T. Kron

Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion

Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency.

High efficiency resonance ionization of palladium with Ti:sapphire lasers

This work presents the development and testing of highly efficient excitation schemes for resonance ionization of palladium. To achieve the highest ionization efficiencies, a high-power, high repetition rate Ti:sapphire laser system was used and 2-step, 3-step and 4-step schemes were investigated and compared. Starting from different excited steps, the frequencies of the final ionization steps were tuned across the full accessible spectral range of the laser system, revealing several autoionizing Rydberg series, which converge towards the energetically higher lying state of the Pd+ ion ground state configuration. Through proper choice of these excitation steps, we developed a highly efficient, fully resonant 3-step excitation scheme, which lead to overall efficiencies of % and %, measured at two independent mass separator setups. To our knowledge, these are presently the highest efficiency values ever achieved with a resonance ionization laser ion source.

High-resolution laser spectroscopy of long-lived plutonium isotopes

Long-lived isotopes of plutonium were studied using two complementary techniques, high-resolution resonance ionisation spectroscopy (HR-RIS) and collinear laser spectroscopy (CLS). Isotope shifts have been measured on the

Narrow linewidth operation of the RILIS titanium: Sapphire laser at ISOLDE/CERN

5f^67s^2\ ^7F_0 \rightarrow 5f^56d^27s\ (J=1)

First application of the Laser Ion Source and Trap (LIST) for on-line experiments at \{ISOLDE\}

and

Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL

5f^67s^2\ ^7F_1 \rightarrow 5f^67s7p\ (J=2)

In-source laser spectroscopy with the Laser Ion Source and Trap: first direct study of the ground-state properties of 217,219Po

atomic transitions using the HR-RIS method and the hyperfine factors have been extracted for the odd mass nuclei

On-line implementation and first operation of the Laser Ion Source and Trap at ISOLDE/CERN

^{239,241}

APS : In-gas laser ionization and spectroscopy of actinium isotopes near the

Pu. Collinear laser spectroscopy was performed on the

N=126

5f^67s\ ^8F_{1/2} \rightarrow J=1/2\; (27523.61\text{cm}^{-1})