R.F. Garcia Ruiz

Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy.

New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t_{1/2}=22.0(5) ms] ^{219}Fr Q_{s}=-1.21(2) eb, which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in two-step resonance ionization. Exotic nuclei produced at rates of a few hundred ions/s can now be studied with high resolution, allowing detailed studies of the anchor points for nuclear theories.

Spins and Magnetic Moments of 49K and 51K: Establishing the 1/2+ and 3/2+ Level Ordering Beyond N=28

The ground-state spins and magnetic moments of (49,51)K have been measured using bunched-beam high-resolution collinear laser spectroscopy at ISOLDE CERN. For 49K a ground-state spin I = 1/2 was firmly established. The observed hyperfine structure of 51K requires a spin I > 1/2 and strongly suggests I = 3/2. From its magnetic moment μ(51K) = +0.5129(22)μ(N) a spin-parity I(π) = 3/2+ with a dominant π1d(3/2)(-1) hole configuration was deduced. This establishes for the first time the reinversion of the single-particle levels and illustrates the prominent role of the residual monopole interaction for single-particle levels and shell evolution.

Ground-state electromagnetic moments of calcium isotopes

High-resolution bunched-beam collinear laser spectroscopy was used to measure the optical hyperfine spectra of the

Nuclear charge radii of potassium isotopes beyond N = 28

^{43-51}

Shell structure of potassium isotopes deduced from their magnetic moments

Ca isotopes. The ground state magnetic moments of

Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry

^{49,51}

arXiv : Dipole and quadrupole moments of

Ca and quadrupole moments of

^{73-78}

^{47,49,51}

Cu as a test of the robustness of the

Ca were measured for the first time, and the

Z=28

^{51}