Berlin 2001 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MS: Massenspektrometrie
MS IV: HV IV
MS IV.1: Invited Talk
Friday, April 6, 2001, 15:00–15:30, Audimax
ECAMP7 HOT TOPIC: High-Accuracy Determination of the Atomic Mass of the Electron — •W. Quint1, T. Beier1, H. Häffner2, N. Hermanspahn2, S. Karshenboim3, H.-J. Kluge1, G. Marx1, T. Valenzuela2, J. Verdu1, and G. Werth2 — 1GSI Darmstadt, Germany — 2Universität Mainz, Germany — 3Mendeleev Institute for Metrology, St. Petersburg, Russia
We report on a high-accuracy determination of the electron mass in atomic units (u). Our mass determination is based on the measurement of the Larmor precession frequency of the bound electron in the hydrogen-like carbon ion 12C5+. In our experiment, a single 12C5+ ion is stored in the magnetic field of a Penning trap [1,2]. The Larmor frequency of the bound electron is measured by inducing quantum jumps between the two spin states (spin up and spin down) of the electron. The magnetic field strength is calibrated via the cyclotron frequency of the 12C5+ ion. Our value for the electron mass me = 0.000 548 579 909 2 (5) u is the most accurate measurement of the electron mass so far. Also, we deduce a new value for the electron-proton mass ratio.
[1] N. Hermanspahn et al. Phys. Rev. Lett. 84, 427 (2000).
[2] H. Häffner et al., Phys. Rev. Lett. 85, 5308 (2000).