Suchergebnisse

5 pags., 2 figs. -- International Symposium on Nuclear Astrophysics - Nuclei in the Cosmos - IX 25-30 June 2006 CERN ; We have studied 12C in full kinematics via the 10B( 3He,pααα) reaction at 2.45 MeV. In our data we have identified states in 12C from the ground state up to about 18 MeV, with spins ranging from 0 to 4. Due to the very good resolution, we are able to determine properties of these 12C resonances, such as their energy, width, and spin. In this contribution preliminary results from the ongoing analysis is presented. ; This work has been made possible by the CSIC I3P program, and is supported by the European Union under the Sixth framework project EURONS-contract number 506065. ; Peer reviewed

The 9Li + 2H reaction has been investigated at 2.36 MeV/u at the REX-ISOLDE facility. In this Letter we focus on the 10Li + p channel which potentially holds spectroscopic information on the unbound nucleus 10Li. The experimental excitation energy spectrum and angular distribution are compared with CCBA calculations. These calculations clearly support the existence of a low-lying (s) virtual state, with a (negative) scattering length of the order as ∼ 13 - 24 fm and a p1 / 2 resonance with an energy of Er ≃ 0.38 MeV and a width of Γ ≃ 0.2 MeV. ; European Union Fifth Framework HPRI-CT-1999-00018 ; Comisión Interministerial de Investigaciones Científicas FPA2005-02379 y FPA2005-04460

4 pags.; 6 figs.; 1 tab.; Open Access funded by Creative Commons Atribution Licence 4.0 ; © 2015 The Authors. We have observed β+-delayed α and pα emission from the proton-rich nucleus 21Mg produced at the ISOLDE facility at CERN. The assignments were cross-checked with a time distribution analysis. This is the third identified case of βpα emission. We discuss the systematic of beta-delayed particle emission decays, show that our observed decays fit naturally into the existing pattern, and argue that the patterns are to a large extent caused by odd–even effects. ; We acknowledge support from the European Union Seventh Framework through ENSAR (contract no. 262010) and by the Spanish research agency under number FPA2012-32443. ; Peer Reviewed

5 pages, 1 table, 3 figures.-- PACS nrs.: 23.40.Hc; 27.20.+n; 21.10.Hw.-- Printed version published Jun 29, 2009.-- ArXiv available at: http://arxiv.org/abs/0904.4212v1 ; Coincidences between charged particles emitted in the β-decay of 11Li were observed using highly segmented detectors. The breakup channels involving three particles were studied in full kinematics allowing for the reconstruction of the excitation energy of the 11Be states participating in the decay. In particular, the contribution of a previously unobserved state at 16.3 MeV in 11Be has been identified selecting the α + 7He → α + 6He + n channel. The angular correlations between the α particle and the center of mass of the 6He + n system favors spin and parity assignment of 3/2− for this state as well as for the previously known state at 18 MeV. ; This work has been supported by the Spanish Ministerio de Ciencia e Innovación (MICINN), under the projects FPA2007-62170 and CSD2007-00042, the European Union Sixth Framework through RII3-EURONS (contract No. 506065) and the Swedish Knut and Alice Wallenberg Foundation. ; Peer reviewed

4 pages, 2 figures.--PACS nrs.: 21.45.+v; 23.40.–s; 27.20.+n. ; Using beta decays of a clean source of N-13 produced at the IGISOL facility, we have measured the breakup of the C-12 (12.71 MeV) state into three alpha particles with a segmented particle detector setup. The high quality of the data permits solving the question of the breakup mechanism of the 12.71 MeV state, a longstanding problem in few-body nuclear physics. Among existing models, a modified sequential model fits the data best, but systematic deviations indicate that a three-body description is needed. ; This research was supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2000-2005 (Project No. 44875, Nuclear and Condensed Matter Physics Programme at JYFL), by the Spanish Agency CICYT under Contract No. AEN99-1046-C02-02, and by the European Union Fifth Framework Programme ''Improving Human Potential–Access to Research Infrastructure.'' ; Peer reviewed

12 pages, 5 figures, 3 tables.-- PACS nrs.: 23.40.Hc; 27.20.+n.-- Printed version published Sep 15, 2008.-- ArXiv pre-print available at: http://arxiv.org/abs/0806.3025 ; The β-delayed charged particle emission from Li-11 has been studied with emphasis on the three-body nαHe-6 and five-body 2α3n channels from the 10.59 and 18.15 MeV states in Be-11. Monte Carlo simulations using an R-matrix formalism lead to the conclusion that the He-A resonance states play a significant role in the break-up of these states. The results exclude an earlier assumption of a phase-space description of the break-up process of the 18.15 MeV state. Evidence for extra sequential decay paths is found for both states. ; This work has been supported by the Spanish CICYT, under the projects FPA2002-04181-C04-02, FPA2005-02379 and theMEC Consolider project CSD2007-00042, the European Union Sixth Framework through RII3-EURONS (contract No. 506065) and the Swedish Knut and Alice Wallenberg Foundation. M. Madurga acknowledges the support of the Spanish MEC under the FPU program, FPU AP-2004-0002. ; Peer reviewed

5 pages, 2 tables, 3 figures.--PACS nrs.: 23.40.Hc; 27.20.+n. ; The beta decay of O-13 has been studied at the IGISOL facility of the Jyvaskyla accelerator centre (Finland). By developing a low-energy isotope-separated beam of O-13 and using a modern segmented charged-particle detector array an improved measurement of the delayed proton spectrum was possible. Protons with energy up to more than 12 MeV are measured and the corresponding log(ft) values extracted. A revised decay scheme is constructed. The connection to molecular states and the shell model is discussed. ; This work was supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2000–2005 (Project No. 44875, Nuclear and Condensed Matter Physics Programme at JYFL), by the European Union Fifth Framework Programme "Improving Human Potential - Access to Research Infrastructure" contract no. HPRI-CT-1999-00044, by the Spanish CICYT Agency under Project number FPA2002-04181-C04-02, and by the EU-RI3 (Integrated Infrastructure Initiative) under contract no 506065. ; Peer reviewed

4 pages, 3 figures, 1 table.-- PACS nrs.: 21.10.Tg; 23.40.−s; 27.40.+z. ; The Advanced-Time-Delayed method was used to measure lifetimes of the states in Ar-41 populated in the β decay of Cl-41. The nuclei Cl-41 were produced at ISOLDE by 1.4-GeV proton bombardment of a thick UCx target and mass-separated as molecular ions, XeCl+. Our measured half-life of the 167.1-keV state, T(1/2) = 315(15) ps, is significantly lower than the previously measured value of 410(30) ps. We have also determined T(1/2) = 260(80) ps and T(1/2) ≤ 46 ps for the 515.9- and 1867.7-keV states, respectively. These are the shortest lifetimes measured so far with the ultrafast timing method using the new LaBr3(Ce) crystals for γ-ray detection. ; This work was performed as part of an undergraduate research project (ERW) at the Physics Department of the University of Notre Dame. Fast-timing detectors and electronics were provided by the Fast Timing Pool of Electronics. This study was supported in part by the NSF PHY04-57120, Swedish Research Council, BMBF Grant No. 06KY205I, the Alexander von Humboldt Foundation (WBW), Foundation for Polish Science (AK), the European Union Sixth Framework through RII3-EURONS (Contract No. 506065), and the EURTD project TARGISOL (HPRI-CT-2001-50033). ; Peer reviewed

6 pages, 2 figures.-- PACS nrs.: 24.30.Cz, 25.70.Gh.-- Presented at the Zakopane Conference on Nuclear Physics (Zakopane, Poland, Sep. 4–10, 2006). ; The Advanced Time Delayed method has been used to measure the lifetimes of excited states in the exotic nuclei Sb-134, Sb-135 and Te-136 populated in the beta decay of Sb-134, Sb-135 and Te-136, respectively. High purity Sn beams were extracted at the ISOLDE separator using a novel production technique utilizing the molecular SnS+ beams to isolate Sn from contaminating other fission products. Among the new results we have identified the 1/2+ state in Sb-135 and its E2 transition to the lower-lying 5/2+ state was found to be surprisingly collective. This measurement represents also one of the first applications of the LaBr3 scintillator to ultra fast timing. ; This work was supported by the NSF PHY04-57120, NSF PHY-0555366, Swedish Research Council, BMBF grant 06KY205I, the Alexander von Humboldt Foundation (WBW), the European Union Sixth Framework through RII3-EURONS (contract no. 506065) and the EU-RTD project TARGISOL (HPRI-CT-2001-50033). ; Peer reviewed

New experimental data for dissociation of relativistic 17Ne projectiles incident on targets of lead, carbon, and polyethylene targets at GSI are presented. Special attention is paid to the excitation and decay of narrow resonant states in 17Ne. Distributions of internal energy in the 15O +p +pthree-body system have been determined together with angular and partial-energy correlations between the decay products in different energy regions. The analysis was done using existing experimental data on 17Ne and its mirror nucleus 17N. The isobaric multiplet mass equation is used for assignment of observed resonances and their spins and parities. A combination of data from the heavy and light targets yielded cross sections and transition probabilities for the Coulomb excitations of the narrow resonant states. The resulting transition probabilities provide information relevant for a better understanding of the 17Ne structure. ; This project is supported by NAVI, GSI-TU Darmstadt cooperation, HIC for FAIR, EMMI and BMBF. C.A.B. acknowledges support from the U.S. NSF Grant No. 1415655, and U.S. DOE grant No. DEFG02- 08ER41533. The work was also supported by the Spanish government grant FPA2012-32443 and the Swedish Research Council ; SI