NEWGAIN White Book - Science Requirements - Work Package Physics

The new injector for SPIRAL2 at GANIL, NEWGAIN is presently in its design phase. The major constraints for its technical concepts are determined by the requirements of its future users, the national French and the international scientific communities. The facility will offer heavy ion beams of unmatched intensity for fundamental and applied research. This document reports on the specific requirements of the scientific communities in terms of beam energy, intensity, time structure and other features which are needed to conduct the envisaged research programs at the experimental installations, which are or will be coupled to the linear accelerator of the SPIRAL2 facility at GANIL. It aims at fostering the information exchange between the scientific community and the technical and engineering team who is designing, planning and constructing NEWGAIN. The document has been elaborated by the members of the Work Package Physics (WPP) of the NEWGAIN project, consisting of the scientific coordinators of the institutions contributing to and participating in NEWGAIN, and representatives of the various scientific collaborations engaged in the exploitation of the SPIRAL2 accelerator facility. The document is organized with active links to sections, subsections, figures, tables and literature references integrated in the text

NEWGAIN White Book - Science Requirements - Work Package Physics

The new injector for SPIRAL2 at GANIL, NEWGAIN is presently in its design phase. The major constraints for its technical concepts are determined by the requirements of its future users, the national French and the international scientific communities. The facility will offer heavy ion beams of unmatched intensity for fundamental and applied research. This document reports on the specific requirements of the scientific communities in terms of beam energy, intensity, time structure and other features which are needed to conduct the envisaged research programs at the experimental installations, which are or will be coupled to the linear accelerator of the SPIRAL2 facility at GANIL. It aims at fostering the information exchange between the scientific community and the technical and engineering team who is designing, planning and constructing NEWGAIN. The document has been elaborated by the members of the Work Package Physics (WPP) of the NEWGAIN project, consisting of the scientific coordinators of the institutions contributing to and participating in NEWGAIN, and representatives of the various scientific collaborations engaged in the exploitation of the SPIRAL2 accelerator facility. The document is organized with active links to sections, subsections, figures, tables and literature references integrated in the text

Decay properties of neutron-deficient isotopes 256,257Db^{256, 257}Db, 255Rf^{255}Rf, 252,253Lr^{252, 253}Lr

Isotopes of dubnium (element 105) with mass numbers $A = 256$, 257, and 258 were produced by the reaction $^{209}$Bi($^{50}$Ti,xn)$^{259-{x}}$Db ($x=1,2,3$) at projectile energies of (4.59-5.08) AMeV. Excitation functions were measured for the 1n, 2n and 3n evaporation channels. The same position of the excitation function was observed for the 1n channel as for the previously measured 1n channel of the reaction $^{208}$Pb($^{50}$Ti,1n)$^{257}$Rf. The measured $\alpha$-decay data of $^{257}$Db and its daughter products resulted in the identification of $\alpha$-decaying isomeric states in $^{257}$Db and $^{253}$Lr. Two new isotopes, $^{256}$Db and $^{252}$Lr, were produced at the highest bombarding energies of 4.97 AMeV and 5.08 AMeV. They were identified by delayed $\alpha$-$\alpha$ coincidences. The measured half-lives are $(1.6^{+0.5}_{-0.3})$ s for $^{256}$Db and $(0.36^{+0.11}_{-0.07})$ s for $^{252}$Lr. Besides $\alpha$-decay, a spontaneous fission activity of $T_{1/2}=(2.3^{+1.1}_{-0.6})$ s was observed and attributed to an electron-capture branch of $^{256}$Db, which feeds the fissioning nucleus $^{256}$Rf. A branching ratio of $0.36 \pm 0.12$ was obtained. The isotope $^{255}$Rf was produced by the reaction $^{207}$Pb($^{50}$Ti,2n)$^{255}$Rf. Improved decay data have been obtained by means of $\alpha$- and $\alpha$-$\gamma$ spectroscopy

Strong influence of the entrance channel on the formation of compound nuclei Th216,222* and their evaporation residues

The dynamical effects of the entrance channel on the formation of the evaporation residues are studied by analyzing the Ar40+Hf176, Kr86+Xe130,136, Sn124+Zr92, and Ca48+Yb174 reactions leading to the Th216* and Th222* compound nuclei. We find that the difference between the evaporation residue cross sections for the reactions leading to the same compound nucleus is caused by the different angular momentum distributions of the partial fusion cross sections σ(Ec.m.). The strong dependence of the fusion angular momentum distribution on the mass (charge) asymmetry and shell structure of reactants is demonstrated. The effect of the A/Z ratio for the Kr86+Xe130,136 reactions is discussed. The dynamical conditions of capture affect the competition between complete fusion and quasifission and, consequently, the shape of the angular momentum distribution of the compound nucleus. By this way the peculiarities of the entrance channel also affect the fission-evaporation competition of the excited intermediate nuclei along the deexcitation cascade of the compound nucleus and, consequently, the evaporation residue formation. © 2005 The American Physical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

S3^3 targets monitoring with an electron gun

International audienceThe monitoring of targets under irradiation was investigated using a 20 keV electron beam. An integrated and automated electron beam deflection was developed allowing a monitoring over the whole surface of target materials. Thus, local defects could be identified on-line during an experiment performed at GANIL involving different materials irradiated with a focused krypton beam at 10.5 MeV/u. Performances of this target monitoring system are presented in this paper

COMPASS-A COMPAct decay spectroscopy set-up

© 2018 Elsevier B.V. A compact silicon detector array with high spatial granularity and fast, fully digital data recording has been developed and commissioned for the investigation of heavy and superheavy nuclear species. The detector array can be combined in close geometry with large volume germanium detectors. It offers comprehensive particle and photon coincidence and correlation spectroscopy by highly efficient evaporation residue, α γ conversion electron and X-ray detection supported by the high granularity of the implantation chip. Access to fast decay events in the sub-microsecond region is made possible by the fast timing properties of the digital signal processing. A novel Si-chip support design allows direct cooling of the Si-chips and short signal transport. The compact and modular mechanical design equipped with a standard flange facilitates its transport and connection to different separators at different ion beam facilities. After initial tests, first α-γ coincidence spectroscopy experiments have been performed at the LISE separator of GANIL in Caen, France, in FULIS (velocity filter) mode and at the velocity filter SHIP of GSI in Darmstadt, Germany.status: publishe