title: Wigner crystals of 229Th for optical excitation of the nuclear isomer.
abstract: We have produced laser-cooled Wigner crystals of 229Th3+ in a linear Paul trap. The magnetic dipole (A) and electric quadrupole (B) hyperfine constants for four low-lying electronic levels and the relative isotope shifts with respect to 232Th3+ for three low-lying optical transitions are measured. Using the hyperfine B constants in conjunction with prior atomic structure calculations, a new value of the spectroscopic nuclear electric quadrupole moment Q=3.11(16) eb is deduced. These results are a step towards optical excitation of the low-lying isomer level in the 229Th nucleus.
authors.affiliation: School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Campbell
authors.forename: A G
authors.initials: AG
authors.lastname: Radnaev
authors.forename: A
authors.initials: A
authors.lastname: Kuzmich