS Science. As the first major research tool, a 3.7 meter 3MV single-ended Van de Graaff accelerator from High Voltage was acquired and commissioned in 1966 (Atkison 1976; Priestly 2012). This machine has been modified and upgraded over the years produces single charged positive ion beams of hydrogen (1H+), deuterium (2H+) and helium (4He+) for IBA. Inside the machine, the high voltage terminal is charged via a belt-based system and powerful electric fields accelerate and focus a continuous stream of charged particles (ion beam). An analysing magnet allows the selection of specific ion species with well-defined ion energy to enter one of the two beam lines used for broad beam and microprobe ion beam analysis experiments (Purcell 1987). Guided by beam optic components, the ion beam is shot onto targets to produce scattered particles and generate reaction products that are used for IBA (Markwitz and Kennedy 2005).