THE RADIOACTIVE ION BEAM FACILITY PROJECT FOR THE LEGNARO LABORATORIES

Abstract In the frame work of the Italian participation to the project of a high intensity proton facility for the energy amplifier and nuclear waste transmutations, the LNL has been proposed a project for the construction of a second generation facility for the production of radioactive ion beams (RIBs) by using the ISOL method. The final goal consists in the production of neutron rich RIBs with masses ranging from 80 to 160 by using primary beams of protons/ deuterons with energy of 100 MeV/u and 100 kW power. This project is proposed to be developed in about 10 years from now and intermediate milestones and experiments are foreseen and under consideration for the next INFN five year plan (1999)(2000)(2001)(2002)(2003). In such period of time is proposed the construction of a deuteron accelerator of 20 MeV energy and 5 mA current, consisting of a RFQ (5 MeV) and a linac (20 MeV), and of a neutron area dedicated to the RIBs production and other applications. Besides the RIBs production, neutron beams for the BNCT applications and neutron physics are also planned. METHODS OF PRODUCTION Two methods can be used to produce RIBs and are the Projectile Fragmentation (PF) and the post-acceleration of isotopes produced by spallation, fragmentation, or fission reactions with high-intensity proton/light-ion beams in thick targets (ISOL method). The ISOL method takes a complementary approach to the production of RIBs. In the ISOL scheme a primary accelerator (or a nuclear reactor) yields a production beam of charged particles (or neutrons), which is sent on a thick, hot target. The radioactive species thereby produced are transported by a transfer tube to an ion source, then mass separated and breeding to higher charge state; the resulting ions are separated by an isotope/isobar separator, post-accelerated and sent into the experimental area. The comparison and choice between the PF and ISOL methods is strongly dependent on the physics to investigate. One of the relevant parameters for a comparison of the ISOL and the PF production methods is the RIBs production luminosity, which is independent of cross-section. The maximum production luminosity expected for an ISOL facility is three or four order of magnitude higher than in the PF figure. This because the luminosity can be achieved through the combination of a thick production target and a very intense primary beam. The proposed researches which are done at near-Coulomb barrier energies and below, involves studies of nuclear structure, low-energy nuclear reactions, astrophysics, and materials sciences applications and are best served by intense, high-quality, low-energy RIBs provided by the ISOL approach. This because the post-accelerator, optimized for high quality beams, provide the easy energy variability, high-energy precision and small emittances as demanded by the experiments. The main drawback to the ISOL method is that the diffusion/desorption from the production target and ionization of radioactive fragments are strongly element-dependent and slower than in the PF method. However, this feature can be also an advantage of the ISOL method because it give Z selectivity and, consequently, enhance beam purity

Indução da brotação de videiras "Cabernet Sauvignon" com uso de Erger® associado ao nitrato de cálcio em Flores da Cunha, RS.

A cadeia produtiva de frutíferas de clima temperado ainda possui gargalos quanto ao tipo e quantidade de produtos utilizados no manejo fitotécnico

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