%0 Generic
%A Bilous, Pavlo
%D 2019
%F heidok:25789
%R 10.11588/heidok.00025789
%T Towards a nuclear clock with the 229Th isomeric transition
%U https://archiv.ub.uni-heidelberg.de/volltextserver/25789/
%X The 229Th nucleus with its 7.8 eV isomeric state is a unique candidate for the first nuclear  optical clock at an exceptional accuracy of 10−19. Due to the low isomeric transition  energy, the coupling to the atomic shell in the processes of internal conversion (IC) or  electron bridge (EB) is very strong. In this work we investigate theoretically the IC and  EB mechanisms and design novel laser-assisted schemes aimed at (i) a more accurate  determination of the isomer energy Em and (ii) efficient excitation of the isomer. On  the one hand, we show how IC occurring from excited electronic states of Th ions can  be used to determine the isomeric transition energy. We also propose a new approach  to measure the isomer energy with laser spectroscopy accuracy via laser-induced EB in  229Th3+ ions. On the other hand, we put forward possible isomer excitation schemes  based on the EB process in highly charged Th ions or on laser-assisted nuclear excitation  by electron capture of the 29.19 keV nuclear state lying directly above the isomer. Our  results show that EB in highly charged ions which allow optical driving with high-power  lasers should lead to efficient excitation. Such a setup using ion traps might become  relevant for the future development of the nuclear clock.