Frequency-comb based collinear laser spectroscopy of Be for nuclear structure investigations and many-body QED tests

Abstract

Absolute transition frequencies of the $2s{}^2{\mathrm{S}}_{1/2}$ $\to$ $2p{}^2{\mathrm{P}}_{1/2,3/2}$ transitions in Be${}^{+}$ were measured with a frequency comb in stable and short-lived isotopes at ISOLDE (CERN) using collinear laser spectroscopy. Quasi-simultaneous measurements in copropagating and counterpropagating geometry were performed to become independent from acceleration voltage determinations for Doppler-shift corrections of the fast ion beam. Isotope shifts and fine structure splittings were obtained from the absolute transition frequencies with accuracies better than 1\,MHz and led to a precise determination of the nuclear charge radii of ${}^{7,10-12}$Be relative to the stable isotope ${}^9$Be. Moreover, an accurate determination of the $2p$ fine structure splitting allowed a test of high-precision bound-state QED calculations in the three-electron system. Here, we describe the laser spectroscopic method in detail, including several tests that were carried out to determine or estimate systematic uncertainties. Final values from two experimental runs at ISOLDE are presented and the results are discussed.

28 pages, 12 figures

References in corpus (7)

• Nuclear Charge Radii of Be-7,9,10 and the one-neutron halo nucleus Be-11
• Relativistic, QED, and finite nuclear mass corrections for low-lying states of Li and Be${}^{+}$
• Precision high voltage divider for the KATRIN experiment
• Fine and hyperfine splitting of the 2P state in Li and Be${}^{+}$
• Quantum electrodynamics corrections to the $2P$ fine splitting in Li
• Calibration of the ISOLDE acceleration voltage using a high-precision voltage divider and applying collinear fast beam laser spectroscopy
• Precision Test of Many-Body QED in the Be${}^{+}$ $2p$ Fine Structure Doublet Using Short-Lived Isotopes

Cited by in corpus (1)

• Detecting weak beryllium lines with CUBES