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Utilizing a polymer-based radiation shield offers lightweight, low cost, non-toxic compared to lead and solution for eliminating generated secondary neutrons. Incorporating silicon (i.e., one of the most abundant elements) in new applications, such as shielding, would have an impact on the economy and industry. In this study, seven potential shielding materials, composed of silicon, silicon carbide, and boron carbide embedded ethylene vinyl acetate (EVA) copolymers, are proposed. The shielding performance of these composite materials, including the attenuation coefficients (µ), the mass attenuation coefficients (µm), the half value layer (HVL), the mean free path (MFP), and the radiation protection efficiency (RPE) were examined using photon beams. Measured µm were verified against the calculated values. The averaged agreement was within ±7.4% between the experimental measurements and the theoretical calculation results. The HVL and MFP measured values for the polymer composites were lower than that for the pure EVA polymer, indicating the fillers in the polymers enhanced the shielding performance. The EVA + SiC (30%) and EVA + Si (15%) + B4C (15%) composites required the lowest thickness to stop 50% of the incident photons. The evaluation of experimental results of the RPE revealed that the polymer composites containing SiC (30%), Si (15%) + B4C (15%), or SiC (15%) + B4C (15%) succeeded in blocking 90–91% of X-rays at nearly 80 keV. However, a thicker shield of the proposed composite materials or combined layers with other high-Z materials could be used for higher energies.

International audience; Characteristics of the primary fissioning fragments produced from the ^129Xe+ ^natSn reaction at E = (18–25) A MeV have been obtained. Correlation function method was improved to extract the multiplicity of the light charged particles that evaporated from the primary fissioning fragments. These multiplicities, after the subtraction of the background contribution, was used to reconstruct the mass and atomic number of the primary fissioning fragments. The mean velocity of these particles is used to build their kinetic energies, which required reconstructing the excitation energy of the primary fissioning fragments.

8 pags., 10 figs., 3 tabs., The Borromean drip-line nucleus Ne-17 has been suggested to possess a two-proton halo structure in its ground state. In the astrophysical rp-process, where the two-proton capture reaction O-15(2p,gamma) Ne-17 plays an important role, the calculated reaction rate differs by several orders of magnitude between different theoretical approaches. To add to the understanding of the Ne-17 structure we have studied nuclear and electromagnetic dissociation. A 500 MeV/u Ne-17 beam was directed toward lead, carbon, and polyethylene targets. Oxygen isotopes in the final state were measured in coincidence with one or two protons. Different reaction branches in the dissociation of Ne-17 were disentangled. The relative populations of s and d states in F-16 were determined for light and heavy targets. The differential cross section for electromagnetic dissociation (EMD) shows a continuous internal energy spectrum in the three-body system O-15 + 2p. The Ne-17 EMD data were compared to current theoretical models. None of them, however, yields satisfactory agreement with the experimental data presented here. These new data may facilitate future development of adequate models for description of the fragmentation process., This project is supported by NAVI, GSI-TU Darmstadt cooperation, HIC for FAIR, EMMI, and BMBF and from DFG through Grant No. SFB1245 and from BMBF via Project No. 05P15RDFN1, and from the Spanish Ministry by research grant FPA2015-64969-P. C.A.B. acknowledges support by the US DOE Grant No. DE-FG02-08ER41533 and the US NSF Grant No. 1415656.

R. Reifarth et al: ; 12 págs.; 9 figs.; Open Access funded by Creative Commons Atribution Licence 3.0 ; Nuclear Physics in Astrophysics VI (NPA6), The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process ow and r-process -decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will oer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes., This project was supported by the HGF Young Investigators Project VH-NG-327, EMMI, H4F, HGS-HIRe, JINA, NAVI, DFG and ATHENA.

In the present work, the differential cross sections for small-angle proton elastic scattering on the 12,14 Be nuclei were measured in inverse kinematics, using secondary radioactive beams with energies near 700 MeV/u produced with the fragment separator FRS at GSI. The main part of the experimental setup was the active target IKAR, which was used simultaneously as a target and a detector for the recoil protons. Auxiliary detectors for projectile tracking and isotope identification completed the setup. The measured differential cross sections were analyzed using the Glauber multiple-scattering theory. For the evaluation of the data several phenomenological nuclear-matter density parametrizations and a sum of Gaussian parametrization were used. The nuclear-matter radii and radial density distributions of the isotopes 12,14 Be were deduced. Extended nuclear-matter density distributions were observed in both isotopes, and the halo structure of 14 Be was confirmed. The results were also compared with microscopic few-body and fermionic molecular dynamics model calculations concerning the structure of these neutron-rich nuclei.

We present experimental results on the electromagnetic excitation of neutron-rich nickel isotopes, making use of the (RB)-B-3-LAND setup at GSI. Exotic beams were produced at approximately 500 MeV/u and their reactions were studied in inverse kinematics. Integral cross sections for Ni-58 are discussed and compared to previous data, providing a validation of our experimental method. The El excitation-energy distribution of the unstable Ni-68 is presented as well, showing an excess in cross section in the 1n decay channel when compared only with a typical Giant Dipole Resonance.

We report on a new experimental setup for the investigation of proton induced reactions on exotic nuclei in inverse kinematics. It was installed and successfully used in the scattering study of intermediate-energy protons ( ∼ 700 MeV / u ) on neutron-rich nuclei 6,8He produced with the FRagment Separator (FRS) at the GSI facility, Darmstadt. A new pure liquid-hydrogen target was successfully adapted allowing to obtain low-background data as compared to commonly used (CH2)n targets. Absolute differential cross-sections for elastic (p,6,8He) scattering were obtained at angles corresponding to 0.05 ⩽ | t | ⩽ 0.125 (GeV/c)2 of the four-momentum transfer squared (−t) leading to the first diffraction minimum and spanning more than two orders of magnitude. They complement an earlier measurement at smaller angles 0.0025 ⩽ | t | ⩽ 0.05 (GeV/c)2 performed at the same energy with an active target. Both data sets agree well in the overlap region t ≈ 0.05 (GeV/c)2 and enable a refined and comparative study of the radial distribution of the nuclear matter density.

This contribution presents some results from the first feasibility measurement performed at GSI using a 350 MeV/nucleon 136 Xe beam and a Hydrogen gas-jet target. In this feasibility study, one element of every possible detection part of the future EXL detection system was investigated. In addition, simulation results for EXL setup will be presented.

A method is presented for the detection of charged particles emitted in the b-decay of exotic nuclei. Direct implantation of radioactive nuclei in a very thin double-sided silicon strip detector is now feasible thanks to the advances in the production and post-acceleration of ISOL beams. The high degree of pixelazation, and consequently the small active volume of the detector, and the precise energy of the radioactive ion beam are the key features of the method. Among the advantages of the method are a good precision of the overall normalization and a reduction of the background due to b-radiation. Several developments are described in the present paper. The detection threshold at low energies is determined using pulsed signals. An alternative energy calibration for the decay events, free from any dead layer effects can be performed by implanting radioactive ions decaying to known narrow resonances, e.g. 20Na. Time and position correlations in a small detection volume can be used to identify possible different decay channels. An overview of precision measurements using this technique is given to prove the strength of the method. ispartof: Nuclear Instruments & Methods in Physics Research B vol:266 issue:19 pages:4652-4656 ispartof: location:FRANCE, Deauville status: published

The unbound isotopes 10Li, 12Li and 13Li have been observed after nucleon-knockout reactions at relativistic energies with 11Li and 14Be beams impinging on a liquid hydrogen target. The channels , and were analysed in the ALADIN-LAND setup at GSI. The 10Li data confirm earlier findings, while the 12Li and 13Li nuclei were observed for the first time. The relative-energy spectrum shows that the ground state of 12Li can be described as a virtual s-state with a scattering length of -13.7(1.6) fm. A broad energy spectrum was found for the channel. Based on the assumption that the relative-energy spectrum is dominated by a correlated background presumably stemming from initial correlations in the 14Be ground-state, evidence for a 13Li resonance at 1.47(31) MeV above the threshold with a width around 2 MeV has been found.

In a series of experiments at the SISSI/LISE3 facility of GANIL conducted between 1999 and 2004, we have collected decay information for proton-rich nuclei between {sup 36}Ca and {sup 56}Zn. The data allowed us to study the decay properties of 26 nuclei. The main experimental information obtained for all nuclei is their {beta}-decay half-life and their total {beta}-delayed proton emission branching ratio. For many nuclei, individual proton groups and {gamma} rays were identified and allowed us to establish first partial decay schemes for some of the nuclei studied. In addition, mass-excess values have been determined for some of the nuclei by means of the isobaric multiplet mass equation. For {sup 50}Ni, the decay via {beta}-delayed two-proton emission could be tentatively identified. The decay of {sup 49}Ni allowed for the first time to identify the first 2{sup +} state in {sup 48}Fe. The experimental data are confronted to model predictions for the half-life and the mass-excess values.

J. Marganiec et al.; 9 pags.; 11 figs.; 2 tabs., © 2015, SIF, Springer-Verlag Berlin Heidelberg. Two-proton decay of the unbound Tz = -2 nucleus 16Ne , produced in one-neutron knockout from a 500 MeV/u 17Ne beam, has been studied at GSI. The ground state, at a resonance energy 1.388(15) MeV, (Γ = 0.082(15) MeV) above the 14O +p+p threshold, and two narrow resonances at Er = 3.220(46) MeV and 7.57(6) MeV have been investigated. A comparison of the energy difference between the first excited 2+ state and the 0+ ground state in 16Ne with its mirror nucleus 16C reveals a small Thomas-Ehrman shift (TES) of +70(46) keV. A trend of the TES for the T = 2 quintet is obtained by completing the known data with a prediction for 16F obtained from an IMME analysis. The decay mechanisms of the observed three resonances were revealed from an analysis of the energy and angular correlations of the 14O +p+p decay products. The ground state decay can be considered as a genuine three-body (democratic) mode and the excited states decay sequentially via states in the intermediate nucleus 15F , the 3.22 MeV state predominantly via the 15F ground-state resonance, while the 7.57 MeV state decays via the 5/2+ resonance in 15F at 2.8 MeV above the 14O +p+p threshold. Further, from an analysis of angular correlations, the spin-parity of the 7.57 MeV state has been determined as IП = 2+ and assigned as the third 2+ state in 16Ne based on a comparison with 16C., This work is partly supported by the Helmholtz International Center for FAIR within the framework of the LOEWE program launched by the State of Hesse, by the German Federal Ministry for Education and Research (BMBF), EU(EURONS), ExtreMe Matter Institute EMMI, GSI-TU Darmstadt cooperation, Nuclear Astrophysics Virtual Institutes NAVI. Financial support from the Swedish Research Council, the Spanish grants FPA-2010-17142, MICCIN FPA2009-14604-C02-01, FPA2012- 39404-C02-01and MINECO FPA 2012-32443 are also acknowledged. One of us (BJ) is a Helmholtz International Fellow

This paper presents the results of experimental investigations of ( p , p n ) , ( p , p α ) and ( p , p 6 He) reactions with relativistic 6 He and 8 He beams impinging on a hydrogen target. Information on the structure of extremely neutron-rich nuclei was obtained by using the unique characteristic of quasi-free scattering processes and inverse kinematics. For the first time, momentum distributions of complex clusters inside 6 He and 8 He were measured. Spectroscopic factors for valence neutrons, α - and 6 He clusters were deduced from the experimental data. They demonstrate that the filling of the p 1 2 shell is the essential feature of the 8 He structure. It is shown that the 8 He cluster structure can be considered as a 6 He core plus two valence neutrons.

We present a method for the detection of charged particles. emitted following beta decay, that allows to reduce the background due to beta radiation and thus to facilitate separation of the delayed-particle events, The isotopes of interest are implanted into a highly segmented double-sided silicon strip detector, resulting in excellent precision on the overall normalisation. The characteristics of the detector and the particle signatures are discussed, This method can be applied to a variety of systems close to the proton and neutron driplines. it region which the recent availability of post-accelerated radioactive beams has opened up for study. To demonstrate this, we measured the branching ratio of He-6 beta decay into the alpha + d two-body continuum of Li-6. We obtained it Value of(1.7 +/- 04) x 10(-6) for energies x + d above 525 keV. (c) 2005 Elsevier B.V. All rights reserved.

The very neutron-deficient 91,92,93Rh and 90,91Ru nuclei were produced in 58Ni(36,40Ar, xn yp) fusion-evaporation reactions. Reaction products leaving the target were stopped in a gas cell and selectively laser ionised before mass separation using the LISOL setup. Data were collected in singles and coincidence formats to investigate $\beta$ -delayed and isomeric $\gamma$ decays. Ground-state decays of 91,93 Rh to excited states in the daughter nucleus were identified for the first time and the decay schemes of 90,91 Ru were expanded. The low-spin isomeric decay of 92Rh was identified for the first time and detail added to the decay scheme of the known high-spin state. Results are discussed in terms of comparison with shell model calculations. $\beta$ -delayed proton activity in the lighter 90Rh and 89Ru isotopes was also investigated and upper limits for this decay mode in these two nuclei have been included.

We report on the first observation of the unbound proton-rich nucleus 15Ne. Its ground state and first excited state were populated in two-neutron knockout reactions from a beam of 500 MeV/u 17Ne. The 15Ne ground state is found to be unbound by 2.522(66) MeV. The decay proceeds directly to 13O with simultaneous two-proton emission. No evidence for sequential decay via the energetically allowed 2- and 1- states in 14F is observed. The 15Ne ground state is shown to have a strong configuration with two protons in the (sd) shell around 13O with a 63(5)% (1s1/2)2 component.

F. Wamers et al.; 4 pags.; 2 figs. Open Access funded by Creative Commons Atribution Licence 2.0, We have studied one-proton-removal reactions of about 500 MeV/u17Ne beams on a carbon target at the R3B/LAND setup at GSI by detecting beam-like 15Op and determining their relative-energy distribution. We exclusively selected the removal of a 17Ne halo proton, and the Glauber-model analysis of the 16F momentum distribution resulted in an s 2 contribution in the 17Ne ground state of about 40 %. C Owned by the authors, published by EDP Sciences, 2014, This work was supported by the Alliance Program of the Helmholtz Association (HA216/EMMI), by the German Federal Ministry for Education and Research (BMBF) (project 05P12RDFN8) by HIC for FAIR, by Eurons (European Commission contract no. 506065), and by GSI.

The E1 strength distribution in Ni68 has been investigated using Coulomb excitation in inverse kinematics at the RB3-LAND setup and by measuring the invariant mass in the one- and two-neutron decay channels. The giant dipole resonance and a low-lying peak (pygmy dipole resonance) have been observed at 17.1(2) and 9.55(17) MeV, respectively. The measured dipole polarizability is compared to relativistic random phase approximation calculations yielding a neutron-skin thickness of 0.17(2) fm. A method and analysis applicable to neutron-rich nuclei has been developed, allowing for a precise determination of neutron skins in nuclei as a function of neutron excess.

Acta physica Polonica / B 45(2), 229 - 234 (2014). doi:10.5506/APhysPolB.45.229, Published by Inst. of Physics, Jagellonian Univ., Cracow

6th Nuclear Physics in Astrophysics Conference (NPA), Lisbon, Portugal, 19 May 2013 - 24 May 2013; Journal of physics / Conference Series 665, 012046 (2016). doi:10.1088/1742-6596/665/1/012046, Published by IOP Publ., Bristol

Results are presented from a one-neutron knockout experiment at relativistic energies of $ \approx 420 A$ MeV on 51-55Sc using the GSI Fragment Separator as a two-stage magnetic spectrometer and the MINIBALL array for gamma-ray detection. Inclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the contributions corresponding to knockout from the $ \nu p_{1/2}$ , $ \nu p_{3/2}$ , (L = 1 and $ \nu f_{7/2}$ , $ \nu f_{5/2}$ (L = 3 neutron orbitals. The observed L = 1 and L = 3 contributions are compared with theoretical cross-sections using eikonal knockout theory and spectroscopic factors from shell model calculations using the GXPF1A interaction. The measured inclusive knockout cross-sections generally follow the trends expected theoretically and given by the spectroscopic strength predicted from the shell model calculations. However, the deduced L = 1 cross-sections are generally 30-40% higher while the L = 3 contributions are about a factor of two smaller than predicted. This points to a promotion of neutrons from the $ \nu f_{7/2}$ to the $ \nu p_{3/2}$ orbital indicating a weakening of the N = 28 shell gap in these nuclei. While this is not predicted for the phenomenological GXPF1A interaction such a weakening is predicted by recent calculations using realistic low-momentum interactions $ V_{low k}$ obtained by evolving a chiral N3LO nucleon-nucleon potential.

6th Nuclear Physics in Astrophysics Conference (NPA), Lisbon, Portugal, 19 May 2013 - 24 May 2013; Journal of physics / Conference Series 665, 012034 (2016). doi:10.1088/1742-6596/665/1/012034, Published by IOP Publ., Bristol

Exotic Ni isotopes have been measured at the R3B-LAND setup at GSI in Darmstadt, using Coulomb excitation in inverse kinematics at beam energies around 500 MeV/u. As the experimental setup allows kinematically complete measurements, the excitation energy was reconstructed using the invariant mass method. The GDR and additional low-lying strength have been observed in 68Ni, the latter exhausting 4.1(1.9)% of the E1 energy-weighted sum rule. Also, the branching ratio for the non-statistical decay of the excited 68Ni nuclei was measured and amounts to 24(4)%., Comment: 11 pages, 7 figures. Invited Talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS)

The aim of this work is to develop a 3D gamma camera with high position resolution and sensitivity relying on both distance/absorption and Compton scattering techniques and without using any passive collimation. The proposed gamma camera is simulated in order to predict its performance using the full benefit of Geant4 features that allow the construction of the needed geometry of the detectors, have full control of the incident gamma particles and study the response of the detector in order to test the suggested geometries. Three different geometries are simulated and each configuration is tested with three different scintillation materials (LaBr3, LYSO and CeBr3).

The investigation of light-ion reactions with exotic beams in inverse kinematics gives access to a comprehensive range of nuclear structure information in the region far off stability. The future FAIR facility at CSI will provide new opportunities to extend and advance these investigations. The present paper will focus on the results of the first feasibility experiment for the EXL project in which we used a stored (136)Xe beam with E = 350 MeV/nucleon interacting with an internal hydrogen gas-jet target at the ESR storage ring of GSI. In this experiment we made use of at least one element of every detector part of the future experimental setup. Selected results from this measurement will be presented. (C) 2011 Elsevier B.V. All rights reserved.

We measured the deuteron-emission branch of the beta decay of the halo nucleus He-6 using the technique of implantation into a highly segmented silicon detector. The method, used here for the first time with a beam of He-6 ions, ensures precise normalization; the value obtained for the branching ratio is B=(1.65 +/- 0.10)x10(-6) (6% error). The summed energy spectra of the emitted alpha and d particles has also been measured. The results allow us to compare calculations from various models, potentially setting strong constraints on the precision required for the description of the He-6 ground-state wave function.

A concentration of dipole strength at energies below the giant dipole resonance was observed in neutron-rich nuclei around Sn-132 in an experiment using the FRS-LAND setup. This so-called "pygmy" dipole strength can be related to the parameters of the symmetry energy and to the neutron skin thickness on the grounds of a relativistic quasiparticle random-phase approximation. Using this ansatz and the experimental findings for Sn-130 and 132 Sri, we derive a value of the symmetry energy pressure of (p) over bar (0) = 2.2 +/- 0.5 MeV/fm(3). Neutron skin thicknesses of R-n-R-p = 0.23 +/- 0.03 fm and 0.24 +/- 0.03 fm for Sn-130 and Sn-132, respectively, have been determined. Preliminary results on Ni-68 from a similar experiment using an improved setup indicate an enhanced cross section at low energies, while the results for Ni-58 are in accordance with results from photoabsorption measurements.

6 pages, 4 figures.-- PACS nrs.: 21.60.Cs; 23.20.Lv; 24.50.+g; 25.60.Gc; 27.40.+z.-- Printed version published May 4, 2009.-- ArXiv pre-print available at: http://arxiv.org/abs/0810.3157, Results are presented from a one-neutron knockout reaction at relativistic energies on Ti-56 using the GSI FRS as a two-stage magnetic spectrometer and the Miniball array for gamma-ray detection. Inclusive and exclusive longitudinal momentum distributions and cross-sections were measured enabling the determination of the orbital angular momentum of the populated states. First-time observation of the 955(6) keV vp(3/2)(-1)-hole state in Ti-55 is reported. The measured data for the first time proves that the ground state of Ti-55 is a 1/2(−) state, in agreement with shell-model calculations using the GXPF1A interaction that predict a sizable N=34 gap in Ca-54., This work was supported by the BMBF under contract 06MT238, by the DFG cluster of excellence "Origin and Structure of the Universe"(http://www.universe-cluster.de) and by the European Commission within the Sixth Framework Programme through I3-EURONS (contract No. RII3-CT-2004-506065). J. Tostevin acknowledges support from the United Kingdom Science and Technology Facilities Council (STFC) under Grant No. EP/D003628. T. Nilsson acknowledges the support of the Knut and Alice Wallenberg Foundation, Sweden. R. Kanungo gratefully acknowledges the support of the AvH foundation. B.A. Brown acknowledges support from NSF grant PHY-0758099.

The nuclei Ca-47 and Ti-55 were populated in one-neutron knock-out reactions at relativistic energies. Momentum distributions of the residual nuclei as well as gamma-ray spectra were measured at the GSI fragment separator (FRS). Preliminary results of the ongoing analysis including cross sections and spin/parity assignments are presented.

Neutron rich Zinc isotopes, including the N = 50 nucleus 80Zn, were produced and post-accelerated at the Radioactive Ion Beam (RIB) facility REX-ISOLDE (CERN). Low-energy Coulomb excitation was induced on these isotopes after post-acceleration, yielding B(E2) strengths to the first excited 2+ states. For the first time, an excited state in 80Zn was observed and the 21+ state in 78Zn was established. The measured B(E2,21+->01+) values are compared to two sets of large scale shell model calculations. Both calculations reproduce the observed B(E2) systematics for the full Zinc isotopic chain. The results for N = 50 isotones indicate a good N = 50 shell closure and a strong Z = 28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus 78Ni. Book subtitle: FINUSTAR 2 ispartof: pages:291-295 ispartof: AIP Conference Proceedings vol:1012 issue:1 pages:291-295 ispartof: Frontiers In NUclear STructure, Astrophysics and Reactions: FINUSTAR location:Kos, Greece date:10 Sep - 14 Sep 2007 status: published

Neutron-rich, radioactive Zn isotopes were investigated at the Radioactive Ion Beam facility REX-ISOLDE (CERN) using low-energy Coulomb excitation. The energy of the 2(1)+ state in 78Zn could be firmly established and for the first time the 2+ --> 0(1)+ transition in 80Zn was observed at 1492(1) keV. B(E2,2(1)+ --> 0(1)+) values were extracted for (74,76,78,80)Zn and compared to large scale shell model calculations. With only two protons outside the Z=28 proton core, 80Zn is the lightest N=50 isotone for which spectroscopic information has been obtained to date. Two sets of advanced shell model calculations reproduce the observed B(E2) systematics. The results for N=50 isotones indicate a good N=50 shell closure and a strong Z=28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus 78Ni.

In an experiment at the SISSI/LISE3 facility of GANIL, we have studied the decay of the two proton-rich nuclei $^{45}\mathrm{Fe}$ and $^{48}\mathrm{Ni}$. We identified 30 implantations of $^{45}\mathrm{Fe}$ and observed for the second time four implantation events of $^{48}\mathrm{Ni}$. In 17 cases, $^{45}\mathrm{Fe}$ decays by two-proton emission with a decay energy of 1.154(16) MeV and a half-life of ${T}_{1/2}={1.6}_{\ensuremath{-}0.3}^{+0.5}$ ms. The observation of $^{48}\mathrm{Ni}$ and of its decay allows us to deduce a half-life of ${T}_{1/2}={2.1}_{\ensuremath{-}0.7}^{+2.1}$ ms. One out of four decay events is completely compatible with two-proton radioactivity and may therefore indicate that $^{48}\mathrm{Ni}$ has a two-proton radioactivity branch. We discuss all information now available on two-proton radioactivity for $^{45}\mathrm{Fe}$ and $^{48}\mathrm{Ni}$ and compare it to theoretical models.

We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient γ spectrometer MINIBALL. Using Mg-30 ions accelerated to an energy of 2.25 MeV/u together with a thin Ni-nat target, Coulomb excitation of the first excited 2(+) states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation γ-ray yields the B(E2;0(gs)(+)R 2(1)(+)) value of Mg-30 was determined to be 241(31)e(2) fm(4). Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope Mg-30 resides outside the "island of inversion."

NESTER; International audience; In an experiment performed at the LISE3 facility of GANIL, the isotope 54Zn and its decay via two-proton emission were observed for the first time. In addition, preliminary results indicate that three implantation events of 48Ni were observed. One of the associated decay events is compatible with a two-proton emission. New data on the decay of 45Fe and its two-proton branch were recorded at the same time. The results for 54Zn are compared to theory.

After the successful commissioning of the Radioactive beam EXperiment (REX) at ISOLDE (CERN) in 2002, first physics experiments were performed in 2003 which focussed on the neutron-rich Mg isotopes in the vicinity of the “island of inversion”. After introducing the REX facility and the modern γ spectrometer MINIBALL first preliminary results will be presented showing the high potential and physics opportunities offered by this new radioactive beam facility.

The study of neutron-rich light nuclei near the drip line has attracted much attention as they exhibit a particular nuclear structure, namely an extended distribution of the valence neutrons surrounding a compact core. Recently the elastic proton scattering from 6,8He and 8,9,11Li at 700 MeV/u using an inverse kinematics was successfully measured at GSI [1,2]. A high-pressure hydrogen-filled ionization chamber was used as the target and a proton detector. The previous experiments were performed in the small range 0.002 ≤| t |≤ 0.05 (GeV/c)2 of the four-momentum transfer squared t and have yielded valuable information on the nuclear sizes and radial structure of nuclear matter density distributions with the aid of the Glauber multiple scattering theory. Recently, a novel experimental approach has been accomplished with the aim to deduce the differential p 6,8He cross sections in the t-range 0.05 ≤| t |≤ 0.25 (GeV/c)2 close to the expected first diffraction minimum.

Neutron-rich light nuclei near the neutron drip line have attracted much attention in recent years as they feature a particular nuclear structure, namely an extended distribution (so-called halo) of the valence neutrons surrounding a compact nuclear core. Elastic proton scattering is known as a suitable technique for exploring the nuclear matter distributions in the stable nuclei. It was successfully employed at GSI also for the radioactive nuclei 6,8He and 8,9,11Li [1–3]. The experimental technique of inverse kinematics was applied using radioactive beams with energies near 700 MeV/u. The elastic differential cross section for small-angle scattering (3° ≤ θCM ≤ 10°) was deduced from the data taken with the ionization chamber IKAR, as an active target, and a forward spectrometer. The method has been demonstrated to be very effective for obtaining valuable information on the nuclear matter distribution in the halo nuclei under investigation, such as 6He, 8He and 11Li. The previous measurements at small momentum transfer have been highly sensitive on the nuclear sizes and the radial distributions of the nuclear matter density. Recently, a novel experimental approach has been accomplished with the aim to deduce the differential p6,8He cross sections for larger angles (10≤ ± θCM ≤ 30°) that correspond to a higher momentum transfer which covers the region of the first diffraction minimum.

The investigation of light-ion induced direct reactions in inverse kinematics, using stored and cooled radioactive beams, interacting with internal H, He, etc. gas-jet targets, bears a large potential for nuclear structure and astrophysics studies on exotic nuclei. An extended research project EXL has been accepted for the future facility FAIR in Darmstadt, Germany. In order to explore the experimental conditions for measurements planned at FAIR, a first test experiment for proving the feasibility of the EXL concept was performed.

Absolute differential cross-sections for elastic p 6He and p 8He scattering were measured in inverse kinematics with secondary beams. In order to supplement data taken for small-angle scattering, differential cross-sections for higher momentum transfer were measured using liquid hydrogen target. Both data sets were analyzed together. They have permitted to deduce the radial shape of the nuclear matter distributions and the root-mean-square radii with the help of Glauber theory. In addition to a phenomenological analysis, used already in the previous work, a model-independent analysis with a help of a Sum-Of-Gaussians (SOG) method has been performed. The experimental p 6;8He elastic scattering cross-sections have also been compared with the predictions from various theoretical nuclear models.

The appearance of the pygmy-dipole-resonance is a recently observed phenomenon that can be related to neutron-matter properties. Its study can be a tool to determine the nuclear symmetry-energy parameters and thus can contribute constraining neutron star models. We present the ( γ,n ) cross sections for different Ni isotopes obtained from a measurement in inverse kinematics at about 500 MeV/u in the LAND reaction setup at GSI. The question of the disentanglement of the Coulomb and nuclear contributions is addressed.

Physics letters / B 759, 200 - 205 (2016). doi:10.1016/j.physletb.2016.05.073, Published by North-Holland Publ., Amsterdam

An experiment was performed using the FRS-LAND setup at GSI to study the dipole strength distributions above neutron separation threshold for neutron-rich Ni isotopes. Measurements, using the same experimental setup, were also carried out to extract single particle occupancies via knockout reactions to investigate the structure and magicity of the neutron-rich Ni isotopes. The status of the data analysis and preliminary results are presented.