Hannover 2013 – scientific programme
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A: Fachverband Atomphysik
A 20: Poster: Precision spectroscopy of atoms and ions (with Q)
A 20.11: Poster
Tuesday, March 19, 2013, 16:00–18:30, Empore Lichthof
Spectroscopy of hole transitions in Ir17+ — •Hendrik Bekker1, Alexander Windberger1, Christian Beilmann2, Renee Klawitter3, Piet O. Schmidt4,5, Oscar O. Versolato1, and José R. Crespo López-Urrutia1 — 1Max-Planck-Institut für Kernphysik — 2Karlsruhe institut für Technologie — 3Tri University Meson Facility — 4Physikalisch-Technische Bundesanstalt — 5Leibniz Universität Hannover
Astronomical observations hint at a spatial gradient of the fine structure constant α [1]. Since the Earth moves along this spatial gradient, a temporal variation in α, α, should be observable in the lab. Current estimates for the variation are α / α < 10−19 / year. For a lab measurement of α to be feasible in the foreseeable future, two accurate optical clocks with different sensitivities to α are required. An optical clock with high sensitivity to α can be found by looking at hole transitions in highly charged ions. It has been calculated that due to level crossings the hole transitions in Ir17+ are within optical range, while at the same time this system has one of the highest sensitivities to α [2]. In our electron beam ion trap, Ir17+ ions are prepared and collisionally excited. A grating spectroscope is employed to study the level structure at an aimed accuracy of 1 ppm. Theory cannot predict the electronic structure as accurately as needed. Knowledge of the level structure is therefore an essential prerequisite for future laser spectroscopy experiments in the cryogenic Paul trap CryPTEx.
[1] J.K. Webb et al., Phys. Rev. Lett. 107, 191101 (2011).
[2] J.C. Berengut et al., Phys. Rev. Lett. 106, 210802 (2011).