Using resonant two-step laser excitation of trapped 232Th+ ions, we observe 166 previously unknown energy levels of even parity within the energy range from 7.8 to 9.8 eV and angular momenta from J=1/2 to 7/2. We also classify the high-lying levels observed in our earlier experiments by the total angular momentum and perform ab-initio calculations to compare their results with the observed level density. The observed levels can be relevant for the excitation or decay of the 229mTh isomeric nuclear state which lies in this energy range. The high density of electronic levels promises a strongly enhanced electronic bridge excitation of the isomer in 229Th+.
https://www.nuclock.eu/wp-content/uploads/2015/07/nuclock-color-300x77.png 0 0 Thorsten Schumm https://www.nuclock.eu/wp-content/uploads/2015/07/nuclock-color-300x77.png Thorsten Schumm2019-04-24 10:45:402019-04-24 10:45:40Electronic level structure of Th+ in the range of the 229mTh isomer energy