[en] A = 110 isobars separated by IGISOL on-line mass separator from fission products has been investigated by using Beta-gamma and gamma-gamma coincidence techniques. A new quasi-particle level at 2261 keV in ¹¹⁰Pd was observed. Systematics of logft-values and excitation energies of the quasi-particle levels in even-even Pd isotopes is remarkably smooth. An excited 0⁺ state at 1137 keV in ¹¹⁰Ru was identified and the 2₃⁺ state at 1396 keV was confirmed. Systematics of these low-spin excited states in even-even Ru isotopes gives a hint for intruder character of these states. (author)

[en] For some proton-very-rich nuclei the emission of one proton is forbidden and the only way that complies with the energy conservation law is the emission of 2 protons simultaneously, which is called the double-proton decay. This way of decay was predicted from theoretical studies about the existence of nucleon pairing inside the nucleus. The production of new isotopes through the collisions of heavy ions has led to the experimental confirmation of first, the one-proton decay (in the eighties at Darmstadt through Lu¹⁵¹ → Yb¹⁵⁰ + p) and then, the double-proton decay (in GANIL and in GSI, in 2002) through Fe⁴⁵ → Cr⁴³ + p + p. In the GANIL experiment the Fe⁴⁵ nuclei were produced in the collisions of high energy Ni⁵⁸ nuclei with a target of natural nickel (200 g/cm²). In some collisions (called fragmentation reactions) the target nuclei strip the nucleus incident of some nucleons producing a lighter nucleus, here Fe⁴⁵. In order to produce one nucleus of Fe⁴⁵, it has required in the GANIL conditions, the fragmentation of 10¹⁵ to 10¹⁶ incident nuclei of Ni⁵⁸. In GSI similar results have been obtained with the double-proton decay of Zn⁵⁴. (A.C.)

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[en] In the context of a parameter study conducted by several laboratories for future European radioactive beam facilities based on fast-neutron induced fission, in particular for the SPIRAL-II project at GANIL, we have measured the yields of neutron-rich isotopes in the mass range of 88 to 144. These nuclei were obtained as fission products of natural uranium bombarded by neutrons of 20 MeV average energy emitted by a thick carbon target irradiated by 50 MeV deuterons. Yields have been measured using on-line mass separation with the ion-guide method. Compared with proton-induced fission at 25 MeV the magnitude of cross-sections, except for the symmetric region, is similar. Z-distributions of isobars have the same width, 0.7 charge units, but their maxima are shifted by about 0.8 charge units, favouring production of the neutron-richer isobars. Our data allow calculations of absolute cross-sections for fission of natural uranium induced by neutrons of about 20 MeV. (orig.)

[en] Our studies have been devoted to the nuclear structure of nuclei far off the valley of β-stability. For the neutron deficient side, we have installed our ion guide on-line with the K = 130 cyclotron at Jyaeskylae and carried out successful experiments on light rare-earth elements. At GANIL we have discovered a new island of 'μs isomers' around Z = 28 and N = 40 among the products of quasi-fragmentation of a 60.3 A.MeV ⁸⁶Kr beam by using a novel IL-γ correlation technique. (authors)

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[en] Kr"8"1 (T_1_/_2 = 2.29*10"5 y), that is produced in the atmosphere by cosmic rays and Kr"8"5 (T_1_/_2 = 10.77 y), that is produced in the fission of nuclear fuels, are considered as the right chronometer elements for the dating of underground waters, polar ice, of for tracking civil and military nuclear activities. The use of Kr"8"1 and Kr"8"5 implies the development of extracting lines and detection devices with so high accuracy that only a few thousands of krypton atoms can be detected. The approach developed aims at detecting Kr"8"1 and Kr"8"5 in 1 liter of air and 20 liters of water. 3 steps are necessary. The first step consists in separating and purifying the krypton. The extraction of gases from water is made by helium bubbling. Chemically active gases like N_2, CO_2, CH_4 and O_2 are eliminated by chemical traps while Ar si separated by cryogenics. The second step involves a double focus mass spectrometer designed to perform an important enrichment in Kr"8"1 and Kr"8"5. The last step is the high-accuracy measurement of krypton isotopes performed with the new tool named FAKIR (Facility for Analyzing Krypton Isotopic Ratios) that is based on UV laser ionization and on the mass-discrimination of the ions through their time of flight

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