TY  - GEN
ID  - heidok28293
TI  - High-Precision Laser Spectroscopy of the Fine Structure
in 40Ar13+ at ALPHATRAP
Y1  - 2020///
A1  - Egl, Alexander
CY  - Heidelberg
AV  - public
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/28293/
N2  - The cryogenic double Penning-trap experiment ALPHATRAP aims to test bound-state quantum electrodynamics (BS-QED) under extreme conditions by measuring the magnetic moment (g-factor) of electrons bound to the nucleus of heavy highly charged ions (HCIs). The bound electron g-factor is measured employing the double-trap technique which uses the continuous Stern-Gerlach e?ect (CSGE) for a nondestructive detection of the spin state of the ion. The result of this thesis is twofold.
In order to improve the achievable precision of future measurements the implementation of sympathetic laser cooling is envisaged. For this purpose a laser system was integrated into the existing setup and laser cooling of 9Be+ was demonstrated for the ?rst time at ALPHATRAP. For the axial temperature of a single beryllium ion an upper limit of 69(30) mK can be given. This demonstration paves the way for further developments
towards sympathetic laser cooling of HCIs.
Furthermore, the optical access to the Penning trap was used for high-precision laser spectroscopy of the magnetic dipole ?ne structure transition in the ground state of boronlike argon 40Ar13+ with an unsurpassed relative uncertainty of the absolute frequency of 9.4×10e?9. To this end, a novel spectroscopy scheme was demonstrated for the ?rst time, which uses the CSGE and does not require a detection of ?uorescence. This
proof-of-principle method can be extended to other systems, opening up new possibilities to test BS-QED in the strongest electromagnetic ?elds by investigating the optical hyper?ne structure in heavy HCI by means of laser spectroscopy.
ER  -