AP-Seminare

# Towards Precision Spectroscopy of HCIs and Nuclei Using Extreme Ultraviolet Frequency Combs

## by Christoph Heyl (DESY/Jena)

Wednesday, June 19, 2019 from to (Europe/Berlin)
at GSI ( KBW Lecture Hall - Side Room )
 Description The advent of the optical frequency combs about two decades ago has provided a direct link between optical frequencies and the radio-frequency domain where our standard unit of time, one second, is defined. Frequency combs are nowadays routinely employed for precision spectroscopy in the visible and near-infrared spectral region and have left a major impact in modern AMO physics. In contrast, the extreme ultraviolet (XUV) presents a barely explored area for precision spectroscopy studies with promising targets such as ground state transitions in helium, highly charged ions (HCIs) and possibly nuclei. The extension of this comb-based frequency link all the way into the extreme ultraviolet is nowadays possible and might enable the next breakthroughs in AMO or even nuclear physics. In fact, very recent works seem to pave the way for the first direct laser excitation of a nuclear transition in 229Thorium – a task that could be accomplished e.g. by a VUV frequency comb source operating at a wavelength around 150 nm. In this talk, I will give an introduction into our XUV frequency comb activities at DESY and Helmholtz-Institute Jena, presenting our effort in developing a state-of-the-art XUV comb system, a tool that can bridge the gap between two important fields within modern AMO physics: precision spectroscopy and attosecond science.