An electrical method of counting the number of [alpha]-particles from radioactive substances.

London: Harrison & Sons for The Royal Society, 1908.

First edition, the invention of the Geiger counter. This device made possible the famous alpha-particle scattering experiment carried out by Geiger and Marsden which led Rutherford to the discovery of the atomic nucleus.

“In 1907 Rutherford was translated to the chair of physics in the University of Manchester. Here he found a young graduate of Erlangen, Hans Geiger, with whom he devised [in the present paper] an electrical method of counting the alpha-particles directly, the Geiger counter as it has since been generally called... This counting of atoms one by one was a great achievement” (Whittaker, History of Theories of Aether and Electricity, Vol. I, p. 7).

The detector devised by Geiger consisted of a wire in a low-pressure chamber with a voltage applied across the wire and the outside of the tube. The voltage is high enough that a current can almost, but not quite, flow through the gas. When an ionizing particle came into contact with the wire, it disturbs the system enough to complete the circuit, and the resulting completion can be detected by an audible click or by a pointer, depending on the type of counter.

Once it was possible to reliably detect, and therefore count, alpha particles, Rutherford devised an experiment to determine the charge on an alpha particle. In ‘The charge and nature of the [alpha]-particle’ (pp. 162-73 in the present issue), Rutherford and Geiger report the results of that experiment, namely that the charge on an alpha-particle is twice the electronic charge.

Hans Geiger (1882-1945) studied physics at the University of Munich and served in the German military before pursuing graduate studies at Erlangen, earning his PhD in 1906 with a thesis on electrical releases through gases. He then moved to England to become a laboratory assistant in Rutherford’s laboratory at the University of Manchester. In 1909 he conducted the famous ‘gold foil experiment’ with Ernest Marsden, and in 1911 he and John Nuttall discovered the ‘Geiger-Nuttall law’ relating the rate of radioactive decay to the energy of the emitted alpha-particles. In 1914, Geiger returned to Germany, initially to take charge of radiation research at the National Institute for Science and Technology. After World War I, during which he served as an artillery officer, Geiger returned to research, finding a position at the University of Kiel where he collaborated with one of his doctoral students, Walther Muller, on improving his original Geiger counter device, making it more efficient, responsive, durable and portable. Unlike the earlier version, which could detect only alpha particles, the new improved Geiger-Muller counter could detect many different kinds of ionizing radiation. He used the new device to confirm the existence of light quanta in 1925, and later to discover cosmic ray showers, which would claim his scientific attention for the remainder of is career. Geiger was a member of the so-called Uranium Club, a clandestine German effort to develop and produce atomic weapons after the discovery of atomic fission in 1939. The program splintered in 1942, with its scientists moving to other areas of research deemed more urgent, after it was determined (incorrectly) that nuclear fission would not play a major role in ending the war.

In: Proceedings of the Royal Society, Series A, Vol. 81, No. 546, August 27, 1908, pp. 141-161. The entire issue offered here in original grey printed wrappers. Large 8vo (256 x 177 mm), pp. 141-220. A very fine and unrestored copy.

Item #3586

Price: $1,400.00

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