currently in Rome, Italy b
This paper was written while Hans Bethe was visiting the Institute of Physics of the Royal University of Rome, under invitation of Enrico Fermi.
Received in final form: 18 September 2014
Published online: 25 November 2014
From the theory of Møller [Møller, Chr. 1931. Über den Stoß zweier Teilchen unter Berücksichtigung der Retardation der Kräfte. Zeitschrift f. Phys. 70: 786–795] the energy loss of electrons with relativistic speeds passing through matter is derived. The energy loss per centimeter of distance reaches a minimum at about 96% of the speed of light and increases again at higher speeds; for electrons of several billion Volt it is about 4 million Volt per centimeter of water. A table of the theoretical energy loss for electrons and protons of various speeds is given.
The German original was published as Bethe, H. 1932. Bremsformel für Elektronen relativistischer Geschwindigkeit. Zeitschrift f. Phys. 76: 293–299.
The current translation is by Klaus Bartschat, Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA; firstname.lastname@example.org. An attempt has been made to preserve Bethe’s writing style as much as possible, including his use of “Volt” instead of “electron volt”. Even though the term “stopping power” is quite common in present scientific English, we generally use “braking [capability]” rather than “stopping [power]”, in order to emphasize the act [and ability] of slowing down the particle rather than the ultimate result of bringing it to a complete halt. Also, a few typographical errors were kept in the English translation to ensure the translation replicates the original paper. Please, see Section 3 of the annotation to Bethe’s article [Fontes, C.J., Bostock, C.J. and Bartschat, K. 2014. Eur. Phys. J. H, 39: 517-536] for a list. The references were converted to EPJH style, and the footnotes are numbered consecutively.
© EDP Sciences, Springer-Verlag 2014