Experiments on halo nuclei at energies around the Coulomb barrier can provide good quality data o... more Experiments on halo nuclei at energies around the Coulomb barrier can provide good quality data on elastic, inelastic, breakup and nucleon transfer reactions. This information turns out to be very important to understand the structure and dynamics of these exotic nuclei. In this work we present relevant results obtained from recent scattering experiments of 11Be and 6He on heavy targets
The University of Huelva is presently involved in R&D projects for developing RF accelerator cavi... more The University of Huelva is presently involved in R&D projects for developing RF accelerator cavities. Two types of cavities are presently under design, a prototype of room temperature RFQ injector and a quarter-wave resonator for high intensity heavy-ion linear accelerators. The laboratory is equipped with dedicated test-bench for RF measurements, which includes high-power RF generators, network analyzer, amplifiers and power meters. A clean room is also available having a dedicated space for high-precision mechanical metrology and cavity mounting, together with a vertical cryostat for superconducting cavity test.
Elastic scattering of {sup 7}Be+{sup 28}Si was studied at several near barrier energies for probi... more Elastic scattering of {sup 7}Be+{sup 28}Si was studied at several near barrier energies for probing the energy dependence of the optical potential. Our analysis at 17.2 MeV will be presented in this article and discussed, in terms of Continuum Coupled Channel Calculations (CDCC). This research is part of a long term plan concerning the energy dependence of the optical potential for weakly bound projectiles, at near barrier energies and for probing the potential threshold anomaly. The experiment took place at the EXOTIC facility - Laboratori Nationali di Legnaro (LNL), and refers to an angular distribution measurement, using the detector array EXPADES (Exotic Particle Detection System). Results at 9 MeV (Rutherford region) were also analyzed and were used for estimating the solid angle. Our analysis for other energies is under process.
The low-energy part of the LINCE facility [1] can be based on a 72.75 MHz normal-conducting RFQ d... more The low-energy part of the LINCE facility [1] can be based on a 72.75 MHz normal-conducting RFQ designed to give a 450 keV/u boost for A/Q=7 ions in about 5 m length. The vanes have been electromagnetically designed to accommodate dedicated RF windows producing effective separation of the RFQ modes in an octagonal-shaped resonance chamber [2]. This article outlines the optimization of the quality factor of the cavity by using numerical methods for electromagnetic calculations. Experimental results of RF test carried out on a prototype are also discussed.
Elastic scattering and breakup angular distribution measurements for the systems 6,7Li + p were p... more Elastic scattering and breakup angular distribution measurements for the systems 6,7Li + p were performed at the MAGNEX facility of the Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud (INFN-LNS) in Catania, in the energy range of (2.3–5.4)AMeV. The breakup channel was identified and quantified adopting the algorithm MULTIP.Within this algorithm which is a Monte Carlo simulation code, the history of the breakup fragments can be tagged from the rest frame of the decay nucleus itself to the laboratory frame. Angular distribution data of both elastic scattering and breakup were analyzed under the same theoretical model and the influence of continuum on the elastic channel was investigated.
Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^... more Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^{11}Be on ^{197}Au were measured at energies below (E_{lab}=31.9 MeV) and around (39.6 MeV) the Coulomb barrier. These three channels were unambiguously separated for the first time for reactions of ^{11}Be on a high-Z target at low energies. The experiment was performed at TRIUMF (Vancouver, Canada). The differential cross sections were compared with three different calculations: semiclassical, inert-core continuum-coupled-channels and continuum-coupled-channels ones with including core deformation. These results show conclusively that the elastic and inelastic differential cross sections can only be accounted for if core-excited admixtures are taken into account. The cross sections for these channels strongly depend on the B(E1) distribution in ^{11}Be, and the reaction mechanism is sensitive to the entanglement of core and halo degrees of freedom in ^{11}Be.
Experiments on halo nuclei at energies around the Coulomb barrier can provide good quality data o... more Experiments on halo nuclei at energies around the Coulomb barrier can provide good quality data on elastic, inelastic, breakup and nucleon transfer reactions. This information turns out to be very important to understand the structure and dynamics of these exotic nuclei. In this work we present relevant results obtained from recent scattering experiments of 11Be and 6He on heavy targets
The University of Huelva is presently involved in R&D projects for developing RF accelerator cavi... more The University of Huelva is presently involved in R&D projects for developing RF accelerator cavities. Two types of cavities are presently under design, a prototype of room temperature RFQ injector and a quarter-wave resonator for high intensity heavy-ion linear accelerators. The laboratory is equipped with dedicated test-bench for RF measurements, which includes high-power RF generators, network analyzer, amplifiers and power meters. A clean room is also available having a dedicated space for high-precision mechanical metrology and cavity mounting, together with a vertical cryostat for superconducting cavity test.
Elastic scattering of {sup 7}Be+{sup 28}Si was studied at several near barrier energies for probi... more Elastic scattering of {sup 7}Be+{sup 28}Si was studied at several near barrier energies for probing the energy dependence of the optical potential. Our analysis at 17.2 MeV will be presented in this article and discussed, in terms of Continuum Coupled Channel Calculations (CDCC). This research is part of a long term plan concerning the energy dependence of the optical potential for weakly bound projectiles, at near barrier energies and for probing the potential threshold anomaly. The experiment took place at the EXOTIC facility - Laboratori Nationali di Legnaro (LNL), and refers to an angular distribution measurement, using the detector array EXPADES (Exotic Particle Detection System). Results at 9 MeV (Rutherford region) were also analyzed and were used for estimating the solid angle. Our analysis for other energies is under process.
The low-energy part of the LINCE facility [1] can be based on a 72.75 MHz normal-conducting RFQ d... more The low-energy part of the LINCE facility [1] can be based on a 72.75 MHz normal-conducting RFQ designed to give a 450 keV/u boost for A/Q=7 ions in about 5 m length. The vanes have been electromagnetically designed to accommodate dedicated RF windows producing effective separation of the RFQ modes in an octagonal-shaped resonance chamber [2]. This article outlines the optimization of the quality factor of the cavity by using numerical methods for electromagnetic calculations. Experimental results of RF test carried out on a prototype are also discussed.
Elastic scattering and breakup angular distribution measurements for the systems 6,7Li + p were p... more Elastic scattering and breakup angular distribution measurements for the systems 6,7Li + p were performed at the MAGNEX facility of the Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud (INFN-LNS) in Catania, in the energy range of (2.3–5.4)AMeV. The breakup channel was identified and quantified adopting the algorithm MULTIP.Within this algorithm which is a Monte Carlo simulation code, the history of the breakup fragments can be tagged from the rest frame of the decay nucleus itself to the laboratory frame. Angular distribution data of both elastic scattering and breakup were analyzed under the same theoretical model and the influence of continuum on the elastic channel was investigated.
Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^... more Angular distributions of the elastic, inelastic, and breakup cross sections of the halo nucleus ^{11}Be on ^{197}Au were measured at energies below (E_{lab}=31.9 MeV) and around (39.6 MeV) the Coulomb barrier. These three channels were unambiguously separated for the first time for reactions of ^{11}Be on a high-Z target at low energies. The experiment was performed at TRIUMF (Vancouver, Canada). The differential cross sections were compared with three different calculations: semiclassical, inert-core continuum-coupled-channels and continuum-coupled-channels ones with including core deformation. These results show conclusively that the elastic and inelastic differential cross sections can only be accounted for if core-excited admixtures are taken into account. The cross sections for these channels strongly depend on the B(E1) distribution in ^{11}Be, and the reaction mechanism is sensitive to the entanglement of core and halo degrees of freedom in ^{11}Be.
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Papers by Ismael Martel Bravo