K. P. Marinova

Nuclear charge radii changes of uranium and hafnium isotopes determined by laser spectroscopy

The present work reports measurements of isotope shifts and hyperfine structure in the optical spectra of two high-Z elements: Hf and U. The experiments are based on the observation of the resonance fluorescence in a well collimated atomic beam, excited by a tunable dye laser. The chains of the stable Hf isotopes and of233–236, 238U have been investigated and changes in ms nuclear charge radii have been deduced. The results have been discussed from the point of view of nuclear structure in the investigated regions.

J dependences of the isotope shifts in Ti I 3d24s2 a 3P and 3d34p y 3Do terms

Atomic beam laser spectroscopy was used to measure the isotope shifts (IS) and hyperfine structures of all stable titanium isotopes in eight Ti I spectral lines. Six of the lines investigated cover all allowed transitions between the lower 3d24s2 a 3P and the upper 3d34p y 3Do terms; two of them are between the 3d24s2 a 3P1,2 and 3d24s4p z 3P2o levels. J-dependences of the IS in the a 3P and y 3Do terms were established. The contributions of the field and mass shifts to the J-dependence were separated using model-independent data on muonic atom IS and electronic scattering experiments. Evidence for mass shift domination of the J-dependence was provided.

Accurate isotope shift measurements on short-lived neon isotopes

We report on fast beam collinear laser spectroscopy measurements that demonstrate the feasibility of accurate isotope shift measurements for short lived Ne isotopes including the proton halo candidate 17Ne. Ultra high sensitivity is achieved by the application of an efficient resonance detection scheme based on collisional ionization and ion counting via the β decay. A direct measurement of the kinetic energy of the atomic Ne beam provides the required high accuracy.

Isotope shifts and hyperfine splitting in HfI changes in nuclear charge radii of stable isotopes and182Hf

Isotope shifts and hyperfine structures in three optical transitions of HfI are investigated. Magnetic dipole coupling constant A and electric quadrupole coupling constant B of four atomic levels for both stable odd-even isotopes177Hf and179Hf are determined. Nuclear charge radii changesδ〈r2〉 of the stable Hf isotopes and182Hf (T1/2=9×106 y) are extracted using the standard semiempirical procedure. Strong deviation from muonic atom data onδ〈r2〉 is observed. The course of theδ〈r2〉 dependence on mass number indicates changes in nuclear deformation at A=174 and influence of higher order deformations on nuclear shape in this region.

Optical isotope shifts and changes in nuclear charge radii of stable Ti isotopes

Isotope shifts and hyperfine structures in three optical transitions of TiI have been investigated by using laser induced resonance fluorescence in a collimated atomic beam. From the isotope shifts data, changes of the mean square charge radii of the stable titanium isotopes have been determined for the first time. Using a combined analysis with muonic atom data on root mean square nuclear charge radii, improved model independent 〈r2〉1/2 values for the odd-even Ti isotopes have been obtained.

Efficient β-BaB2O4 frequency-doubler for ultraviolet laser spectroscopy of radionuclides

Efficient frequency-doubling systems with a specific geometry configuration are used in order to obtain ultraviolet (UV) cw coherent radiation for laser spectroscopy of exotic radionuclides in the 30 ⩽ &Zgr; ⩾ 58 region. The compensation of the walk-off angle and the use of external cavity for second harmonic generation give most noticeable doubler efficiency increase. Three frequency-conversion systems are proposed for laser spectroscopy of nuclei. Second harmonic efficiency of 18% is obtained. Perspectives of using the injection seeded nonlinear converters in laser spectroscopy are also discussed.

Nuclear spin and moments of 73Kr and odd—even staggering in the radii of light krypton isotopes

Nuclear spectroscopy measurements in the region of neutron-deficient krypton isotopes have indicated that pronounced shape changes and instabilities occur when the nuclei approach the N = Z line. This is confirmed by isotope shift measurements on krypton [1] yielding an increasing inverted odd—even staggering of the radii [2] from 82Kr (N = 46) to 74Kr (N = 38). We have now completed the published data by measuring the hyperfine structure and isotope shift of 73Kr. This is also interesting in context with a recent β-decay study [3]. The feeding of excited states in 73Br gave strong arguments for the ground-state spin and parity of 73Kr to be 3/2−, in contrast to the adopted assignment of 5/2−.