[en] Accelerators of low and intermediate energy, particularly electrostatic generators and cyclotrons, are suitable tools for basic and applied research that developing countries can acquire. The current status and the development in progress concerning such equipment as well as the field of research are outlined

[en] Several cases of spontaneous emission of fragments from heavy nuclides have been experimentally observed up to now. So, spontaneous decays intermediate between α-decay and fission, previously predicted, are definitively established. Three experimental techniques have been involved so far giving a striking agreement in branching ratio measurements. The first technique of a ΔExE solid state detector telescope placed in a direct view of the source as in the discovery of the phenomenon seems to have no role left to play. The second technique based on a magnetic selection of the fragments from the very high flux of α-particles is much more powerful in fragment/α branching ratio measurements and present a specific interest in its capability of measuring with precision various characteristics of the fragments, e.g. the energy, Z, A... It is however, the third technique using track solid detectors which seems to yield the smallest fragment/α branching ratios, and consequently to have in the future the most important role to play

[en] The aim of this report is to review the experiment of Rose and Jones (discovery in 1984 of radioactive decay of ²²³Ra by ¹⁴C nuclei emission) with the subsequent one of Alexandrov (et al) performed with the same technique. The experiments performed by the group at Orsay on ¹⁴C radioactivity of radium isotopes with the magnetic spectrometer Soleno are also reviewed. This review comprises the presentation and comments of the original results and arguments taken in their historical context

[en] The ⁴⁸Ca(³He,d)⁴⁹Sc reaction has been studied at 25 MeV incident energy. Angular distributions have been measured from 5⁰ to 40⁰ using a split pole spectrometer, for about 160 levels located up to 18 MeV excitation energy. A local zero range DWBA analysis has been carried out, using Gamow functions as form factors in the case of unbound states; l assignments and spectroscopic factors are obtained for a large number of levels, most of them previously unknown. The summed experimental spectroscopic strengths for the T, l=1 and l=3 levels are in good agreement with the shell-model sum rule limits for 1f-2p proton states, and their energy centroids have been determined. The 1g(9/2) strength in ⁴⁹Sc is strongly fragmented: about 27% of the T strength is carried by twenty three levels located between 6.5 and 13.5 MeV. Spectroscopic factors for analog states are compared with those from previous (p,p), (³He,dp) and (d,p) experiments

[en] Decay of Ra isotopes (A=22,224,226) with emission of ¹⁴C clusters is studied. Spectra of the emitted ¹⁴C clusters at population of different levels of Pb daughter isotopes are measured

[en] The (tau,α) reaction on ⁴⁸Ca, ⁵⁰Ti, ⁵²Cr and ⁵⁴Fe target nuclei has been studied at 25 MeV incident energy. Angular distributions have been measured from 5⁰ to 40⁰ with a split-pole spectrometer in a large range of excitation energy. A local zero-range DWBA analysis has been carried out, using an isospin dependent potential for the calculation of the neutron form factor, in order to get a coherent set of spectroscopic factors for both T> and T< levels in different nuclei. Assignments of l-values have been done for a large number of levels, most of them previously unknown, and energy centroids of hole states have been determined. Spectroscopic factors in ³⁹Ca, ⁴⁷Ti, ⁴⁹Cr, ⁵²Cr, ⁵³Cr have also been obtained for strongly excited states. A sum rule analysis has been carried out for the N=27 nuclei: the 1d3/2 and 2s1/2 T< hole strengths are generally fully exhausted by the observed levels, whereas only a fraction of the 1d5/2 strength has been evidenced. The 1f7/2, 1d3/2 and 2s1/2 analog states have been observed in all nuclei; in ⁵³Fe, the 1d3/2 and 2s1/2 analog states appear to be split in several components. In addition, a CRC analysis has been carried out for some levels with angular distributions not accounted for by a direct pick-up process. These levels are tentatively identified with states resulting from the coupling of one f7/2 neutron hole with excited states of the target nucleus. In particular, the 5/2^- and 9/2^- members of the configuration have been identified in each final nucleus. Unambiguous Jsup(π) assignments are made; and the two-step (tau,α) reaction therefore appears as a useful spectroscopic tool, especially for investigating high spin states

[en] A detection system consisting of a thin film scintillator detector and a solid state detector has been set up and used to measure the time of flight and energy of the fusion evaporation residues collected with the magnetic spectrometer SOLENO at the Orsay Tandem. The linear responses and the timing properties of the system were tested using a ²⁵²Cf source and beams of ¹⁶O, ³²S and ⁵⁸Ni. The system was used to study the mass identification and the collection yield obtained with SOLENO

[en] Abstract only

[en] The ⁴²Ca(α,³He)⁴³Ca reaction has been studied at 36 MeV incident energy. Angular distributions have been measured from 4⁰ to 42⁰ using a split-pole spectrometer and position sensitive Si detectors, for about 40 levels located up to 6 MeV excitation energy. A local zero-range DWBA analysis has been carried out; l=3 and 4 - assignments are tentatively proposed for levels located above 4 MeV excitation energy, indicating a strong fragmentation of the 1fsub(5/2) strength between 4 and 6 MeV and the location of the main component of the 1gsub(9/2) strength above 6 MeV. A number of weakly excited levels cannot be reproduced by DWBA analysis. Their angular distributions have been compared with the results of coupled-reaction-channel calculations assuming two-step excitation of weak coupling states with a [⁴²Ca*-fsub(7/2)] structure. A reasonable agreement has been obtained, confirming that the two-step process cannot be neglected in the analysis of (α,³He) reaction

[en] A new type of spectrometer for nuclear charged particles studies has been designed and built near the 13 MV Tandem accelerator of the Institut de Physique Nucleaire at Orsay (France). It makes use of the focusing properties of an axial magnetic field of 3.17 Teslas (at maximum value) produced by a superconducting solenoidal coil. The basic properties of such a device are the followings: true azimuthal symmetry, large angular acceptance (up to 10⁰), reduced geometrical and mechanical aberrations leading to a bandwith of 5% in magnetic rigidity. Associated with system of detection of small size, this spectrometer is now used around zero degree for coincidence experiments and to collect and identify in mass, fusion evaporation residues. In this later case, the system is operating like a recoil mass separator (RMS)