Berlin 2001 – scientific programme

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A: Atomphysik

A 19: Electrons, incl. Scattering and Recombination

A 19.8: Talk

Friday, April 6, 2001, 17:30–17:45, H1028

High Precision Measurement of the g_j-factor of the electron bound in hydrogen-like oxygen for testing the Quantum Electrodynamics — •J. Verdú¹, H. Häffner², N. Hermanspahn¹, T. Valenzuela¹, S. Djekic¹, H.-J. Kluge², W. Quint², S. Stahl² und G. Werth¹ — ¹Universität Mainz, 55099 Mainz — ²GSI Darmstadt, Planckstr. 1, 64291 Darmstadt

Text, genau einmal We report on a new measurement of the g_j-factor of the electron bound in hydrogen-like oxygen. Our preliminary result is g_j=2,000 047 017 (5). The experiment was performed on a single ¹⁶O⁷⁺ ion in a double Penning trap. Our result , with a relative accuracy of 2 · 10⁻⁹ , allows the test of performed calculations on bound state QED effects with very high precision. In addition , it opens the possibility of determining fundamental quantities like the electron mass or the fine structure constant α with improved precision compared to currently accepted values. Single particles in a trap represent an almost ideal system for testing physical theories ; for instance, the QED in weak fields could be impressively confirmed through the measurement of the g-factor of the free electron (Δ g/g=10⁻¹¹).The g_j-factor of the bound electron is also affected by additional relativistic and QED-corrections due to the strong electric field of the nucleus. In the present experiment , we prepare and store a single highly charged ion in a Penning trap. The ion is detected and cooled down at 4 K by means of a superconducting tank circuit. For determining the g_j-factor , the Larmor and cyclotron frequencies are measured with very high accuracy. The spinflip transitions are observed non-destructively with the use of a strong magnetic-bottle.