Properties of Fr-like Th3+from rf spectroscopy of high-LTh2+Ryd

Abstract

Relative positions of twenty n = 28 Rydberg levels of Th 2+ with L = 9, 10, 11, and 12 were determined with sub-MHz precision using the rf-RESIS (resonant excitation Stark ionization spectroscopy) technique. The pattern of binding energies was analyzed with the effective potential model, modified to account for significant nonadiabatic effects. The analysis yielded measurements of several properties of the Fr-like Th 3+ core ion, including the quadrupole moment, Q = 0.5931( 14) a.u.; hexadecapole moment, = − 0.69(28) a.u.; g factor, g J = 1.24(48); scalar and tensor dipole polarizabilities, α D ,0 = 15.224(33) a.u. and α D ,2 = − 5.30(11) a.u.; scalar quadrupole polarizability, α Q,0 = 60(15) a.u.; and the reduced dipole and octupole matrix elements connecting the ground 5f 2 F 5/2 level with the low-lying 6d1.1) a.u. The measured properties are compared with theoretical predictions.

Radiative transitions between Rydberg states of polar diatomic molecule. Part I: Linearly polarized light

“…IBO approximation takes place for high RSs when the precession of the Rydberg electron orbit is slower than the rotation of the core [14]:…”

“…High-l non-penetrating RSs are of particular interest because the interpretation of their spectra allows to extract properties of the core (atomic or molecular) with high precision [11,12]. Recent identification of many new high-l series [13][14][15][16][17] in atomic spectra allows to expect appearing precise spectroscopic data on non-penetrating RSs in molecules.…”

Atomic properties of actinide ions with particle-hole configurations

“…there is no experimental data for any of the energy levels. A very successful program was established to measure the dipole and quadrupole polarizabilities of Th ions with resonant excitation Stark ionization spectroscopy (RESIS) method [22][23][24][25][26]. In the RESIS method, a non-penetrating Rydberg electron is attached to the ion of interest to measure the binding energies of the resulting high-L Rydberg states [22].…”

Relativistic all-order calculations of Th,Th+, andTh2+atomic properties

“…The combination of the experimental measurements of hyperfine constants of Th 3+ with theoretical calculations has enabled accurate determination of magnetic dipole and electric quadrupole moments [15]. Analysis of resonant excitation Stark ionization spectroscopy spectra has led to the determination of Th 3+ ground-state electric quadrupole moment, adiabatic scalar and tensor dipole polarizabilities, and the dipole matrix elements connecting the ground level to low-lying excited levels of Th 3+ [16]. Due to the more complicated atomic structure of Th 2+ , Th + and Th, which have respectively two, three and four valence electrons, their atomic properties are less precisely known than that of Th 3+ .…”