%0 Journal Article
%T Single electron detection and spectroscopy via relativistic cyclotron radiation
%A D. M. Asner
%A R. F. Bradley
%A L. de Viveiros
%A P. J. Doe
%A J. L. Fernandes
%A M. Fertl
%A E. C. Finn
%A J. A. Formaggio
%A D. Furse
%A A. M. Jones
%A J. N. Kofron
%A B. H. LaRoque
%A M. Leber
%A E. L. McBride
%A M. L. Miller
%A P. Mohanmurthy
%A B. Monreal
%A N. S. Oblath
%A R. G. H. Robertson
%A L. J Rosenberg
%A G. Rybka
%A D. Rysewyk
%A M. G. Sternberg
%A J. R. Tedeschi
%A T. Thummler
%A B. A. VanDevender
%A N. L. Woods
%J Physics
%D 2014
%I arXiv
%R 10.1103/PhysRevLett.114.162501
%X It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. We observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta elec- tron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments.
%U http://arxiv.org/abs/1408.5362v2