Energy levels of Th+ between 7.3 and 8.3 eV
Abstract
Using resonant two-step laser excitation of trapped 232Th+ ions, we observe 43 previously unknown energy levels within the energy range from 7.3 to 8.3 eV. The high density of states promises a strongly enhanced electronic bridge excitation of the 229mTh nuclear state that is expected in this energy range. From the observation of resonantly enhanced three-photon ionization of Th+, the second ionization potential of thorium can be inferred to lie within the range between 11.9 and 12.3 eV. Pulsed laser radiation in a wide wavelength range from 237 to 289 nm is found to provide efficient photodissociation of molecular ions that are formed in reactions of Th+ with impurities in the buffer gas, leading to a significantly increased storage time for Th+ in the ion trap.
Keywords
Cite
@article{arxiv.1305.0765,
title = {Energy levels of Th+ between 7.3 and 8.3 eV},
author = {O. A. Herrera-Sancho and N. Nemitz and M. V. Okhapkin and E. Peik},
journal= {arXiv preprint arXiv:1305.0765},
year = {2013}
}
Comments
7 pages, 6 figures