[en] Doppler-free spectra of the 578.2 nm transition of Cul atoms in a hollow cathode discharge have been recorded using Polarization Intermodulated Excitation (POLINEX). The POLINEX spectra, which are free of Doppler-broadened background despite velocity changing elastic collisions, are discussed and related to spectra recorded unter the same experimental conditions with the older intermodulated fluorescence method. (orig.)

No abstract available

No abstract available

[en] The isotope shift in the lambda = 2537 A line of the even isotopes ²⁰⁶Hg, ¹⁹⁰Hg, ¹⁸⁸Hg, ¹⁸⁶Hg, ¹⁸⁴Hg as well as of the I = 13/2 isomers of ¹⁹¹Hg, ¹⁸⁹Hg, ¹⁸⁷Hg, ¹⁸⁵Hg has been measured by use of a tunable dye laser at the on-line masseparator ISOLDE at CERN. The resulting delta< r²> values follow the line, extrapolated from the chain ²⁰⁵Hg-¹⁸⁷Hg which is known to have spherical nuclear shape at the heavy end changing smoothly to slight oblate deformation for the lighter isotopes. Previous measurements of the I = 1/2 groundstates of ¹⁸¹Hg. ¹⁸³Hg and ¹⁸⁵Hg revealed a sharp shape transition to strong deformation. Combined with the new results the following effects can be proved for the first time from the model-independent quantity delta< r²>: 1) the existence of odd even-shape staggering, 2) the coexistence of very different shapes in one and the same nucleus as manifested by the huge isomer shift in ¹⁸⁵Hg, 3) the absence of mixing of the different shapes. (author)

[en] The hyperfine structure of the 2³S-5³P transition in ³He at 294.5 nm was studied by Doppler-free intermodulated fluorescence spectroscopy with the frequency-doubled output of a cw dye laser. The experimental results for the 5³P state are in good agreement with semiempirical calculations. The Fermi contact term for the 5³P state was determined to be -4327.5 +- 5.0 MHz

No abstract available

No abstract available

[en] The spins of several nuclear ground and isomeric states have been measured for a number of mercury isotopes. The fluorescent light from the 6s6p³P₁ state is observed at 2537 Angstroem after excitation with the frequency doubled output of a pulsed dye laser. Four different laser induced fluorescence techniques were tested for their applicability: double resonance, Hanle effect, time delayed integral Hanle beats, and time resolved quantum beats. The sensitivity and selectivity of these models are compared with emphasis on the determination of spins of nuclei far from beta-stability, where short half lives and low production yields restrict the number of available atoms. The experiments were carried out on-line with the ISOLDE isotope separator at CERN at densities as low as 10⁶ atoms/cm³. Results for the very neutron deficient high spin mercury isomers with half lives of several seconds, but also for the ground states of the abundant low spin stable mercury isotopes, are given as examples. The test measurements determined the nuclear spins of the odd sup(185m-191m)Hg isomers to be I = 13/2. (orig.)

[en] An optical pumping apparatus has been attached to the reconstructed ISOLDE on-line mass separator at CERN in order to obtain nuclear data of isotopes far from β stability. As first results the spins of ⁷⁶Rb(Tsub(1/2) = 36.8s) and ¹¹⁹Cs(Tsun(1/2) = 37.7s) have been determined by β radiation detected optical pumping (β-RADOP) to be I = 1 and I = 9/2 respectively. (orig.)

[en] The nuclear spins of the very neutron-deficient /sup 191m/-185mHg isomers were measured on-line at the mass separator ISOLDE at CERN using pulsed-laser excitation and observation of the time-resolved quantum beats from selected hyperfine-structure states. The spins of these isomers are with I=13/2 equal to those of the long-lived isomers /sup 199m/-193mHg already known. The persistence of this spin value for eight isomers is explained by the model of rotation-aligned coupling