[en] With the rebuilt ISOLDE 2 facility, the ¹⁸⁰Hg decay products have been investigated on-line. The decay half-lives, the energy and intensity of the main γ lines of ¹⁸⁰Hg and ¹⁸⁰Au have been measured and a tentative decay scheme of ¹⁸⁰Pt was given

[en] A fully operational electron-guide, constituted by the succession of a toroidal magnetic lens and a solenoid, is described and its properties are tested. An absolute efficiency between 1% and 2.2% is obtained in a large energy range, from 150 keV to more than 2 MeV, together with a large β⁺ rejection. It is shown that a substantial efficiency increase can be obtained by superposing an axial magnetic field on the toroidal one

[en] The level structures of the N = 89 ¹⁵⁷Er and N = 87 ¹⁵⁵Er nuclei have been investigated through the decay of ¹⁵⁷Tm (Tsub(1/2) = 3.3 min) and ¹⁵⁵Tm (Tsub(1/2) = 25 s). Mass separated samples were obtained from the ISOCELE 1 on-line separator. Gamma ray spectra, conversion electron spectra and γ-γ bi-dimensional coincidences were examined, and lead to proposed level schemes for these transitional nuclei

[en] Mass separated sources of ²²⁷Pa (separated as PaF₄⁺ ions) were used to study the level structure of ²²³Ac following alpha decay. The levels in ²²³Ac are interpreted as K = 5/2^± parity doublet bands which occur naturally in reflection asymmetric models and the multiphonon octupole model. The anomalous structure of the K = 3/2^- band is explained in terms of Coriolis coupling. The low lying parity doublet bands in ²²³Ac, ²²⁵Ac, and ²²⁷Ac are compared and contrasted

No abstract available

[en] The alpha-decay of /sup 225/Th (T/sub 1/2/ = 8mn) to /sup 221/Ra levels was investigated. Mass-separated /sup 225/Th sources were produced with the ORSAY-ISOCELE facility. The selectivity in Z was obtained using fluorination techniques. Single α and γ spectra and α-γ coincidences were simultaneously recorded

[en] The decay of /sup 122/Ba to the odd-odd /sup 122/Cs levels has been studied with on-line mass-separated samples at the Isocele facility. A complex level scheme including 42 new low-spin excited states has been established using gamma and conversion electron spectroscopy techniques. From a series of new measurements, the T/sub 1/2/ = 0.36s /sup 122/Cs isomeric state is proposed at 127 keV with 5^- spin and parity assignments

[en] The decay of ¹²⁴Ba to the levels of odd-odd ¹²⁴Cs has been studied with on-line mass-separated sources delivered at the ISOCELE facility. The energy level scheme has been established from γ-ray singles, γ-γ-t coincidence and e-γ-t coincidence spectra. Spin and parity of several low-lying levels have been assigned on the basis of internal conversion coefficient measurements and β-branchings. A completely new level pattern including approximately 50 levels and ¹⁸⁰ γ-rays is proposed for ¹²⁴Cs. Several features of this level scheme are discussed and compared to those of neighbouring isotopes

[en] A new isotope ¹⁵²Tm(Tsub(1/2) = 5.2 +- 0.6s) and a new isomeric state in ¹⁵⁰Ho(Tsub(1/2) = 88 +- 15s) were observed with the on-line isotope separator ISOCELE II at Orsay. The decay of ¹⁵²Tm is similar to the high spin state (9⁺) in ¹⁵⁰Ho. The new ¹⁵⁰Ho isomer, probably with a low spin (2 or 3), decays mainly to the 2⁺ level in ¹⁵⁰Dy. (orig.)

[en] The reassignment of spins in the low lying level structure of ²¹⁹Ra obtained from the alpha decay of ²²³Th, and minor changes in the spins and the position of the first observed state in the spectroscopy from the nuclear reaction studies ²⁰⁸Pb(¹⁴C,3n)²¹⁹Ra make it possible to correlate these two level structures which were previously unconnected. The resulting level structure shows very tentative K=1/2^± and 5/2^± parity doublet bands and their evolution from anomalous rotational structures into vibrational-like bands with alternating spins and opposite parities, reminiscent of weak coupling to an octupole correlated core. The comparison and contrast of the isobars ²¹⁹Ra and ²¹⁹Fr is also presented. (author) 4 figs., 7 refs