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Sample records for neutron-rich radioactive ion

  1. Reactions with fast radioactive beams of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Aumann, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)

    2005-11-01

    The neutron dripline has presently been reached only for the lightest nuclei up to the element oxygen. In this region of light neutron-rich nuclei, scattering experiments are feasible even for dripline nuclei by utilizing high-energy secondary beams produced by fragmentation. In the present article, reactions of high-energy radioactive beams will be exemplified using recent experimental results mainly derived from measurements of breakup reactions performed at the LAND and FRS facilities at GSI and at the S800 spectrometer at the NSCL. Nuclear and electromagnetically induced reactions allow probing different aspects of nuclear structure at the limits of stability related to the neutron-proton asymmetry and the weak binding close to the dripline. Properties of the valence-neutron wave functions are studied in the one-neutron knockout reaction, revealing the changes of shell structure when going from the beta-stability line to more asymmetric loosely bound neutron-rich systems. The vanishing of the N=8 shell gap for neutron-rich systems like {sup 11}Li and {sup 12}Be, or the new closed N=14, 16 shells for the oxygen isotopes are examples. The continuum of weakly bound nuclei and halo states can be studied by inelastic scattering. The dipole response, for instance, is found to change dramatically when going away from the valley of stability. A redistribution of the dipole strength towards lower excitation energies is observed for neutron-rich nuclei, which partly might be due to a new collective excitation mode related to the neutron-proton asymmetry. Halo nuclei in particular show strong dipole transitions to the continuum at the threshold, being directly related to the ground-state properties of the projectile. Finally, an outlook on future experimental prospects is given. (orig.)

  2. Cluster-transfer reactions with radioactive beams: a spectroscopic tool for neutron-rich nuclei

    CERN Document Server

    AUTHOR|(CDS)2086156; Raabe, Riccardo; Bracco, Angela

    In this thesis work, an exploratory experiment to investigate cluster-transfer reactions with radioactive beams in inverse kinematics is presented. The aim of the experiment was to test the potential of cluster-transfer reactions at the Coulomb barrier, as a possible mean to perform $\\gamma$ spectroscopy studies of exotic neutron-rich nuclei at medium-high energies and spins. The experiment was performed at ISOLDE (CERN), employing the heavy-ion reaction $^{98}$Rb + $^{7}$Li at 2.85 MeV/A. Cluster-transfer reaction channels were studied through particle-$\\gamma$ coincidence measurements, using the MINIBALL Ge array coupled to the charged particle Si detectors T-REX. Sr, Y and Zr neutron-rich nuclei with A $\\approx$ 100 were populated by either triton- or $\\alpha$ transfer from $^{7}$Li to the beam nuclei and the emitted complementary charged fragment was detected in coincidence with the $\\gamma$ cascade of the residues, after few neutrons evaporation. The measured $\\gamma$ spectra were studied in detail and t...

  3. Theoretical study on production of heavy neutron-rich isotopes around the N=126 shell closure in radioactive beam induced transfer reactions

    Directory of Open Access Journals (Sweden)

    Long Zhu

    2017-04-01

    Full Text Available In order to produce more unknown neutron-rich nuclei around N=126, the transfer reactions 136Xe + 198Pt, 136–144Xe + 208Pb, and 132Sn + 208Pb are investigated within the framework of the dinuclear system (DNS model. The influence of neutron excess of projectile on production cross sections of target-like products is studied through the reactions 136,144Xe + 208Pb. We find that the radioactive projectile 144Xe with much larger neutron excess is favorable to produce neutron-rich nuclei with charge number less than the target rather than produce transtarget nuclei. The incident energy dependence of yield distributions of fragments in the reaction 132Sn + 208Pb are also studied. The production cross sections of neutron-rich nuclei with Z=72–77 are predicted in the reactions 136–144Xe + 208Pb and 132Sn + 208Pb. It is noticed that the production cross sections of unknown neutron-rich nuclei in the reaction 144Xe + 208Pb are at least two orders of magnitude larger than those in the reaction 136Xe + 208Pb. The radioactive beam induced transfer reactions 139,144Xe + 208Pb, considering beam intensities proposed in SPIRAL2 (Production System of Radioactive Ion and Acceleration On-Line project as well, for production of neutron-rich nuclei around the N=126 shell closure are investigated for the first time. It is found that, in comparison to the stable beam 136Xe, the radioactive beam 144Xe shows great advantages for producing neutron-rich nuclei with N=126 and the advantages get more obvious for producing nuclei with less charge number.

  4. Probing the nuclear symmetry energy with heavy-ion reactions induced by neutron-rich nuclei

    Institute of Scientific and Technical Information of China (English)

    CHEN Lie-wen; KO Che-Ming; LI Bao-an; YONG Gao-chan

    2007-01-01

    Heavy-ion reactions induced by neutron-rich nuclei provide a unique means to investigate the equation of state of isospin-asymmetric nuclear matter,especially the density dependence of the nuclear symmetry energy.In particular,recent analyses of the isospin diffusion data in heavyion reactions have already put a stringent constraint on thenuclear symmetry energy around the nuclear matter saturation density.We review this exciting result and discuss its implications on nuclear effective interactions and the neutron skin thickness of heavy nuclei.In addition,we also review the theoretical progress on probing the high density behaviors of the nuclear symmetry energy in heavy-ion reactions induced by high energy radioactive beams.

  5. Gamma-ray spectroscopy of neutron-rich products of heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Janssens, R.V.F.; Ahmad, I. [and others

    1995-08-01

    Thick-target {gamma}{gamma} coincidence techniques are being used to explore the spectroscopy of otherwise hard-to-reach neutron-rich products of deep-inelastic heavy ion reactions. Extensive {gamma}{gamma} coincidence measurements were performed at ATLAS using pulsed beams of {sup 80}Se, {sup 136}Xe, and {sup 238}U on lead-backed {sup 122,124}Sn targets with energies 10-15% above the Coulomb barrier. Gamma-ray coincidence intensities were used to map out yield distributions with A and Z for even-even product nuclei around the target and around the projectile. The main features of the yield patterns are understandable in terms of N/Z equilibration. We had the most success in studying the decays of yrast isomers. Thus far, more than thirty new {mu}s isomers in the Z = 50 region were found and characterized. Making isotopic assignments for previously unknown {gamma}-ray cascades proves to be one of the biggest problems. Our assignments were based (a) on rare overlaps with radioactivity data, (b) on the relative yields with different beams, and (c) on observed cross-coincidences between {gamma} rays from light and heavy reaction partners. However, the primary products of deep inelastic collisions often are sufficiently excited for subsequent neutron evaporation, so {gamma}{gamma} cross-coincidence results require careful interpretation.

  6. Test of high density UC targets development at Gatchina for neutron rich radioactive beam facilities

    CERN Document Server

    Lhersonneau, G; Lanchais, A; Rizzi, V; Tecchio, L.B; Bajeat, O; Essabaa, S; Lau, C; Cheikh Mhamed, M; Roussière, B; Barzakh, A.E; Fedorov, D.V; lonan, A.M; lvanov, V.S; Mezilev, K.A; Moroz, F.V; Orlov, S.YU; Panteleevc, V.N; Volkovc, YU.M; Dubois, M; Eléon, C; Gaubert, G; Jardin, P; Leroy, R; Saint Laurent, M.G; Villari, A.C.C; Stroe, L; 10.1016/j.nimb.2008.05.033

    2008-01-01

    Production of on-line mass separator neutron rich isotopes using fission induced by 1 GeV protons on high density uranium carbide has been investigate and results compared with the low density targets yields.

  7. Heavy Ion Reactions with Neutron-Rich Beams - Proceedings of the Riken International Workshop

    Science.gov (United States)

    Yamaji, S.; Ishihara, M.; Takigawa, N.

    1993-11-01

    The Table of Contents for the book is as follows: * Preface * Opening Address * Fusion I * Heavy Ion Fusion at Subbarrier Energies: Progress and Questions * Angular Momentum in Heavy Ion Subbarrier Interaction * Fusion II * High Precision Fusion Excitation Function Measurements: What Can We Learn from Them? * Transfer Reactions for 16O + 144,152Sm near the Coulomb Barrier * Fusion III * Recent Theoretical Developments in the Study of Subbarrier Fusion * Direct Reaction Approach to Heavy Ion Scattering and Fusion at Energies near Coulomb Barrier * Fusion IV * Roles of Multi-Step Transfer in Fusion Process Induced by Heavy Ion Reactions * Special Session * RIKEN Accelerator Research Facility (RARF) * Fission I * Bimodal Nature of Nuclear Fission * Systematics of Isotope Production Rates: Mass Excess Dependence of Fission Products * Semiclassical Methods for the Multi-Dimensional Quantum Decay * Dynamics of Di-Nucleus Systems: Molecular Resonances * Fission II * The Competition Between Fusion-Fission and Deeply Inelastic Reactions in the Medium Mass Systems * Unstable Nuclei I * Coulomb Dissociation and Momentum Distributions for 11Li → 9Li+n+n Breakup Reactions * Unstable Nuclei II * Elastic Scattering and Fragmentation of Halo Nuclei * Secondary Reactions of Neutron-Rich Nuclei at Intermediate Energies * Life Time of Soft Dipole Excitation * Unstable Nuclei III * Shell Structure of Exotic Unstable Nuclei * Properties of Unstable Nuclei Within the Relativistic Many-Body Theory * Fusion with Unstable Nuclei * Barrier Distributions for Heavy Ion Fusion * Heavy Ion Reactions with Neutron-Rich Beams * Heavy Ion Fusion with Neutron-Rich Beams * Superheavy Elements * Study of α Decays Following 40Ar Bombardment on 238U * Production of Superheavy Elements via Fusion: What is Limiting Us? * Panel Session * Comments * List of Participants

  8. Microscopic dynamics simulations of heavy-ion fusion reactions induced by neutron-rich nuclei

    CERN Document Server

    Wang, Ning; Zhang, Yingxun; Li, Zhuxia

    2014-01-01

    The heavy-ion fusion reactions induced by neutron-rich nuclei are investigated with the improved quantum molecular dynamics (ImQMD) model. With a subtle consideration of the neutron skin thickness of nuclei and the symmetry potential, the stability of nuclei and the fusion excitation functions of heavy-ion fusion reactions $^{16}$O+$^{76}$Ge, $^{16}$O+$^{154}$Sm, $^{40}$Ca+$^{96}$Zr and $^{132}$Sn+$^{40}$Ca are systematically studied. The fusion cross sections of these reactions at energies around the Coulomb barrier can be well reproduced by using the ImQMD model. The corresponding slope parameter of the symmetry energy adopted in the calculations is $L \\approx 78$ MeV and the surface energy coefficient is $g_{\\rm sur}=18\\pm 1.5$ MeVfm$^2$. In addition, it is found that the surface-symmetry term significantly influences the fusion cross sections of neutron-rich fusion systems. For sub-barrier fusion, the dynamical fluctuations in the densities of the reaction partners and the enhanced surface diffuseness at ...

  9. Measurement of the magnetic moment of the 2$^{+}$ state in neutron-rich radioactive $^{72,74}$Zn using the transient field technique in inverse kinematics

    CERN Multimedia

    Kruecken, R; Speidel, K; Voulot, D; Neyens, G; Gernhaeuser, R A; Fraile prieto, L M; Leske, J

    We propose to measure the sign and magnitude of the g-factors of the first 2$^{+}$ states in radioactive neutron-rich $^{72,74}$Zn applying the transient field (TF) technique in inverse kinematics. The result of this experiment will allow to probe the $\

  10. Characterization of uranium carbide target materials to produce neutron-rich radioactive beams

    Energy Technology Data Exchange (ETDEWEB)

    Tusseau-Nenez, Sandrine; Roussière, Brigitte; Barré-Boscher, Nicole [Institut de Physique Nucléaire (UMR8608) CNRS/IN2P3 – Université Paris Sud, 91406 Orsay Cedex (France); Gottberg, Alexander [CERN, CH-1211 Genève 23 (Switzerland); Corradetti, Stefano; Andrighetto, Alberto [INFN Laboratori Nazionali di Legnaro, Viale dell’Universit‘a 2, 35020 Legnaro (PD) (Italy); Cheikh Mhamed, Maher; Essabaa, Saïd [Institut de Physique Nucléaire (UMR8608) CNRS/IN2P3 – Université Paris Sud, 91406 Orsay Cedex (France); Franberg-Delahaye, Hanna; Grinyer, Joanna [Grand Accélérateur National d’Ions Lourds (GANIL), CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, 14076 Caen (France); Joanny, Loïc [Institut des Sciences Chimiques de Rennes (UMR 6226) CNRS – Université de Rennes 1, Campus de Beaulieu, 35042 RENNES Cedex (France); Lau, Christophe [Institut de Physique Nucléaire (UMR8608) CNRS/IN2P3 – Université Paris Sud, 91406 Orsay Cedex (France); Le Lannic, Joseph [Institut des Sciences Chimiques de Rennes (UMR 6226) CNRS – Université de Rennes 1, Campus de Beaulieu, 35042 RENNES Cedex (France); Raynaud, Marc; Saïd, Abdelhakim [Institut de Physique Nucléaire (UMR8608) CNRS/IN2P3 – Université Paris Sud, 91406 Orsay Cedex (France); Stora, Thierry [CERN, CH-1211 Genève 23 (Switzerland); and others

    2016-03-01

    In the framework of a R&D program aiming to develop uranium carbide (UC{sub x}) targets for radioactive nuclear beams, the Institut de Physique Nucléaire d’Orsay (IPNO) has developed an experimental setup to characterize the release of various fission fragments from UC{sub x} samples at high temperature. The results obtained in a previous study have demonstrated the feasibility of the method and started to correlate the structural properties of the samples and their behavior in terms of nuclear reaction product release. In the present study, seven UC{sub x} samples have been systematically characterized in order to better understand the correlation between their physicochemical characteristics and release properties. Two very different samples, the first one composed of dense UC and the second one of highly porous UC{sub x} made of multi-wall carbon nanotubes, were provided by the ActILab (ENSAR) collaboration. The others were synthesized at IPNO. The systems for irradiation and heating necessary for the release studies have been improved with respect to those used in previous studies. The results show that the open porosity is hardly the limiting factor for the fission product release. The homogeneity of the microstructure and the pore size distribution contributes significantly to the increase of the release. The use of carbon nanotubes in place of traditional micrometric graphite particles appears to be promising, even if the homogeneity of the microstructure can still be enhanced.

  11. GISELE: A resonant ionization laser ion source for the production of radioactive ions at GANIL

    Energy Technology Data Exchange (ETDEWEB)

    Lecesne, N.; Alves-Conde, R.; De Oliveira, F.; Dubois, M.; Flambard, J. L.; Franberg, H.; Jardin, P.; Leroy, R.; Pacquet, J. Y.; Pichard, A.; Saint-Laurent, M. G. [GANIL, BP 55027, 14076 Caen Cedex 5 (France); Coterreau, E.; Le Blanc, F.; Olivier, A. [IPN Orsay, BP 1-91406 Orsay (France); Gottwald, T.; Mattolat, C.; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Staudinger Weg 7, 55099 Mainz (Germany); Lassen, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3 (Canada); Rothe, S. [Department of Engineering, CERN, CH-1211 Geneva 23 (Switzerland)

    2010-02-15

    SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

  12. GISELE: A resonant ionization laser ion source for the production of radioactive ions at GANIL

    CERN Document Server

    Lecesne, N; Wendt, K; Mattolat, C; Rothe, S; Pichard, A; Pacquet, J Y; Dubois, M; Coterreau, E; Franberg, H; Leroy, R; Gottwald, T; Alves-Conde, R; Flambard, J L; De Oliveira, F; Le Blanc, F; Jardin, P; Olivier, A; Lassen, J

    2010-01-01

    SPIRAL2 is the new project under construction at GANIL to produce radioactive ion beams and in particular neutron rich ion beams. For the past 10 yr SPIRAL1 at GANIL has been delivering accelerated radioactive ion beams of gases. Both facilities now need to extend the range of radioactive ion beams produced to condensable elements. For that purpose, a resonant ionization laser ion source, funded by the French Research National Agency, is under development at GANIL, in collaboration with IPN Orsay, University of Mainz (Germany) and TRIUMF, Vancouver (Canada). A description of this project called GISELE (GANIL Ion Source using Electron Laser Excitation) is presented.

  13. Reaction dynamics and nuclear structure of moderately neutron-rich Ne isotopes by heavy ion reactions

    Directory of Open Access Journals (Sweden)

    Bottoni S.

    2014-03-01

    Full Text Available The heavy ion reaction 22Ne+208Pb at 128 MeV of bombarding energy has been studied using the PRISMA-CLARA experimental setup at Legnaro National Laboratories. Elastic, inelastic and one nucleon transfer cross sections have been measured. The experimental results are presented in parallel with the analysis on existing data for the unstable 24Ne nucleus, from the reaction 24Ne+208Pb at 182 MeV (measured at SPIRAL with the VAMOS-EXOGAM setup. The β2C charge deformation parameter for both 22Ne and 24Ne has been determined by a DWBA analysis of the experimental angular dis- tributions, showing a strong reduction for 24Ne.

  14. Extrapolation of neutron-rich isotope cross-sections from projectile fragmentation

    CERN Document Server

    Mocko, M; Sun, Z Y; Andronenko, L; Andronenko, M; Delaunay, F; Famiano, M; Friedman, W A; Henzl, V; Henzlova, D; Hui, H; Liu, X D; Lukyanov, S; Lynch, W G; Rogers, A M; Wallace, M S

    2007-01-01

    Using the measured fragmentation cross sections produced from the 48Ca and 64Ni beams at 140 MeV per nucleon on 9Be and 181Ta targets, we find that the cross sections of unmeasured neutron rich nuclei can be extrapolated using a systematic trend involving the average binding energy. The extrapolated cross-sections will be very useful in planning experiments with neutron rich isotopes produced from projectile fragmentation. The proposed method is general and could be applied to other fragmentation systems including those used in other radioactive ion beam facilities.

  15. Trapping radioactive ions

    CERN Document Server

    Kluge, Heinz-Jürgen

    2004-01-01

    Trapping devices for atomic and nuclear physics experiments with radioactive ions are becoming more and more important at accelerator facilities. While about ten years ago only one online Penning trap experiment existed, namely ISOLTRAP at ISOLDE/CERN, meanwhile almost every radioactive beam facility has installed or plans an ion trap setup. This article gives an overview on ion traps in the operation, construction or planing phase which will be used for fundamental studies with short-lived radioactive nuclides such as mass spectrometry, laser spectroscopy and nuclear decay spectroscopy. In addition, this article summarizes the use of gas cells and radiofrequency quadrupole (Paul) traps at different facilities as a versatile tool for ion beam manipulation like retardation, cooling, bunching, and cleaning.

  16. P.A.R.R.NE.: production of neutron rich radioactive atoms; P.A.R.R.NE.: production d`atomes radioactifs riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Bajeat, O.; Clapier, F.; Cottereau, E.; Ducourtieux, M.; Kotfila, L.; Lau, C.; Lefort, H.; Mueller, A.C.; Obert, J.; Pauwels, N.; Potier, J.C.; Proust, J.; Putaux, J.C.; Vogel, C. [Services Techniques, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France); Kandri Rody, S. [Dept. de Physique El-Jadida, El-Jadida (Morocco); Liang, C.F. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, 91 - Orsay (France); Mirea, M. [Horia Hulubei, National Institute for Physics and Nuclear Engineering, IFIN-HH, Bucharest (Romania)

    1999-11-01

    We have started the R and D program P.A.R.R.NE. Its aim is the investigation of the optimum conditions for the production of neutron-rich fission fragment beams extracted from thick targets irradiated by fast neutrons. (authors) 3 refs., 2 figs., 2 tabs.

  17. Probing shell structure and shape changes in neutron-rich sulfur isotopes through transient-field g factor measurements on fast radioactive beams of 38S and 40S

    CERN Document Server

    Davies, A D; Brown, B A; Campbell, C M; Cook, J M; Davidson, P M; Dinca, D C; Gade, A; Liddick, S N; Mantica, P F; Mertzimekis, T J; Müller, W F; Stuchbery, A E; Terry, J R; Tomlin, B E; Wilson, A N; Yoneda, K; Zwahlen, H

    2006-01-01

    The shell structure underlying shape changes in neutron-rich nuclei near N=28 has been investigated by a novel application of the transient field technique to measure the first-excited state g factors in 38S and 40S produced as fast radioactive beams. There is a fine balance between proton and neutron contributions to the magnetic moments in both nuclei. The g factor of deformed 40S does not resemble that of a conventional collective nucleus because spin contributions are more important than usual.

  18. Radioactive ion beam line in Lanzhou

    Institute of Scientific and Technical Information of China (English)

    詹文龙; 郭忠言; 刘冠华; 党建荣; 何锐荣; 周嗣信; 尹全民; 罗亦孝; 王义芳; 魏宝文; 孙志宇; 肖国青; 王金川; 江山红; 李加兴; 孟祥伟; 张万生; 秦礼军; 王全进

    1999-01-01

    Radioactive ion beam line in Lanzhou (RIBLL) has been constructed for the production of short-lived radioactive nuclei and studies of exotic nuclei far from the β-stability line. It has been put into operation recently at the National Laboratory of Heavy Ion Accelerator Lanzhou. RIBLL consists of two doubly achromatic parts with a solid acceptance ΔΩ≥6.5 msr, momentum acceptance Δp/p=±5% and maximum magnetic rigidity Bρmax=4.2 Tm. The second part of RIBLL serving as a spectrometer gives an element resolution Z/ΔZ>150 and mass resolution A/ΔA>300. The polarized secondary beams can be obtained by using a swinger dipole magnet to change the incident direction of primary projectile from 0°to 5°. The shortest lift time for secondary beams on RIBLL is less than 1μs. First experiments were performed with neutron rich nuclei for understanding the properties of halo nuclei and exotic nuclear reactions.

  19. Neutron-Rich Silver Isotopes Produced by a Chemically Selective Laser Ion-Source: Test of the R-Process " Waiting-Point " Concept

    CERN Multimedia

    2002-01-01

    The r-process is an important nucleosynthesis mechanism for several reasons: \\begin{enumerate} \\item It is crucial to an understanding of about half of the A>60 elemental composition of the Galaxy; \\item It is the mechanism that forms the long-lived Th-U-Pu nuclear chronometers which are used for cosmochronolgy; \\item It provides an important probe for the temperature (T$ _{9} $)-neutron density ($n_{n}$) conditions in explosive events; and last but not least \\item It may serve to provide useful clues to and constraints upon the nuclear properties of very neutron-rich heavy nuclei. \\end{enumerate} \\\\ \\\\With regard to nuclear-physics data, of particular interest are the T$ _{1/2} $ and P$_{n-} $ values of certain$\\,$ "waiting-point"$\\,$ isotopes in the regions of the A $ \\approx $ 80 and 130. r-abundance peaks. Previous studies of $^{130}_{\\phantom{1}48}$Cd$_{82}$ and $^{79}_{29}$Cu$_{50}$. $\\beta$-decay properties at ISOLDE using a hot plasma ion source were strongly complicated by isobar and molecular-ion c...

  20. Ion trap system for radioactive ions at JYFL

    Energy Technology Data Exchange (ETDEWEB)

    Kolhinen, V.S.; Jokinen, A.; Rinta-Antila, S.; Szerypo, J. [University of Jyvaeskylae, Department of Physics (Finland); Aeystoe, J. [CERN, Geneva (Switzerland)

    2001-07-01

    The goal of the ion trap project in Jyvaeskylae is to improve the quality of radioactive beams at IGISOL (Ion Guide Isotope Separator On-Line), in terms of transverse emittance, energy spread and purity. This improvement is achieved with an aid of an RFQ cooler/buncher and a mass-selective cylindrical Penning trap (mass resolving power up to 10{sup 5}). Their final purpose is to produce cooled isobarically pure beams of exotic radioactivities mainly of exotic neutron-rich isotopes from fission (including refractory elements). In the Penning trap ions are confined in three dimensions in a superposition of static quadrupole electric and homogeneous magnetic fields. The magnetic field confines the ions in two dimensions in a plane perpendicular to the field direction. A confinement in the third, magnetic field direction (parallel to the trap axis) is done by a quadrupole electric field. The Penning trap system in Jyvaeskylae (JYFLTRAP) will contain two cylindrical Penning traps placed inside the same superconducting magnet (B=7 T). The first, purification trap, will accept cooled (continuous or bunched) beams from the RFQ cooler/buncher and perform the isobaric purification. The latter is - done using a combination of a buffer gas cooling and an azimuthal quadrupole RF-field providing mass- dependent centering of ions. This, in turn, allows mass-selective ejection of ions in short pulses. Clean monoisotopic bunched beams will be delivered for the nuclear spectroscopy studies, collinear laser spectroscopy experiments and precise nuclear mass measurements (10{sup -7} precision). The latter will be performed in the second, precision Penning trap (author)

  1. The CARDS array for neutron-rich decay spectroscopy at HRIBF

    CERN Document Server

    Batchelder, J C; Bingham, C R; Carter, H K; Cole, J D; Fong, D; Garrett, P E; Grzywacz, R; Hamilton, J H; Hartley, D J; Hwang, J K; Krolas, W; Kulp, D C; Larochelle, Y; Piechaczek, A; Ramayya, A V; Rykaczewski, K; Spejewski, E H; Stracener, D W; Tantawy, M N; Winger, J A; Wood, J; Zganjar, E F

    2003-01-01

    An array for decay studies of neutron-rich nuclei has been commissioned for use at the UNISOR separator at Holifield Radioactive Ion Beam Facility. This array consists of three segmented clover Ge detectors, plastic scintillators, and a high-resolution (approx 1 keV) Si conversion electron spectrometer. These detectors are mounted on a support that surrounds a moving tape collector. This system has been named clover array for radioactive decay studies. The detectors have been outfitted with digital flash ADCs (XIA DGFs) that fit the preamp signals, with built-in pileup rejection.

  2. Direct reaction experimental studies with beams of radioactive tin ions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K. L., E-mail: kgrzywac@utk.edu; Ayres, A.; Bey, A.; Burcher, S.; Cartegni, L.; Cerizza, G. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Ahn, S. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Allmond, J. M.; Beene, J. R.; Galindo-Uribarri, A.; Liang, J. F.; Nesaraja, C. D.; Pain, S. D.; Radford, D. C.; Schmitt, K. T.; Smith, M. S.; Stracener, D. W.; Varner, R. L. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Bardayan, D. W. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Baugher, T. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903 (United States); and others

    2015-10-15

    The tin chain of isotopes provides a unique region in which to investigate the evolution of single-particle structure, spreading from N = 50 at {sup 100}Sn, through 10 stable isotopes and the N = 82 shell closure at {sup 132}Sn out into the r-process path. Direct reactions performed on radioactive ion beams are sensitive spectroscopic tools for studying exotic nuclei. Here we present one experiment knocking out neutrons from tin isotopes that are already neutron deficient and two reactions that add a neutron to neutron-rich {sup 130}Sn. Both techniques rely on selective particle identification and the measurement of γ rays in coincidence with charged ions. We present the goals of the two experiments and the particle identification for the channels of interest. The final results will be presented in future publications.

  3. Direct Reaction Experimental Studies with Beams of Radioactive Tin Ions

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K. L. [University of Tennessee, Knoxville (UTK); Ahn, S.H. [University of Tennessee, Knoxville (UTK); Allmond, James M [ORNL; Ayres, A. [University of Tennessee, Knoxville (UTK); Bardayan, Daniel W [ORNL; Baugher, T. [Michigan State University, East Lansing; Bazin, D. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL); Beene, James R [ORNL; Berryman, J. S. [Michigan State University, East Lansing; Bey, A. [University of Tennessee, Knoxville (UTK); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Cartegni, L. [University of Tennessee, Knoxville (UTK); Chae, K. Y. [University of Tennessee, Knoxville (UTK)/Sungkyunkwan University, Korea; Cizewski, J. A. [Rutgers University; Gade, A. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL); Galindo-Uribarri, Alfredo {nmn} [ORNL; Garcia-Ruiz, R.F. [Instituut voor Kernen Stralingsfysica, KU Leuven, B-3001, Leuven, Belgium; Grzywacz, Robert Kazimierz [ORNL; Howard, Meredith E [ORNL; Kozub, R. L. [Tennessee Technological University (TTU); Liang, J Felix [ORNL; Manning, Brett M [ORNL; Matos, M. [Louisiana State University; McDaniel, S. [Michigan State University, East Lansing; Miller, D. [University of Tennessee, Knoxville (UTK); Nesaraja, Caroline D [ORNL; O' Malley, Patrick [Rutgers University; Padgett, S [University of Tennessee, Knoxville (UTK); Padilla-Rodal, Elizabeth [Universidad Nacional Autonoma de Mexico (UNAM); Pain, Steven D [ORNL; Pittman, S. T. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Radford, David C [ORNL; Ratkiewicz, Andrew J [ORNL; Schmitt, Kyle [ORNL; Smith, Michael Scott [ORNL; Stracener, Daniel W [ORNL; Stroberg, S. [Michigan State University, East Lansing; Tostevin, Jeffrey A [ORNL; Varner Jr, Robert L [ORNL; Weisshaar, D. [Michigan State University, East Lansing; Wimmer, K. [Michigan State University, National Superconducting Cyclotron Laboratory (NSCL)/Central Michigan University; Winkler, R. [Michigan State University, East Lansing

    2015-01-01

    The tin chain of isotopes provides a unique region in which to investigate the evolution of single-particle structure, spreading from N = 50 at Sn-100, through 10 stable isotopes and the N = 82 shell closure at Sn-132 out into the r-process path. Direct reactions performed on radioactive ion beams are sensitive spectroscopic tools for studying exotic nuclei. Here we present one experiment knocking out neutrons from tin isotopes that are already neutron deficient and two reactions that add a neutron to neutron-rich Sn-130. Both techniques rely on selective particle identification and the measurement of gamma rays in coincidence with charged ions. We present the goals of the two experiments and the particle identification for the channels of interest. The final results will be presented in future publications.

  4. Fifth International Conference on Fission and Properties of Neutron-Rich Nuclei

    CERN Document Server

    Ramayya, A V; ICFN5

    2014-01-01

    These proceedings are the fifth in the series of International Conferences covering fission and properties of neutron-rich nuclei, which are at the forefront of nuclear research. The time interval of 5 years between each conference allows for significant new results to be achieved. Recently, world leaders in theory and experiments in research and the development of new facilities for research presented their latest results in areas such as synthesis of superheavy elements, new facilities for and recent results with radioactive ion beams, structure of neutron-rich nuclei, nuclear fission process, fission yields and nuclear astrophysics. This book is a major source of the latest research in these areas and plans for the future. The conference brought together a unique group of over 100 speakers including leaders from the major nuclear laboratories in Canada, China, France, Finland, Germany, Italy, Japan, Russia, Switerzland and the US along with leading research scientists from around the world.

  5. $\\beta$-decay study of very neutron-rich Cd isotopes with a chemically selective laser ion source

    CERN Multimedia

    2002-01-01

    Following our test measurements of N=82-84 Cd isotopes with a specifically developed laser ion source (CERN/ISC 97-16, ISC/I 22), we now propose detailed spectroscopic studies of the decay of $^{130}$Cd to $\\,^{132}\\!$Cd, and at least the determination of some gross properties of the new N=85-86 nuclides $^{133}\\!$Cd and $\\,^{134}\\!$Cd. The main nuclear-structure objective of this experiment is the identification of the energies of the single-hole (SH) proton states in $^{131}$In. Nearly all of the other single-nucleon shell-model basis energies around doubly magic $^{132}$Sn are known by now, except those $\\pi$SH in Z=49 $\\,^{131}$In. Theoretical agreement on these values has not been achieved so far. Of particular interest is the depth of the $\\pi$f$_{5/3}$ hole and the p$_{3/2}$ - p$_{1/2}$ spin-orbit splitting. A second important goal is the determination of the position of the lowest-energy 1$^+\\,$ level in $^{130}$In predominantly populated in the Gamow-Teller (GT) decay of N=82 $^{130}\\!$Cd. Apart from...

  6. Fission and Properties of Neutron-Rich Nuclei

    Science.gov (United States)

    Hamilton, Joseph H.; Ramayya, A. V.; Carter, H. K.

    2008-08-01

    Opening session. Nuclear processes in stellar explosions / M. Wiescher. In-beam [symbol]-ray spectroscopy of neutron-rich nuclei at NSCL / A. Gade -- Nuclear structure I. Shell-model structure of neutron-rich nuclei beyond [symbol]Sn / A. Covello ... [et al.]. Shell structure and evolution of collectivity in nuclei above the [symbol]Sn core / S. Sarkar and M. S. Sarkar. Heavy-ion fusion using density-constrained TDHF / A. S. Umar and V. E. Oberacker. Towards an extended microscopic theory for upper-fp shell nuclei / K. P. Drumev. Properties of the Zr and Pb isotopes near the drip-line / V. N. Tarasov ... [et al.]. Identification of high spin states in [symbol] Cs nuclei and shell model calculations / K. Li ... [et al.]. Recent measurements of spherical and deformed isomers using the Lohengrin fission-fragment spectrometer / G. S. Simpson ... [et al.] -- Nuclear structure II. Nuclear structure investigation with rare isotope spectroscopic investigations at GSI / P. Boutachkov. Exploring the evolution of the shell structures by means of deep inelastic reactions / G. de Anaelis. Probing shell closures in neutron-rich nuclei / R. Krücken for the S277 and REX-ISOLDEMINIBALL collaborations. Structure of Fe isotopes at the limits of the pf-shell / N. Hoteling ... [et al.]. Spectroscopy of K isomers in shell-stabilized trans-fermium nuclei / S. K. Tandel ... [et al.] -- Radioactive ion beam facilities. SPIRAL2 at GANIL: a world leading ISOL facility for the next decade / S. Gales. New physics at the International Facility for Antiproton and Ion Research (FAIR) next to GSI / I. Augustin ... [et al.]. Radioactive beams from a high powered ISOL system / A. C. Shotter. RlKEN RT beam factory / T. Motobayashi. NSCL - ongoing activities and future perspectives / C. K. Gelbke. Rare isotope beams at Argonne / W. F. Henning. HRIBF: scientific highlights and future prospects / J. R. Beene. Radioactive ion beam research done in Dubna / G. M. Ter-Akopian ... [et al.] -- Fission I

  7. Charge Breeding of Radioactive Ions

    CERN Document Server

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  8. Precision mass measurements for studies of nucleosynthesis via the rapid neutron-capture process. Penning-trap mass measurements of neutron-rich cadmium and caesium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Atanasov, Dinko

    2016-07-06

    Although the theory for the rapid neutron-capture process (r-process) was developed more than 55 years ago, the astrophysical site is still under a debate. Theoretical studies predict that the r-process path proceeds through very neutron-rich nuclei with very asymmetric proton-to-neutron ratios. Knowledge about the properties of neutron-rich isotopes found in similar regions of the nuclear chart and furthermore suitable for r-process studies is still little or even not existing. The basic nuclear properties such as binding energies, half-lives, neutron-induced or neutron-capture reaction cross-sections, play an important role in theoretical simulations and can vary or even drastically alternate results of these studies. Therefore, a considerable effort was put forward to access neutron-rich isotopes at radioactive ion-beam facilities like ISOLDE at CERN. The goal of this PhD thesis is to describe the experimental work done for the precision mass measurements of neutron-rich cadmium ({sup 129-131}Cd) and caesium ({sup 132,146-148}Cs) isotopes. Measurements were done at the on-line radioactive ion-beam facility ISOLDE by using the four-trap mass spectrometer ISOLTRAP. The cadmium isotopes are key nuclides for the synthesis of stable isotopes around the mass peak A = 130 in the Solar System abundance.

  9. Radioactive Ion Beams and Radiopharmaceuticals

    Science.gov (United States)

    Laxdal, R. E.; Morton, A. C.; Schaffer, P.

    2014-02-01

    Experiments performed at radioactive ion beam facilities shed new light on nuclear physics and nuclear structure, as well as nuclear astrophysics, materials science and medical science. The many existing facilities, as well as the new generation of facilities being built and those proposed for the future, are a testament to the high interest in this rapidly expanding field. The opportunities inherent in radioactive beam facilities have enabled the search for radioisotopes suitable for medical diagnosis or therapy. In this article, an overview of the production techniques and the current status of RIB facilities and proposals will be presented. In addition, accelerator-generated radiopharmaceuticals will be reviewed.

  10. Fusion using radioactive ion beams

    Indian Academy of Sciences (India)

    A M Vinodkumar

    2010-07-01

    The capture-fission cross-section is measured for the collision of the massive nucleus 132Sn with 96Zr at near-barrier energies and compared with the collision of 124Sn with 96Zr. This study gives insight into fusion enhancement and hindrance in systems involving neutron-rich nuclei. The dinuclear system model (DNS) calculations describe the excitation function reasonably well and if we use the barrier heights predicted by this model we can conclude that fusion hindrance (represented by extra push energy) is greater for the more neutron-rich systems. The fusion excitation function for 9Li+70Zn and 9Li+208Pb systems are measured for near-barrier energies using ISAC1 and ISAC2 Facilities at TRIUMF. The -emitting evaporation residues (211−214At) are stopped in the 208Pb target and their decay is measured. The measured excitation function shows evidence for large enhancements in the sub-barrier energies, which is not accounted by current theoretical models. Suppression of the above-barrier cross-section with respect to these theoretical models are also seen.

  11. Precision mass measurements for studies of nucleosynthesis via the rapid neutron-capture process Penning-trap mass measurements of neutron-rich cadmium and caesium isotopes

    CERN Document Server

    AUTHOR|(CDS)2085660; Litvinov, Yuri A.; Kreim, Susanne

    Although the theory for the rapid neutron-capture process (r-process) was developed more than 55 years ago, the astrophysical site is still under a debate. Theoretical studies predict that the r-process path proceeds through very neutron-rich nuclei with very asymmetric proton- to-neutron ratios. Knowledge about the properties of neutron-rich isotopes found in similar regions of the nuclear chart and furthermore suitable for r-process studies is still little or even not existing. The basic nuclear properties such as binding energies, half-lives, neutron-induced or neutron-capture reaction cross-sections, play an important role in theoretical simulations and can vary or even drastically alternate results of these studies. Therefore, a considerable effort was put forward to access neutron-rich isotopes at radioactive ion-beam facilities like ISOLDE at CERN. The goal of this PhD thesis is to describe the experimental work done for the precision mass measurements of neutron-rich cadmium (129−131 Cd) and caesium...

  12. Shell structure in neutron rich nuclei by means of binary reactions

    Energy Technology Data Exchange (ETDEWEB)

    Angelis, G. de [INFN, Laboratori Nazionali di Legnaro (Italy)

    2014-08-14

    Nuclear structure studies far from stability rely mainly on the availability of radioactive nuclear beams but can complementary be addressed by means of high intensity beams of stable ions. In such contest, deep-inelastic and multinucleon transfer reactions are a powerful tool to populate yrast and non yrast states in neutron-rich nuclei. Particularly successful is here the combination of large acceptance spectrometers with highly segmented gamma-detector arrays. Such devices can provide the necessary channel selectivity to identify very rare signals. The AGATA gamma-ray detector array coupled to the PRISMA spectrometer at the Legnaro National Laboratories (LNL) in Italy is one example. Large data sets have been collected at LNL for nuclei close to the N=20, 28, 40, 50 and 82 shell closures.

  13. Time-of-Flight Mass Measurements of Neutron Rich Nuclides

    Science.gov (United States)

    Estrade, A.; Matos, M.; Amthor, A. M.; Becerril, A.; Elliot, T.; Lorusso, G.; Rogers, A.; Schatz, H.; Bazin, D.; Gade, A.; Portillo, M.; Stolz, A.; Galaviz, D.; Pereira, J.; Shapira, D.; Smith, E.; Wallace, M.

    2008-10-01

    Nuclear masses of neutron rich isotopes in the region of Z ˜ 20-30 have been measured using the time-of-flight technique at the National Superconducting Cyclotron Laboratory (NSCL). The masses of 5 isotopes have been measured for the first time, and the precision of several other masses has been improved. The time-of-flight technique has shown the potential to access nuclear masses very far from stability when applied at radioactive beam facilities like the NSCL. Such measurements are important for understanding nuclear structure far from the valley of β-stability, and provide valuable information for astrophysical model calculations of processes involving very unstable nuclides.

  14. Development of target ion source systems for radioactive beams at GANIL

    Energy Technology Data Exchange (ETDEWEB)

    Bajeat, O., E-mail: bajeat@ganil.fr [GANIL, BP 55027, 14076 CAEN Cedex 05 (France); Delahaye, P. [GANIL, BP 55027, 14076 CAEN Cedex 05 (France); Couratin, C. [GANIL, BP 55027, 14076 CAEN Cedex 05 (France); LPC Caen, 6 bd Maréchal Juin, 14050 CAEN Cedex (France); Dubois, M.; Franberg-Delahaye, H.; Henares, J.L.; Huguet, Y.; Jardin, P.; Lecesne, N.; Lecomte, P.; Leroy, R.; Maunoury, L.; Osmond, B.; Sjodin, M. [GANIL, BP 55027, 14076 CAEN Cedex 05 (France)

    2013-12-15

    Highlights: • For Spiral 1, a febiad ion source has been connected to a graphite target. • For Spiral 2, an oven made with a carbon resistor is under development. • We made some measurement of effusion in the Spiral 2 target. • A laser ion source is under construction. -- Abstract: The GANIL facility (Caen, France) is dedicated to the acceleration of heavy ion beams including radioactive beams produced by the Isotope Separation On-Line (ISOL) method at the SPIRAL1 facility. To extend the range of radioactive ion beams available at GANIL, using the ISOL method two projects are underway: SPIRAL1 upgrade and the construction of SPIRAL2. For SPIRAL1, a new target ion source system (TISS) using the VADIS FEBIAD ion source coupled to the SPIRAL1 carbon target will be tested on-line by the end of 2013 and installed in the cave of SPIRAL1 for operation in 2015. The SPIRAL2 project is under construction and is being design for using different production methods as fission, fusion or spallation reactions to cover a large area of the chart of nuclei. It will produce among others neutron rich beams obtained by the fission of uranium induced by fast neutrons. The production target made from uranium carbide and heated at 2000 °C will be associated with several types of ion sources. Developments currently in progress at GANIL for each of these projects are presented.

  15. Production of negatively charged radioactive ion beams

    Science.gov (United States)

    Liu, Y.; Stracener, D. W.; Stora, T.

    2017-08-01

    Beams of short-lived radioactive nuclei are needed for frontier experimental research in nuclear structure, reactions, and astrophysics. Negatively charged radioactive ion beams have unique advantages and allow for the use of a tandem accelerator for post-acceleration, which can provide the highest beam quality and continuously variable energies. Negative ion beams can be obtained with high intensity and some unique beam purification techniques based on differences in electronegativity and chemical reactivity can be used to provide beams with high purity. This article describes the production of negative radioactive ion beams at the former holifield radioactive ion beam facility at Oak Ridge National Laboratory and at the CERN ISOLDE facility with emphasis on the development of the negative ion sources employed at these two facilities. ).

  16. Fission and Properties of Neutron-Rich Nuclei - Proceedings of the Second International Conference

    Science.gov (United States)

    Hamilton, J. H.; Phillips, W. R.; Carter, H. K.

    The Table of Contents for the book is as follows: * Preface * Structure of Elementary Matter: Cold Valleys and Their Importance in Fission, Fusion and for Superheavy Nuclei * Tunnelling Phenomena in Nuclear Physics * Heavy Nuclei Studies Using Transfer Reactions * Isomeric Properties of Nuclei Near 78Ni * Investigation of Light Actinide Nuclei at Yale and Beyond * U-Projectile Fission at Relativistic Energies * Cluster Description of Cold Fission Modes in 252Cf * Neutron-pair Transfer Theory for Pear-shaped Ba Fission Fragments * New RMFA Parameters of Normal and Exotic Nuclei * Study of Fission Fragments from 12C+238U Reactions: Prompt and Delayed Spectroscopy * γ-Ray Angular Correlations in 252Cf and 248Cm Fission Fragments * Fragment Angular Momentum and Descent Dynamics in 252Cf Spontaneous Fission * The Experimental Investigation of Neutron-Rich Nuclei * High-Spin Structure of Some Odd-Z Nuclei with A ≈ 100 From Heavy-Ion Induced Fission * Coexistence of Symmetric and Asymmetric Nuclear Shapes and 10Be Ternary Fission * Octupole Effects in the Lanthanides * High Spin Structure of the 113-1l6Cd Isotopes Produced by Heavy-Ion Induced Fission Reaction * Temperature-Dependent Fission Barriers and Mass Distributions for 239U * Strength Distributions for Gamow Teller Transitions in Very Weakly Bound Systems * High Spin Fragmentation Spectroscopy * Search for a Four-Neutron Transfer From 8He to 4He * Microsecond Isomers in Fission Fragments in the Vicinity of the Doubly Magic 132Sn * Recent On-Line NMR/on Nuclear Magnetic Dipole Moments Near 132Sn: Meson Exchange Current Effects at the Shell Closure and Shell Model Treatment of Variation with Proton and Neutron Number * High-spin K-Isomers Beyond the Fusion Limit * High Energy Neutron Induced Fission: Charge Yield Distributions and Search and Spectroscopy of New Isomers * Hartree-Fock Mean-Field Models Using Separable Interactions * Variation of Fission Characteristics Over the Nuclear Chart * Investigation of

  17. Radioactive Ion Beam Development at the Holifield Radioactive Ion Beam Facility

    CERN Document Server

    Stracener, Dan; Beene, James R; Bilheux, Hassina Z; Bilheux, Jean-Christophe; Blackmon, Jeff C; Carter, Ken; Dowling, Darryl; Juras, Raymond; Kawai, Yoko; Kronenberg, Andreas; Liu, Yuan; Meigs, Martha; Müller, Paul; Spejewski, Eugene H; Tatum, A

    2005-01-01

    Radioactive beams are produced at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory using the Isotope Separator On-Line (ISOL) technique. Radioactive nuclei are produced in a thick target via irradiation with energetic light ions (protons, deuterons, helium isotopes) and then post-accelerated to a few MeV/nucleon for use in nuclear physics experiments. An overview of radioactive beam development at the HRIBF will be presented, including ion source development, improvements in the ISOL production targets, and a description of techniques to improve the quality (intensity and purity) of the beams. Facilities for radioactive ion beam development include two ion source test facilities, a target/ion source preparation and quality assurance facility, and an in-beam test facility where low intensity production beams are used. A new test facility, the High Power Target Laboratory, will be available later this year. At this facility, high intensity production beams will be available t...

  18. Radioactive ions and atoms in superfluid helium

    NARCIS (Netherlands)

    Dendooven, P.G.; Purushothaman, S.; Gloos, K.; Aysto, J.; Takahashi, N.; Huang, W.; Harissopulos, S; Demetriou, P; Julin, R

    2006-01-01

    We are investigating the use of superfluid helium as a medium to handle and manipulate radioactive ions and atoms. Preliminary results on the extraction of positive ions from superfluid helium at temperatures close to 1 K are described. Increasing the electric field up to 1.2 kV/cm did not improve t

  19. Coulomb excitation of neutron-rich beams at REX-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Scheit, H.; Niedermaier, O.; Bildstein, V.; Boie, H.; Fitting, J.; Hahn, R. von; Koeck, F.; Lauer, M.; Pal, U.K.; Podlech, H.; Repnow, R.; Schwalm, D. [Max-Planck-Insitut fuer Kernphysik, Heidelberg (Germany); Alvarez, C.; Ames, F.; Bollen, G.; Emhofer, S.; Habs, D.; Kester, O.; Lutter, R.; Rudolph, K.; Pasini, M.; Thirolf, P.G.; Wolf, B.H. [Ludwig-Maximilians-Univ., Muenchen (Germany); Eberth, J.; Gersch, G.; Hess, H.; Reiter, P.; Thelen, O.; Warr, N.; Weisshaar, D. [Univ. Koeln, Inst. fuer Kernphysik, Koeln (Germany); Aksouh, F.; Van den Bergh, P.; Van Duppen, P.; Huyse, M.; Ivanov, O.; Mayet, P.; Van de Walle, J. [Univ. of Leuven, Inst. voor Kern- en Stralingsfysica, Leuven (Belgium); Aeystoe, J.; Butler, P.A.; Cederkaell, J.; Delahaye, P.; Fynbo, H.O.U.; Fraile, L.M.; Forstner, O.; Koester, U.; Oinonen, M.; Sieber, T.; Wenander, F. [CERN, Geneva (Switzerland); Franchoo, S. [CERN, Geneva (Switzerland)]|[Johannes Gutenberg-Univ., Mainz (Germany); Nilsson, T. [CERN, Geneva (Switzerland)]|[Inst. fuer Kernphysik, Technische Univ. Darmstadt (Germany); Pantea, M.; Richter, A.; Schrieder, G.; Simon, H. [Technische Univ. Darmstadt, Inst. fuer Kernphysik, Darmstadt (Germany); Behrens, T.; Gernhaeuser, R.; Kroell, T.; Kruecken, R.; Muench, M. [Technische Univ. Muenchen, Garching (Germany); Davinson, T. [Univ. of Edinburgh, Edinburgh (United Kingdom); Gerl, J. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany); Huber, G.; Schmidt, P. [Johannes Gutenberg-Univ., Mainz (Germany); Hurst, A. [Univ. of Liverpool, Oliver Lodge Lab. (United Kingdom); Iwanicki, J. [Warsaw Univ., Heavy Ion Lab., Warsaw (Poland); Jonson, B. [Chalmers Tekniska Hoegskola, Goeteborg (Sweden); Lieb, P. [Georg-August-Univ., Goettingen (Germany); Liljeby, L. [Manne Siegbahn Lab., Stockholm (Sweden); Schempp, A. [Johann Wolfgang Goethe-Univ., Frankfurt (Germany); Scherillo, A. [Inst. fuer Kernphysik, Univ. Koeln (Germany)]|[Inst. Laue-Langevin, Grenoble (France)

    2005-09-01

    After the successful commissioning of the radioactive beam experiment at ISOLDE (REX-ISOLDE) -an accelerator for exotic nuclei produced by ISOLDE- in 2002 and the promotion to a CERN user facility in 2003, first physics experiments using these beams were performed. Initial experiments focused on the region of deformation in the vicinity of the neutron-rich Na and Mg isotopes. Preliminary results on the neutron-rich Na and Mg isotopes show the high potential and physics opportunities offered by the exotic isotope accelerator REX in conjunction with the modern Germanium {gamma} spectrometer MINIBALL. (orig.)

  20. Unexpectedly large charge radii of neutron-rich calcium isotopes

    Science.gov (United States)

    Garcia Ruiz, R. F.; Bissell, M. L.; Blaum, K.; Ekström, A.; Frömmgen, N.; Hagen, G.; Hammen, M.; Hebeler, K.; Holt, J. D.; Jansen, G. R.; Kowalska, M.; Kreim, K.; Nazarewicz, W.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Papenbrock, T.; Papuga, J.; Schwenk, A.; Simonis, J.; Wendt, K. A.; Yordanov, D. T.

    2016-06-01

    Despite being a complex many-body system, the atomic nucleus exhibits simple structures for certain `magic’ numbers of protons and neutrons. The calcium chain in particular is both unique and puzzling: evidence of doubly magic features are known in 40,48Ca, and recently suggested in two radioactive isotopes, 52,54Ca. Although many properties of experimentally known calcium isotopes have been successfully described by nuclear theory, it is still a challenge to predict the evolution of their charge radii. Here we present the first measurements of the charge radii of 49,51,52Ca, obtained from laser spectroscopy experiments at ISOLDE, CERN. The experimental results are complemented by state-of-the-art theoretical calculations. The large and unexpected increase of the size of the neutron-rich calcium isotopes beyond N = 28 challenges the doubly magic nature of 52Ca and opens new intriguing questions on the evolution of nuclear sizes away from stability, which are of importance for our understanding of neutron-rich atomic nuclei.

  1. A Multicusp Ion Source for Radioactive Ion Beams

    Science.gov (United States)

    Wutte, D.; Freedman, S.; Gough, R.; Lee, Y.; Leitner, M.; Leung, K. N.; Lyneis, C.; Picard, D. S.; Sun, L.; Williams, M. D.; Xie, Z. Q.

    1997-05-01

    In order to produce a radioactive ion beam of (14)O+, a 10-cm-diameter, 13.56 MHz radio frequency (rf) driven multicusp ion source is now being developed at Lawrence Berkeley National Laboratory. In this paper we describe the specific ion source design and the basic ion source characteristics using Ar, Xe and a 90types of measurements have been performed: extractable ion current, ion species distributions, gas efficiency, axial energy spread and ion beam emittance measurements. The source can generate ion current densities of approximately 60 mA/cm2 . In addition the design of the ion beam extraction/transport system for the actual experimental setup for the radioactive beam line will be presented.

  2. Laser Spectroscopy Studies in the Neutron-Rich Sn Region

    CERN Multimedia

    Obert, J

    2002-01-01

    We propose to use the powerful laser spectroscopy method to determine the magnetic moment $\\mu$ and the variation of the mean square charge radius ($\\delta\\,\\langle$r$_{c}^{2}\\,\\rangle$) for ground and long-lived isomeric states of the Sn isotopes from A=125 to the doubly-magic $^{132}$Sn isotope and beyond. For these neutron-rich Sn nuclei, numerous $\\delta\\,\\langle$r$^{2}_{c}\\,\\rangle$ curves have already been calculated and the predictions depend upon the effective interactions used. Therefore, a study of the effect of the shell closure N=82 on the $\\delta\\,\\langle$r$^{2}_{c}\\,\\rangle$ values in the Z=50 magic nuclei is of great interest, especially because $^{132}$Sn is located far from the stability valley. It will help to improve the parameters of the effective interactions and make them more suitable to predict the properties of exotic nuclei. \\\\ \\\\The neutron-rich Sn isotopes produced with an uranium carbide target, are ionized using either a hot plasma ion source or the resonant ionization laser ion ...

  3. Radioactive ion beam development in Berkeley

    CERN Document Server

    Wutte, D C; Leitner, M A; Xie, Z Q

    1999-01-01

    Two radioactive ion beam projects are under development at the 88" Cyclotron, BEARS (Berkeley Experiment with accelerated radioactive species) and the 14O experiment. The projects are initially focused on the production of 11C and 14O, but it is planned to expand the program to 17F, 18F, 13N and 76Kr. For the BEARS project, the radioactivity is produced in form of either CO2 or N2O in a small medical 10 MeV proton cyclotron. The activity is then transported through a 300 m long He-jet line to the 88" cyclotron building, injected into the AECR-U ion source and accelerated through the 88" cyclotron to energies between 1 to 30 MeV/ nucleon. The 14O experiment is a new experiment at the 88" cyclotron to measure the energy-shape of the beta decay spectrum. For this purpose, a target transfer line and a radioactive ion beam test stand has been constructed. The radioactivity is produced in form of CO in a hot carbon target with a 20 MeV 3He from the 88" Cyclotron. The activity diffuses through an 8m long stainless s...

  4. Radioactive ion beams in nuclear astrophysics

    Science.gov (United States)

    Gialanella, L.

    2016-09-01

    Unstable nuclei play a crucial role in the Universe. In this lecture, after a short introduction to the field of Nuclear Astrophysics, few selected cases in stellar evolution and nucleosynthesis are discussed to illustrate the importance and peculiarities of processes involving unstable species. Finally, some experimental techniques useful for measurements using radioactive ion beams and the perspectives in this field are presented.

  5. Nuclear shell effects in neutron-rich nuclei around N=20 and N=32,34

    CERN Document Server

    Seidlitz, M

    Nuclear shell effects in neutron-rich nuclei around N=20 and N=32,34 were studied by means of reduced transition probabilities, i.e. B(E2) and B(M1) values. To this end a series of Coulomb-excitation experiments, employing radioactive 31Mg and 29,30Na beams, as well as a precise lifetime experiment of excited states in 56Cr were performed. The collective properties of excited states of 31Mg were the subject of a Coulomb-excitation experiment at REX-ISOLDE, CERN, employing a radioactive 31Mg beam at a beam energy of 3.0 MeV/u. The beam intensity amounted to 3000 ions/s on average. The highly efficient MINIBALL setup was employed, consisting of eight HPGe cluster detectors for gamma-ray detection and a segmented Si-detector for coincident particle detection. The level scheme of 31Mg was extended. Spin and parity assignment of the observed 945 keV state yielded 5/2+ and its de-excitation is dominated by a strong collective M1 transition. Comparison of the transition probabilities of 30,31,32Mg establishes that f...

  6. Radioactive Ion Beam Production by Fast-Neutron-Induced Fission in Actinide Targets at EURISOL

    CERN Document Server

    Herrera-Martínez, Adonai

    The European Isotope Separation On-Line Radioactive Ion Beam Facility (EURISOL) is set to be the 'next-generation' European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, the production of high-intensity RIBs of specific neutron-rich isotopes is obtained by inducing fission in large-mass actinide targets. In our contribution, the use of uranium targets is shown to be advantageous to other materials, such as thorium. Therefore, in order to produce fissions in U-238 and reduce the plutonium inventory, a fast neutron energy spectrum is necessary. The large beam power required to achieve these RIB levels requires the use of a liquid proton-to-neutron converter. This article details the design parameters of the converter, with special attention to the coupled neutronics of the liquid converter and fission target. Calculations performed with the ...

  7. Radioactive ion beams for solid state research

    CERN Document Server

    Correia, J G

    1996-01-01

    Radioactive isotopes are widely used in many research fields. In some applications they are used as tracers after diffusion or after activation in the material itself through nuclear reactions. For research in solid state physics, the ion implantation technique is the most flexible and convenient method to introduce the radioactive isotopes in the materials to be studied, since it allows the control of the ion dose, the implantation depth and the isotopic purity. The on-line coupling of isotope separators to particle accelerators, as is the case of the ISOLDE facility at CERN, allows the obtention of a wide range of high purity short lived isotopes. Currently, the most stringent limitation for some applications is the low acceleration energy of 60 keV of the ISOLDE beam. In this communication a short review of the current applications of the radioactive beams for research in solid state physics at ISOLDE is done. The development of a post-accelerator facility for MeV radioactive ions is introduced and the adv...

  8. Radioactive Ions for Surface Characterization

    CERN Multimedia

    2002-01-01

    The collaboration has completed a set of pilot experiments with the aim to develop techniques for using radioactive nuclei in surface physics. The first result was a method for thermal deposition of isolated atoms (Cd, In, Rb) on clean metallic surfaces. \\\\ \\\\ Then the diffusion history of deposited Cd and In atoms on two model surfaces, Mo(110) and Pd(111), was followed through the electric field gradients (efg) acting at the probe nuclei as measured with the Perturbed Angular Correlation technique. For Mo(110) a rather simple history of the adatoms was inferred from the experiments: Atoms initially landing at terrace sites diffuse from there to ledges and then to kinks, defects always present at real surfaces. The next stage is desorption from the surface. For Pd a scenario that goes still further was found. Following the kink stage the adatoms get incorporated into ledges and finally into the top surface layer. For all these five sites the efg's could be measured.\\\\ \\\\ In preparation for a further series o...

  9. Modeling a neutron rich nuclei source

    Energy Technology Data Exchange (ETDEWEB)

    Mirea, M.; Bajeat, O.; Clapier, F.; Ibrahim, F.; Mueller, A.C.; Pauwels, N.; Proust, J. [Institut de Physique Nucleaire, IN2P3/CNRS, 91 - Orsay (France); Mirea, M. [Institute of Physics and Nuclear Engineering, Tandem Lab., Bucharest (Romania)

    2000-07-01

    The deuteron break-up process in a suitable converter gives rise to intense neutron beams. A source of neutron rich nuclei based on the neutron induced fission can be realised using these beams. A theoretical optimization of such a facility as a function of the incident deuteron energy is reported. The model used to determine the fission products takes into account the excitation energy of the target nucleus and the evaporation of prompt neutrons. Results are presented in connection with a converter-target specific geometry. (author000.

  10. ISOL Beams of Neutron-Rich Oxygen Isotopes

    CERN Document Server

    Köster, U; Bergmann, U; Catherall, R; Cederkäll, J; Dillmann, I; Dubois, M; Durantel, F; Fraile-Prieto, L M; Franchoo, S; Gaubert, G; Gaudefroy, L; Hallmann, O; Huet-Equilbec, C; Jacquot, B; Jardin, P; Kratz, K L; Lecesne, N; Leroy, R; López, A; Maunoury, L; Pacquet, J Y; Pfeiffer, B; Saint-Laurent, M G; Stodel, C; Villari, A C C; Weissman, L

    2005-01-01

    ISOL beams of $19-22^$O were produced at ISOLDE and GANIL. At ISOLDE the neutron-rich oxygen isotopes are produced by 1.4GeV proton-induced reactionsin a UC_X/graphite target. The target is connected via a water-cooled transfer line (to retain all non-volatile isobars) to an ISOLDE type FEBIAD ion source wherethe released CO is dominantly ionized as CO^+, $^19-22$O beams were also produced at SPIRAL (GANIL). A 77.5 MeV/nucleon $^36$S beam was fragmented in a thick graphite target, coupled by a cold tranfer tube to an ECR ion source which ionizes the released CO dominantly as O^+ and CO+.

  11. BEARS: Radioactive ion beams at LBNL

    Energy Technology Data Exchange (ETDEWEB)

    Powell, J.; Guo, F.Q. [Lawrence Berkeley National Lab., CA (United States); Haustein, P.E. [Brookhaven National Lab., Upton, NY (United States). Chemistry Dept.] [and others

    1998-07-01

    BEARS (Berkeley Experiments with Accelerated Radioactive Species) is an initiative to develop a radioactive ion-beam capability at Lawrence Berkeley National Laboratory. The aim is to produce isotopes at an existing medical cyclotron and to accelerate them at the 88 inch Cyclotron. To overcome the 300-meter physical separation of these two accelerators, a carrier-gas transport system will be used. At the terminus of the capillary, the carrier gas will be separated and the isotopes will be injected into the 88 inch Cyclotron`s Electron Cyclotron Resonance (ECR) ion source. The first radioactive beams to be developed will include 20-min {sup 11}C and 70-sec {sup 14}O, produced by (p,n) and (p,{alpha}) reactions on low-Z targets. A test program is currently being conducted at the 88 inch Cyclotron to develop the parts of the BEARS system. Preliminary results of these tests lead to projections of initial {sup 11}C beams of up to 2.5 {times} 10{sup 7} ions/sec and {sup 14}O beams of 3 {times} 10{sup 5} ions/sec.

  12. Superasymmetric fission at intermediate energy and production of neutron-rich nuclei with A

    NARCIS (Netherlands)

    Huhta, M; Dendooven, P; Honkanen, A; Jokinen, A; Lhersonneau, G; Oinonen, M; Penttila, H; Perajarvi, K; Rubchenya, VA; Aysto, J

    1997-01-01

    The yields of neutron-rich Ni, Cu, Zn, Ga and Ge-isotopes were measured in 25 MeV proton induced fission of U-238 using the ion guide-based isotope separator technique. The results indicate enhancement for superasymmetric mass division at intermediate excitation energy of the fissioning nucleus and

  13. Fusion of neutron rich oxygen isotopes in the crust of accreting neutron stars

    CERN Document Server

    Horowitz, C J; Berry, D K

    2007-01-01

    Fusion reactions in the crust of an accreting neutron star are an important source of heat, and the depth at which these reactions occur is important for determining the temperature profile of the star. Fusion reactions depend strongly on the nuclear charge $Z$. Nuclei with $Z\\le 6$ can fuse at low densities in a liquid ocean. However, nuclei with $Z=8$ or 10 may not burn until higher densities where the crust is solid and electron capture has made the nuclei neutron rich. We calculate the $S$ factor for fusion reactions of neutron rich nuclei including $^{24}$O + $^{24}$O and $^{28}$Ne + $^{28}$Ne. We use a simple barrier penetration model. The $S$ factor could be further enhanced by dynamical effects involving the neutron rich skin. This possible enhancement in $S$ should be studied in the laboratory with neutron rich radioactive beams. We model the structure of the crust with molecular dynamics simulations. We find that the crust of accreting neutron stars may contain micro-crystals or regions of phase sep...

  14. The neutrino opacity of neutron rich matter

    Energy Technology Data Exchange (ETDEWEB)

    Alcain, P.N., E-mail: pabloalcain@gmail.com [Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); IFIBA-CONICET (Argentina); Dorso, C.O. [Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); IFIBA-CONICET (Argentina)

    2017-05-15

    The study of neutron rich matter, present in neutron star, proto-neutron stars and core-collapse supernovae, can lead to further understanding of the behavior of nuclear matter in highly asymmetric nuclei. Heterogeneous structures are expected to exist in these systems, often referred to as nuclear pasta. We have carried out a systematic study of neutrino opacity for different thermodynamic conditions in order to assess the impact that the structure has on it. We studied the dynamics of the neutrino opacity of the heterogeneous matter at different thermodynamic conditions with semiclassical molecular dynamics model already used to study nuclear multifragmentation. For different densities, proton fractions and temperature, we calculate the very long range opacity and the cluster distribution. The neutrino opacity is of crucial importance for the evolution of the core-collapse supernovae and the neutrino scattering.

  15. Gamma spectroscopy of neutron rich actinide nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Birkenbach, Benedikt; Geibel, Kerstin; Vogt, Andreas; Hess, Herbert; Reiter, Peter; Steinbach, Tim; Schneiders, David [Koeln Univ. (Germany). IKP; Collaboration: AGATA-Collaboration

    2013-07-01

    Excited states in neutron-rich actinide Th and U nuclei were investigated after multi nucleon transfer reactions employing the AGATA demonstrator and PRISMA setup at LNL (INFN, Italy). A primary {sup 136}Xe beam of 1 GeV hitting a {sup 238}U target was used to produce the nuclei of interest. Beam-like reaction products of Xe- and Ba isotopes after neutron transfer were selected by the PRISMA spectrometer. The recoil like particles were registered by a MCP detector inside the scattering chamber. Coincident γ-rays from excited states in beam and target like particles were measured with the position sensitive AGATA HPGe detectors. Improved Doppler correction and quality of the γ-spectra is based on the novel γ-ray tracking technique which was successfully exploited. First results on the collective properties of various Th and U isotopes are discussed.

  16. Clusters in neutron-rich light nuclei

    Directory of Open Access Journals (Sweden)

    Jelavić Malenica D.

    2016-01-01

    Full Text Available Due to their high selectivity, transfer and sequential decay reactions are powerful tools for studies of both single particle (nucleon and cluster states in light nuclei. Their use is particularly simple for investigations of α-particle clustering (because α-particle has Jπ=0+, which simplifies spin and parity assignments to observed cluster states, but they are also easily applicable to other types of clustering. Recent results on clustering in neutron-rich isotopes of beryllium, boron and carbon obtained measuring the 10B+10B reactions (at 50 and 72 MeV are presented. The highly efficient and segmented detector systems used, built from 4 Double Sided Silicon Strip Detectors (DSSSD allowed detection of double and multiple coincidences and, in that way, studies of states populated in transfer reactions, as well as their sequential decay.

  17. Nuclear astrophysics with radioactive ions at FAIR

    Science.gov (United States)

    Reifarth, R.; Altstadt, S.; Göbel, K.; Heftrich, T.; Heil, M.; Koloczek, A.; Langer, C.; Plag, R.; Pohl, M.; Sonnabend, K.; Weigand, M.; Adachi, T.; Aksouh, F.; Al-Khalili, J.; AlGarawi, M.; AlGhamdi, S.; Alkhazov, G.; Alkhomashi, N.; Alvarez-Pol, H.; Alvarez-Rodriguez, R.; Andreev, V.; Andrei, B.; Atar, L.; Aumann, T.; Avdeichikov, V.; Bacri, C.; Bagchi, S.; Barbieri, C.; Beceiro, S.; Beck, C.; Beinrucker, C.; Belier, G.; Bemmerer, D.; Bendel, M.; Benlliure, J.; Benzoni, G.; Berjillos, R.; Bertini, D.; Bertulani, C.; Bishop, S.; Blasi, N.; Bloch, T.; Blumenfeld, Y.; Bonaccorso, A.; Boretzky, K.; Botvina, A.; Boudard, A.; Boutachkov, P.; Boztosun, I.; Bracco, A.; Brambilla, S.; Briz Monago, J.; Caamano, M.; Caesar, C.; Camera, F.; Casarejos, E.; Catford, W.; Cederkall, J.; Cederwall, B.; Chartier, M.; Chatillon, A.; Cherciu, M.; Chulkov, L.; Coleman-Smith, P.; Cortina-Gil, D.; Crespi, F.; Crespo, R.; Cresswell, J.; Csatlós, M.; Déchery, F.; Davids, B.; Davinson, T.; Derya, V.; Detistov, P.; Diaz Fernandez, P.; DiJulio, D.; Dmitry, S.; Doré, D.; Dueñas, J.; Dupont, E.; Egelhof, P.; Egorova, I.; Elekes, Z.; Enders, J.; Endres, J.; Ershov, S.; Ershova, O.; Fernandez-Dominguez, B.; Fetisov, A.; Fiori, E.; Fomichev, A.; Fonseca, M.; Fraile, L.; Freer, M.; Friese, J.; Borge, M. G.; Galaviz Redondo, D.; Gannon, S.; Garg, U.; Gasparic, I.; Gasques, L.; Gastineau, B.; Geissel, H.; Gernhäuser, R.; Ghosh, T.; Gilbert, M.; Glorius, J.; Golubev, P.; Gorshkov, A.; Gourishetty, A.; Grigorenko, L.; Gulyas, J.; Haiduc, M.; Hammache, F.; Harakeh, M.; Hass, M.; Heine, M.; Hennig, A.; Henriques, A.; Herzberg, R.; Holl, M.; Ignatov, A.; Ignatyuk, A.; Ilieva, S.; Ivanov, M.; Iwasa, N.; Jakobsson, B.; Johansson, H.; Jonson, B.; Joshi, P.; Junghans, A.; Jurado, B.; Körner, G.; Kalantar, N.; Kanungo, R.; Kelic-Heil, A.; Kezzar, K.; Khan, E.; Khanzadeev, A.; Kiselev, O.; Kogimtzis, M.; Körper, D.; Kräckmann, S.; Kröll, T.; Krücken, R.; Krasznahorkay, A.; Kratz, J.; Kresan, D.; Krings, T.; Krumbholz, A.; Krupko, S.; Kulessa, R.; Kumar, S.; Kurz, N.; Kuzmin, E.; Labiche, M.; Langanke, K.; Lazarus, I.; Le Bleis, T.; Lederer, C.; Lemasson, A.; Lemmon, R.; Liberati, V.; Litvinov, Y.; Löher, B.; Lopez Herraiz, J.; Münzenberg, G.; Machado, J.; Maev, E.; Mahata, K.; Mancusi, D.; Marganiec, J.; Martinez Perez, M.; Marusov, V.; Mengoni, D.; Million, B.; Morcelle, V.; Moreno, O.; Movsesyan, A.; Nacher, E.; Najafi, M.; Nakamura, T.; Naqvi, F.; Nikolski, E.; Nilsson, T.; Nociforo, C.; Nolan, P.; Novatsky, B.; Nyman, G.; Ornelas, A.; Palit, R.; Pandit, S.; Panin, V.; Paradela, C.; Parkar, V.; Paschalis, S.; Pawłowski, P.; Perea, A.; Pereira, J.; Petrache, C.; Petri, M.; Pickstone, S.; Pietralla, N.; Pietri, S.; Pivovarov, Y.; Potlog, P.; Prokofiev, A.; Rastrepina, G.; Rauscher, T.; Ribeiro, G.; Ricciardi, M.; Richter, A.; Rigollet, C.; Riisager, K.; Rios, A.; Ritter, C.; Rodriguez Frutos, T.; Rodriguez Vignote, J.; Röder, M.; Romig, C.; Rossi, D.; Roussel-Chomaz, P.; Rout, P.; Roy, S.; Söderström, P.; Saha Sarkar, M.; Sakuta, S.; Salsac, M.; Sampson, J.; Sanchez, J.; Rio Saez, del; Sanchez Rosado, J.; Sanjari, S.; Sarriguren, P.; Sauerwein, A.; Savran, D.; Scheidenberger, C.; Scheit, H.; Schmidt, S.; Schmitt, C.; Schnorrenberger, L.; Schrock, P.; Schwengner, R.; Seddon, D.; Sherrill, B.; Shrivastava, A.; Sidorchuk, S.; Silva, J.; Simon, H.; Simpson, E.; Singh, P.; Slobodan, D.; Sohler, D.; Spieker, M.; Stach, D.; Stan, E.; Stanoiu, M.; Stepantsov, S.; Stevenson, P.; Strieder, F.; Stuhl, L.; Suda, T.; Sümmerer, K.; Streicher, B.; Taieb, J.; Takechi, M.; Tanihata, I.; Taylor, J.; Tengblad, O.; Ter-Akopian, G.; Terashima, S.; Teubig, P.; Thies, R.; Thoennessen, M.; Thomas, T.; Thornhill, J.; Thungstrom, G.; Timar, J.; Togano, Y.; Tomohiro, U.; Tornyi, T.; Tostevin, J.; Townsley, C.; Trautmann, W.; Trivedi, T.; Typel, S.; Uberseder, E.; Udias, J.; Uesaka, T.; Uvarov, L.; Vajta, Z.; Velho, P.; Vikhrov, V.; Volknandt, M.; Volkov, V.; von Neumann-Cosel, P.; von Schmid, M.; Wagner, A.; Wamers, F.; Weick, H.; Wells, D.; Westerberg, L.; Wieland, O.; Wiescher, M.; Wimmer, C.; Wimmer, K.; Winfield, J. S.; Winkel, M.; Woods, P.; Wyss, R.; Yakorev, D.; Yavor, M.; Zamora Cardona, J.; Zartova, I.; Zerguerras, T.; Zgura, M.; Zhdanov, A.; Zhukov, M.; Zieblinski, M.; Zilges, A.; Zuber, K.

    2016-01-01

    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 flow and r-process, β-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 offer 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.

  18. Nuclear astrophysics with radioactive ions at FAIR

    CERN Document Server

    Reifarth, R; Göbel, K; Heftrich, T; Heil, M; Koloczek, A; Langer, C; Plag, R; Pohl, M; Sonnabend, K; Weigand, M; Adachi, T; Aksouh, F; Al-Khalili, J; AlGarawi, M; AlGhamdi, S; Alkhazov, G; Alkhomashi, N; Alvarez-Pol, H; Alvarez-Rodriguez, R; Andreev, V; Andrei, B; Atar, L; Aumann, T; Avdeichikov, V; Bacri, C; Bagchi, S; Barbieri, C; Beceiro, S; Beck, C; Beinrucker, C; Belier, G; Bemmerer, D; Bendel, M; Benlliure, J; Benzoni, G; Berjillos, R; Bertini, D; Bertulani, C; Bishop, S; Blasi, N; Bloch, T; Blumenfeld, Y; Bonaccorso, A; Boretzky, K; Botvina, A; Boudard, A; Boutachkov, P; Boztosun, I; Bracco, A; Brambilla, S; Monago, J Briz; Caamano, M; Caesar, C; Camera, F; Casarejos, E; Catford, W; Cederkall, J; Cederwall, B; Chartier, M; Chatillon, A; Cherciu, M; Chulkov, L; Coleman-Smith, P; Cortina-Gil, D; Crespi, F; Crespo, R; Cresswell, J; Csatlós, M; Déchery, F; Davids, B; Davinson, T; Derya, V; Detistov, P; Fernandez, P Diaz; DiJulio, D; Dmitry, S; Doré, D; nas, J Due\\; Dupont, E; Egelhof, P; Egorova, I; Elekes, Z; Enders, J; Endres, J; Ershov, S; Ershova, O; Fernandez-Dominguez, B; Fetisov, A; Fiori, E; Fomichev, A; Fonseca, M; Fraile, L; Freer, M; Friese, J; Borge, M G; Redondo, D Galaviz; Gannon, S; Garg, U; Gasparic, I; Gasques, L; Gastineau, B; Geissel, H; Gernhäuser, R; Ghosh, T; Gilbert, M; Glorius, J; Golubev, P; Gorshkov, A; Gourishetty, A; Grigorenko, L; Gulyas, J; Haiduc, M; Hammache, F; Harakeh, M; Hass, M; Heine, M; Hennig, A; Henriques, A; Herzberg, R; Holl, M; Ignatov, A; Ignatyuk, A; Ilieva, S; Ivanov, M; Iwasa, N; Jakobsson, B; Johansson, H; Jonson, B; Joshi, P; Junghans, A; Jurado, B; Körner, G; Kalantar, N; Kanungo, R; Kelic-Heil, A; Kezzar, K; Khan, E; Khanzadeev, A; Kiselev, O; Kogimtzis, M; Körper, D; Kräckmann, S; Kröll, T; Krücken, R; Krasznahorkay, A; Kratz, J; Kresan, D; Krings, T; Krumbholz, A; Krupko, S; Kulessa, R; Kumar, S; Kurz, N; Kuzmin, E; Labiche, M; Langanke, K; Lazarus, I; Bleis, T Le; Lederer, C; Lemasson, A; Lemmon, R; Liberati, V; Litvinov, Y; Löher, B; Herraiz, J Lopez; Münzenberg, G; Machado, J; Maev, E; Mahata, K; Mancusi, D; Marganiec, J; Perez, M Martinez; Marusov, V; Mengoni, D; Million, B; Morcelle, V; Moreno, O; Movsesyan, A; Nacher, E; Najafi, M; Nakamura, T; Naqvi, F; Nikolski, E; Nilsson, T; Nociforo, C; Nolan, P; Novatsky, B; Nyman, G; Ornelas, A; Palit, R; Pandit, S; Panin, V; Paradela, C; Parkar, V; Paschalis, S; Paw\\lowski, P; Perea, A; Pereira, J; Petrache, C; Petri, M; Pickstone, S; Pietralla, N; Pietri, S; Pivovarov, Y; Potlog, P; Prokofiev, A; Rastrepina, G; Rauscher, T; Ribeiro, G; Ricciardi, M; Richter, A; Rigollet, C; Riisager, K; Rios, A; Ritter, C; Frutos, T Rodríguez; Vignote, J Rodriguez; Röder, M; Romig, C; Rossi, D; Roussel-Chomaz, P; Rout, P; Roy, S; Söderström, P; Sarkar, M Saha; Sakuta, S; Salsac, M; Sampson, J; Saez, J Sanchez del Rio; Rosado, J Sanchez; Sanjari, S; Sarriguren, P; Sauerwein, A; Savran, D; Scheidenberger, C; Scheit, H; Schmidt, S; Schmitt, C; Schnorrenberger, L; Schrock, P; Schwengner, R; Seddon, D; Sherrill, B; Shrivastava, A; Sidorchuk, S; Silva, J; Simon, H; Simpson, E; Singh, P; Slobodan, D; Sohler, D; Spieker, M; Stach, D; Stan, E; Stanoiu, M; Stepantsov, S; Stevenson, P; Strieder, F; Stuhl, L; Suda, T; Sümmerer, K; Streicher, B; Taieb, J; Takechi, M; Tanihata, I; Taylor, J; Tengblad, O; Ter-Akopian, G; Terashima, S; Teubig, P; Thies, R; Thoennessen, M; Thomas, T; Thornhill, J; Thungstrom, G; Timar, J; Togano, Y; Tomohiro, U; Tornyi, T; Tostevin, J; Townsley, C; Trautmann, W; Trivedi, T; Typel, S; Uberseder, E; Udias, J; Uesaka, T; Uvarov, L; Vajta, Z; Velho, P; Vikhrov, V; Volknandt, M; Volkov, V; von Neumann-Cosel, P; von Schmid, M; Wagner, A; Wamers, F; Weick, H; Wells, D; Westerberg, L; Wieland, O; Wiescher, M; Wimmer, C; Wimmer, K; Winfield, J S; Winkel, M; Woods, P; Wyss, R; Yakorev, D; Yavor, M; Cardona, J Zamora; Zartova, I; Zerguerras, T; Zgura, I; Zhdanov, A; Zhukov, M; Zieblinski, M; Zilges, A; Zuber, K

    2016-01-01

    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 flow and r-process beta-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 offer 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.

  19. Unexpectedly large charge radii of neutron-rich calcium isotopes

    CERN Document Server

    Garcia Ruiz, R F; Blaum, K; Ekström, A; Frömmgen, N; Hagen, G; Hammen, M; Hebeler, K; Holt, J D; Jansen, G R; Kowalska, M; Kreim, K; Nazarewicz, W; Neugart, R; Neyens, G; Nörtershäuser, W; Papenbrock, T; Papuga, J; Schwenk, A; Simonis, J; Wendt, K A; Yordanov, D T

    2016-01-01

    Despite being a complex many-body system, the atomic nucleus exhibits simple structures for certain ‘magic’ numbers of protons and neutrons. The calcium chain in particular is both unique and puzzling: evidence of doubly magic features are known in 40,48Ca, and recently suggested in two radioactive isotopes, 52,54Ca. Although many properties of experimentally known calcium isotopes have been successfully described by nuclear theory, it is still a challenge to predict the evolution of their charge radii. Here we present the first measurements of the charge radii of 49,51,52Ca, obtained from laser spectroscopy experiments at ISOLDE, CERN. The experimental results are complemented by state-of-the-art theoretical calculations. The large and unexpected increase of the size of the neutron-rich calcium isotopes beyond N = 28 challenges the doubly magic nature of 52Ca and opens new intriguing questions on the evolution of nuclear sizes away from stability, which are of importance for our understanding of neutron-...

  20. Fusion Enhancement for Neutron-Rich Light Nuclei

    CERN Document Server

    Singh, Varinderjit; Steinbach, T K; Hudan, S; deSouza, R T; Baby, L T; Kuvin, S A; Tripathi, V; Wiedenhover, I

    2016-01-01

    Measurement of the fusion cross-section for neutron-rich light nuclei is crucial in ascertaining if fusion of these nuclei occurs in the outer crust of a neutron star. The fusion excitation function at near-barrier energies for the $^{19}$O + $^{12}$C system was measured and the experimental results are compared to the fusion excitation function of $^{18}$O + $^{12}$C and $^{16}$O + $^{12}$C. The experiment was performed by utilizing a beam of $^{19}$O, produced via the $^{18}$O(d,p) reaction, to bombard a $^{12}$C target at energies near the Coulomb barrier. Evaporation residues produced in fusion of $^{18,19}$O ions with $^{12}$C target nuclei were detected with good geometric efficiency and identified by measuring their energy and time-of-flight. A significant enhancement is observed in the fusion probability of $^{19}$O ions with a $^{12}$C target as compared to $^{18}$O ions. The larger cross-sections observed at near barrier energies is related to significant narrowing of the fusion barrier indicating a...

  1. Nuclear Structure Studies of Exotic Nuclei with Radioactive Ion Beams A Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Winger, Jeff Allen [Mississippi State Univ., Mississippi State, MS (United States)

    2016-04-21

    Beta-decay spectroscopy provides important information on nuclear structure and properties needed to understand topics as widely varied as fundamental nuclear astrophysics to applied nuclear reactor design. However, there are significant limitations of our knowledge due to an inability to experimentally measure everything. Therefore, it is often necessary to rely on theoretical calculations which need to be vetted with experimental results. The focus of this report will be results from experimental research performed by the Principal Investigator (PI) and his research group at Mississippi State University in which the group played the lead role in proposing, implementing, performing and analyzing the experiment. This research was carried out at both the National Superconduction Cyclotron Laboratory (NSCL) at Michigan State University and the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. The primary emphasis of the research was the use of \\bdec spectroscopy as a tool to understand the evolution of nuclear structure in neutron-rich nuclei which could then be applied to improve theory and to increase the overall knowledge of nuclear structure.

  2. Wien filter for cooled low-energy radioactive ion beams

    NARCIS (Netherlands)

    Nummela, S; Dendooven, P; Heikkinen, P; Huikari, J; Nieminen, A; Jokinen, A; Rinta-Antila, S; Rubchenya, V.; Aysto, J

    2002-01-01

    A Wien filter for cooled radioactive ion beams has been designed at Ion Guide Isotope Separator On Line technique (IGISOL). The purpose of such device is to eliminate doubly charged ions from the mass separated singly charged ions, based on q = +2-->q = +1 charge exchange process in an ion cooler, T

  3. Target development for a radioactive ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M.; Vanhorenbeeck, J. (Universite Libre de Bruxelles (Belgium). Inst. d' Astronomie et d' Astrophysique); Baeten, F.; Dom, C. (Institut National des Radioelements, Fleurus (Belgium)); Darquennes, D.; Delbar, T.; Jongen, Y.; Lacroix, M.; Lipnik, P.; Loiselet, M.; Ryckewaert, G.; Wa Kitwanga, S.; Vervier, J.; Zaremba, S. (Louvain Univ., Louvain-la-Neuve (Belgium). Centre de Physique Nucleaire; Louvain Univ., Louvain-la-Neuve (Belgium). Lab. de Cyclotron); Huyse, M.; Reusen, G.; Duppen, P. van (Leuven Univ. (Belgium). Inst. voor Kern- en Stralingsfysika)

    1989-10-01

    A proton bombarded target coupled to an ion source is a key-equipment to produce a cyclotron accelerated Radioactive Ion Beam (RIB). This note concerns the target development for a {sup 13}N ion beam which will be the first one out of a more general project at Louvain-la-Neuve (Report RIB-1988-01). A 30-MeV proton beam of up to 300-{mu}A intensity from the CYCLONE 30 bombards a graphite target to produce the {sup 13}N isotope via the {sup 13}C(p, n){sup 13}N reaction. Two major problems have to be solved: The extraction and transport of {sup 13}N and the beam-heat dissipation. These aspects are somewhat correlated to the temperature dependence of the {sup 13}N release and to the heat conductivity of graphite. A disk shaped target can be cooled through its side-face or through its back-face, and in fact both designs are explored. The extraction yield of the first one varies with the beam intensity up to a maximum value of 46% at 170 {mu}A. For the second one, which is presently under development, the target temperature can be adjusted by a cooled finger of variable length. (orig.).

  4. Penning trap assisted decay spectroscopy of neutron-rich {sup 115}Ru

    Energy Technology Data Exchange (ETDEWEB)

    Kurpeta, J.; Plochocki, A.; Urban, W. [Warsaw University, Faculty of Physics, Warsaw (Poland); Elomaa, V.V.; Eronen, T.; Hakala, J.; Jokinen, A.; Karvonen, P.; Moore, I.; Penttilae, H.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Ronkainen, J.; Saastamoinen, A.; Sonoda, T.; Weber, C.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics (Finland)

    2007-03-15

    Exotic, neutron-rich {sup 111}Mo and {sup 115}Ru nuclei, produced in proton-induced fission of {sup 238}U target, were separated with the IGISOL mass separator. The separator was coupled to the JYFLTRAP Penning trap to select the ions of a single, desired element out of the isobaric IGISOL beam. Monoisotopic samples of {sup 115}Ru and {sup 111}Mo ions were observed with a microchannel plate detector after the trap or were implanted on a catcher foil for gamma- and beta-ray coincidence spectroscopy. In spite of short data taking time new gamma transitions were identified in the beta decay of very neutron-rich {sup 115}Ru. (orig.)

  5. The First On-line Radioactive Ion Beam from BRIF

    Institute of Scientific and Technical Information of China (English)

    CUI; Bao-qun; MA; Ying-jun; MA; Rui-gang; TANG; Bing; HUANG; Qing-hua; CHEN; Li-hua; MA; Xie

    2015-01-01

    Many of the reactions fundamentally important in nuclear physics and astrophysics can only be studied with high energy radioactive ion beams (RIBs).Radioactive ion beams offer unique opportunities to further our knowledge about the structure of the nucleus,the stellar processes.

  6. Transport and extraction of radioactive ions stopped in superfluid helium

    NARCIS (Netherlands)

    Huang, WX; Dendooven, P; Gloos, K; Takahashi, N; Arutyunov, K; Pekola, JP; Aysto, J

    2003-01-01

    A new approach to convert a high energy beam to a low energy one, which is essential for the next generation radioactive ion beam facilities, has been proposed and tested at Jyvaskyla, Finland. An open Ra-223 alpha-decay-recoil source has been used to produce radioactive ions in superfluid helium. T

  7. From laser particle acceleration to the synthesis of extremely neutron rich isotopes via the novel fission-fusion mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Thirolf, P. G., E-mail: Peter.Thirolf@lmu.de [Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching (Germany)

    2015-02-24

    High-power, short pulse lasers have emerged in the last decade as attractive tools for accelerating charged particles (electrons, ions) to high energies over mm-scale acceleration lengths, thus promising to rival conventional acceleration techniques in the years ahead. In the first part of the article, the principles of laser-plasma interaction as well as the techniques and the current status of the acceleration of electron and ion beams will be briefly introduced. In particular with the upcoming next generation of multi-PW class laser systems, such as the one under construction for the ELI-Nuclear Physics project in Bucharest (ELI-NP), very efficient acceleration mechanisms for brilliant ion beams like radiation pressure acceleration (RPA) come into reach. Here, ultra-dense ion beams reaching solid-state density can be accelerated from thin target foils, exceeding the density of conventionally accelerated ion beams by about 14 orders of magnitude. This unique property of laser-accelerated ion beams can be exploited to explore the scenario of a new reaction mechanism called ‘fission-fusion’, which will be introduced in the second part of the article. Accelerating fissile species (e.g. {sup 232}Th) towards a second layer of the same material will lead to fission both of the beam-like and target-like particles. Due to the close to solid-state density of the accelerated ion bunches, fusion may occur between neutron-rich (light) fission products. This may open an access path towards extremely neutron-rich nuclides in the vicinity of the N=126 waiting point of the astrophysical r process. ‘Waiting points’ at closed nucleon shells play a crucial role in controlling the reaction rates. However, since most of the pathway of heavy-element formation via the rapid-neutron capture process (r-process) runs in ‘terra incognita’ of the nuclear landscape, in particular the waiting point at N=126 is yet unexplored and will remain largely inaccessible to conventional

  8. Production of neutron-rich isotopes in {sup 82}Se+{sup 238}U grazing reaction

    Energy Technology Data Exchange (ETDEWEB)

    Marginean, N.; Corradi, L. [INFN, Laboratori Nazionali di Legnaro Padova (Italy); Berghini, S. [National Institute for Physics and Nuclear Engineering, Bucharest (Romania)] (and others)

    2005-07-01

    The reactions at the grazing angle between heavy ions at energies close to the Coulomb barrier are presently considered as a valuable tool for the production of nuclei far from stability, particularly in the neutron-rich area. Recent high mass-resolution experiments demonstrated that one could observe the transfer of up to six proton stripping (-6p) and six neutron pick-up (+6n) channels with cross sections down to {approx}50-100 {mu}b.

  9. Precision mass measurements at TITAN with radioactive ions

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowski, A.A., E-mail: aniak@triumf.ca [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Macdonald, T.D. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Andreoiu, C. [Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Bale, J.C. [Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6 (Canada); Brunner, T.; Chaudhuri, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Chowdhury, U. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada); Ettenauer, S.; Gallant, A.T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Grossheim, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Lennarz, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Institut für Kernphysik, Westfälische Wilhelms-Universität, D-48149 Münster (Germany); Mané, E.; Pearson, M.R.; Schultz, B.E.; Simon, M.C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Simon, V.V. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Fakultät für Physik und Astronomie, Ruprecht-Karls-Universität, 61920 Heidelberg (Germany); Dilling, J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

    2013-12-15

    Highlights: • The TITAN facility is the sole online Penning trap mass spectrometer with charge breeding capabilities. • Use of highly charged exotic ions reduces the beam time requirements. • Threshold charge breeding was developed as a novel technique to separate isobaric species. • Recent mass measurements have been performed to investigate nuclear structure, tests of electroweak theory, and neutrino physics. -- Abstract: Measurements of the atomic mass further our understanding in many disciplines from metrology to physics beyond the standard model. The accuracy and precision of Penning trap mass spectrometry have been well demonstrated at TITAN, including measurements of neutron-rich calcium and potassium isotopes to investigate three-body forces in nuclear structure and within the island of inversion to study the mechanism of shell quenching and deformation. By charge breeding ions, TITAN has enhanced the precision of the measurement technique. The precision achieved in the measurement of the superallowed β-emitter {sup 74}Rb in the 8+ charge state rivaled earlier measurements with singly charged ions in a fraction of the time. By breeding {sup 78}Rb to the same charge state, the ground state could be easily distinguished from the isomer. Further developments led to threshold charge breeding, which permitted capturing and measuring isobarically and elementally pure ion samples in the Penning trap. This was demonstrated via the Q-value determination of {sup 71}Ge. An overview of the TITAN facility and recent results are presented herein.

  10. Mass measurements of neutron-rich Rb and Sr isotopes

    CERN Document Server

    Klawitter, R; Brodeur, M; Chowdhury, U; Chausdhuri, A; Fallis, J; Gallant, A T; Grossheim, A; Kwiatkowski, A A; Lascar, D; Leach, K G; Lennarz, A; Macdonald, T D; Pearkes, J; Seeraji, S; Simon, M C; Simon, V V; Schultz, B E; Dilling, J

    2015-01-01

    We report on the mass measurements of several neutron-rich $\\mathrm{Rb}$ and $\\mathrm{Sr}$ isotopes in the $A \\approx 100$ region with the TITAN Penning-trap mass spectrometer. Using highly charged ions in the charge state $q=10+$, the masses of $^{98,99}\\mathrm{Rb}$ and $^{98-100}\\mathrm{Sr}$ have been determined with a precision of $6 - 12\\ \\mathrm{keV}$, making their uncertainty negligible for r-process nucleosynthesis network calculations. The mass of $^{101}\\mathrm{Sr}$ has been determined directly for the first time with a precision eight times higher than the previous indirect measurement and a deviation of $3\\sigma$ when compared to the Atomic Mass Evaluation. We also confirm the mass of $^{100}\\mathrm{Rb}$ from a previous measurement. Furthermore, our data indicates the existance of a low-lying isomer with $80\\ \\mathrm{keV}$ excitation energy in $^{98}\\mathrm{Rb}$. We show that our updated mass values lead to minor changes in the r-process by calculating fractional abundances in the $A\\approx 100$ re...

  11. Shape coexistence in neutron-rich strontium isotopes at N = 60

    Science.gov (United States)

    Clément, E.; Zielińska, M.

    2017-08-01

    The structure of neutron-rich {}{96,98}Sr nuclei was investigated by low-energy Coulomb excitation of radioactive beams at the REX-ISOLDE facility, CERN, with the MINIBALL spectrometer. The results support the scenario of a shape transition at N = 60, giving rise to the coexistence of a highly deformed prolate and a spherical configuration in 98Sr with low configuration mixing. They are discussed in the context of systematics of quadrupole moments and transition probabilities in the N = 60 region.

  12. High-accuracy mass measurements of neutron-rich Kr isotopes

    CERN Document Server

    Delahaye, P; Blaum, K; Carrel, F; George, S; Herfurth, F; Herlert, A; Kellerbauer, A G; Kluge, H J; Lunney, D; Schweikhard, L; Yazidjian, C

    2006-01-01

    The atomic masses of the neutron-rich krypton isotopes 84,86-95Kr have been determined with the tandem Penning trap mass spectrometer ISOLTRAP with uncertainties ranging from 20 to 220 ppb. The masses of the short-lived isotopes 94Kr and 95Kr were measured for the first time. The masses of the radioactive nuclides 89Kr and 91Kr disagree by 4 and 6 standard deviations, respectively, from the present Atomic-Mass Evaluation database. The resulting modification of the mass surface with respect to the two-neutron separation energies as well as implications for mass models and stellar nucleosynthesis are discussed.

  13. The production of accelerated radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D.K.

    1993-11-01

    During the last few years, substantial work has been done and interest developed in the scientific opportunities available with accelerated radioactive ion beams (RIBs) for nuclear physics, astrophysics, and applied research. This interest has led to the construction, development, and proposed development of both first- and second-generation RIB facilities in Asia, North America, and Europe; international conferences on RIBs at Berkeley and Louvain-la-Neuve; and many workshops on specific aspects of RIB production and science. This paper provides a discussion of both the projectile fragmentation, PF, and isotope separator on-line, ISOL, approach to RIB production with particular emphasis on the latter approach, which employs a postaccelerator and is most suitable for nuclear structure physics. The existing, under construction, and proposed facilities worldwide are discussed. The paper draws heavily from the CERN ISOLDE work, the North American IsoSpin Laboratory (ISL) study, and the operating first-generation RIB facility at Louvain-la-Neuve, and the first-generation RIB project currently being constructed at ORNL.

  14. A radioactive ion beam facility using photofission

    CERN Document Server

    Diamond, W T

    1999-01-01

    Use of a high-power electron linac as the driver accelerator for a Radioactive Ion Beam (RIB) facility is proposed. An electron beam of 30 MeV and 100 kW can produce nearly 5x10 sup 1 sup 3 fissions/s from an optimized sup 2 sup 3 sup 5 U target and about 60% of this from a natural uranium target. An electron beam can be readily transmitted through a thin window at the exit of the accelerator vacuum system and transported a short distance through air to a water-cooled Bremsstrahlung-production target. The Bremsstrahlung radiation can, in turn, be transported through air to the isotope-production target. This separates the accelerator vacuum system, the Bremsstrahlung target and the isotope-production target, reducing remote handling problems. The electron beam can be scanned over a large target area to reduce the power density on both the Bremsstrahlung and isotope-production targets. These features address one of the most pressing technological challenges of a high-power RIB facility, namely the production o...

  15. Improvements and developments on radioactive ion beam line in Lanzhou

    CERN Document Server

    Guo Zhong Yan; Xiao Guo Qing; Xu Hu Shan; Sun Zhi Yu; Li Jia Xing; Wang Meng; Chen Zhi Qiang; Mao Rui Shi; Wang Wu Sheng; Bai Jie; Hu Zheng Guo; Chen Li Xin; Li Chen

    2003-01-01

    The improvements and the developments on radioactive ion beam line in Lanzhou (RIBLL) were carried out. So the performances of RIBLL are toned up evidently. It makes operating and setting RIBLL convenient and reliable

  16. Multi-messenger observations of neutron rich matter

    CERN Document Server

    Horowitz, C J

    2011-01-01

    Neutron rich matter is central to many fundamental questions in nuclear physics and astrophysics. Moreover, this material is being studied with an extraordinary variety of new tools such as the Facility for Rare Isotope Beams (FRIB) and the Laser Interferometer Gravitational Wave Observatory (LIGO). We describe the Lead Radius Experiment (PREX) that uses parity violating electron scattering to measure the neutron radius in $^{208}$Pb. This has important implications for neutron stars and their crusts. We discuss X-ray observations of neutron star radii. These also have important implications for neutron rich matter. Gravitational waves (GW) open a new window on neutron rich matter. They come from sources such as neutron star mergers, rotating neutron star mountains, and collective r-mode oscillations. Using large scale molecular dynamics simulations, we find neutron star crust to be very strong. It can support mountains on rotating neutron stars large enough to generate detectable gravitational waves. Finally...

  17. Properties of neutron-rich hafnium high-spin isomers

    CERN Document Server

    Tungate, G; Walker, P M; Neyens, G; Billowes, J; Flanagan, K; Koester, U H; Litvinov, Y

    It is proposed to study highly-excited multi-quasiparticle isomers in neutron-rich hafnium (Z=72) isotopes. Long half-lives have already been measured for such isomers in the storage ring at GSI, ensuring their accessibility with ISOL production. The present proposal focuses on:\\\\ (i) an on-line experiment to measure isomer properties in $^{183}$Hf and $^{184}$Hf, and\\\\ (ii) an off-line molecular breakup test using REXTRAP, to provide Hf$^{+}$ beams for future laser spectroscopy and greater sensitivity for the future study of more neutron-rich isotopes.

  18. Modes of decay in neutron-rich nuclei

    CERN Document Server

    Kumar, B; Singh, S K; Lahiri, C; Patra, S K

    2016-01-01

    We calculate the ground, first intrinsic excited states and density distribution for neutron-rich thorium and uranium isotopes, within the framework of relativistic mean field(RMF) approach using axially deformed basis. The total nucleon densities are calculated, from which the cluster-structures inside the parent nuclei are determined. The possible modes of decay, like {\\alpha}-decay and \\b{eta} -decay are analyzed. We find the neutron-rich isotopes are stable against {\\alpha}-decay, however they are very much unstable against \\b{eta} -decay. The life time of these nuclei predicted to be tens of second against \\b{eta} -decay.

  19. Modes of decay in neutron-rich nuclei

    Science.gov (United States)

    Kumar, B.; Biswal, S. K.; Singh, S. K.; Lahiri, C.; Patra, S. K.

    2016-03-01

    We calculate the ground, first intrinsic excited states and density distribution for neutron-rich thorium and uranium isotopes, within the framework of relativistic mean field (RMF) approach using axially deformed basis. The total nucleon densities are calculated, from which the cluster-structures inside the parent nuclei are determined. The possible modes of decay, like α-decay and β-decay are analyzed. We find the neutron-rich isotopes are stable against α-decay, however they are very much unstable against β-decay. The life time of these nuclei predicted to be tens of second against β-decay.

  20. Wien filter for cooled low-energy radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Nummela, S. E-mail: saara.nummela@phys.jyu.fi; Dendooven, P.; Heikkinen, P.; Huikari, J.; Nieminen, A.; Jokinen, A.; Rinta-Antila, S.; Rubchenya, V.; Aeystoe, J

    2002-04-01

    A Wien filter for cooled radioactive ion beams has been designed at Ion Guide Isotope Separator On Line technique (IGISOL). The purpose of such device is to eliminate doubly charged ions from the mass separated singly charged ions, based on q=+2{yields}q=+1 charge exchange process in an ion cooler. The performance of the Wien filter has been tested off-line with a discharge ion source as well as on-line with a radioactive beam. The electron capture process of cooled q=+2 ions has been investigated in a radiofrequency quadrupole ion cooler with varying partial pressures of nitrogen. Also, the superasymmetric fission production yields of 68

  1. Transport and extraction of radioactive ions stopped in superfluid helium

    CERN Document Server

    Huang Wan Xia; Gloos, K; Takahashi, N; Arutyunov, K; Pekola, J P; Äystö, J

    2003-01-01

    A new approach to convert a high energy beam to a low energy one, which is essential for the next generation radioactive ion beam facilities, has been proposed and tested at Jyvaeskylae, Finland. An open sup 2 sup 2 sup 3 Ra alpha-decay-recoil source has been used to produce radioactive ions in superfluid helium. The alpha spectra demonstrate that the recoiling sup 2 sup 1 sup 9 Rn ions have been extracted out of liquid helium. This first observation of the extraction of heavy positive ions across the superfluid helium surface was possible thanks to the high sensitivity of radioactivity detection. An efficiency of 36% was obtained for the ion extraction out of liquid helium.

  2. Statistical Spectroscopy for Neutron-rich sd-Shell Nuclei

    CERN Document Server

    Kar, Kamales

    2012-01-01

    Statistical spectroscopic results using the spectral distribution theory are obtained for the structure of neutron-rich light nuclei going towards the drip line and compared to experimental values available. These results will be useful for nuclear astrophysics problems where often averaged nuclear properties are adequate.

  3. β-Decay of Light Neutron-Rich Nuclei

    Institute of Scientific and Technical Information of China (English)

    何超; 华辉; 李湘庆; 汪波

    2012-01-01

    The β-decays of neutron-rich carbon, nitrogen and fluorine isotopes have been systematically studied using the OXBASH shell Model. In the psd, spsd and spsdpf model space, we use the WBP interaction to calculate the half-lives and neutron emission probabilities of neutron- rich carbon and nitrogen isotopes, respectively. With the USD (W) and CW interactions, we calculate the half-lives and neutron emission probabilities of neutron-rich fluorine isotope in the sd model space, respectively. The calculated half-lives and neutron emission probabilities reproduce recent experimental data very well. It seems to show that the particles of the neutron-rich carbon and nitrogen isotopes are mainly excited in the spsd space. The β-decay of 21N to the neutron bound states in 210 is mostly the first forbidden transition which makes the neutron emission probability increase. The theoretical calculation of β-decay of 25F to 25Ne with CW interaction shows that CW interaction is better than USD interaction.

  4. Haloes and clustering in light, neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Orr, N.A

    2001-10-01

    Clustering is a relatively widespread phenomenon which takes on many guises across the nuclear landscape. Selected topics concerning the study of halo systems and clustering in light, neutron-rich nuclei are discussed here through illustrative examples taken from the Be isotopic chain. (author)

  5. Recent results on neutron rich tin isotopes by laser spectroscopy

    CERN Document Server

    Roussière, B; Crawford, J E; Essabaa, S; Fedosseev, V; Geithner, W; Genevey, J; Girod, M; Huber, G; Horn, R; Kappertz, S; Lassen, J; Le Blanc, F; Lee, J K P; Le Scornet, G; Lettry, Jacques; Mishin, V I; Neugart, R; Obert, J; Oms, J; Ouchrif, A; Peru, S; Pinard, J; Ravn, H L; Sauvage, J; Verney, D

    2001-01-01

    Laser spectroscopy measurements have been performed on neutron rich tin isotopes using the COMPLIS experimental setup. The nuclear charge radii of the even-even isotopes from A=108 to 132 are compared to the results of macroscopic and microscopic calculations. The improvements and optimizations needed to perform the isotope shift measurement on $^{134}$Sn are presented.

  6. In-Trap Spectroscopy of Charge-Bred Radioactive Ions

    Science.gov (United States)

    Lennarz, A.; Grossheim, A.; Leach, K. G.; Alanssari, M.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Crespo López-Urrutia, J. R.; Gallant, A. T.; Holl, M.; Kwiatkowski, A. A.; Lassen, J.; Macdonald, T. D.; Schultz, B. E.; Seeraji, S.; Simon, M. C.; Andreoiu, C.; Dilling, J.; Frekers, D.

    2014-08-01

    In this Letter, we introduce the concept of in-trap nuclear decay spectroscopy of highly charged radioactive ions and describe its successful application as a novel spectroscopic tool. This is demonstrated by a measurement of the decay properties of radioactive mass A=124 ions (here, In124 and Cs124) in the electron-beam ion trap of the TITAN facility at TRIUMF. By subjecting the trapped ions to an intense electron beam, the ions are charge bred to high charge states (i.e., equivalent to the removal of N-shell electrons), and an increase of storage times to the level of minutes without significant ion losses is achieved. The present technique opens the venue for precision spectroscopy of low branching ratios and is being developed in the context of measuring electron-capture branching ratios needed for determining the nuclear ground-state properties of the intermediate odd-odd nuclei in double-beta (ββ) decay.

  7. Nuclear astrophysics with radioactive ions at FAIR

    OpenAIRE

    2016-01-01

    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 flow and r-process beta-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 ...

  8. Decay Pattern of Pygmy States Observed in Neutron-Rich Ne26

    Science.gov (United States)

    Gibelin, J.; Beaumel, D.; Motobayashi, T.; Blumenfeld, Y.; Aoi, N.; Baba, H.; Elekes, Z.; Fortier, S.; Frascaria, N.; Fukuda, N.; Gomi, T.; Ishikawa, K.; Kondo, Y.; Kubo, T.; Lima, V.; Nakamura, T.; Saito, A.; Satou, Y.; Scarpaci, J.-A.; Takeshita, E.; Takeuchi, S.; Teranishi, T.; Togano, Y.; Vinodkumar, A. M.; Yanagisawa, Y.; Yoshida, K.

    2008-11-01

    Coulomb excitation of the exotic neutron-rich nucleus Ne26 on a Pb208 target was measured at 58MeV/u in order to search for low-lying E1 strength above the neutron emission threshold. This radioactive beam experiment was carried out at the RIKEN Accelerator Research Facility. Using the invariant mass method in the Ne25+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV excitation energy. By performing a multipole decomposition of the differential cross section, a reduced dipole transition probability of B(E1)=0.49±0.16e2fm2 is deduced, corresponding to 4.9±1.6% of the Thomas-Reiche-Kuhn sum rule. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is measured. The extracted decay pattern is not consistent with several mean-field theory descriptions of the pygmy states.

  9. Simulation of induced radioactivity for Heavy Ion Medical Machine

    CERN Document Server

    Jun-Kui, Xu; Wu-Yuan, Li; Wang, Mao; Jia-Wen, Xia; Xi-Meng, Chen; Wei-Wei, Yan; Chong, Xu

    2013-01-01

    For radiation protection and environmental impact assessment purpose, the radioactivity induced by carbon ion of Heavy Ion Medical Machine (HIMM) was studied. Radionuclides in accelerator component, cooling water and air at target area which are induced from primary beam and secondary particles are simulated by FLUKA Monte Carlo code. It is found that radioactivity in cooling water and air is not very important at the required beam intensity and energy which is needed for treatment, radionuclides in accelerator component may cause some problem for maintenance work, suitable cooling time is needed after the machine are shut down.

  10. Structure of light neutron-rich nuclei through Coulomb dissociation

    Indian Academy of Sciences (India)

    U Datta Pramanik; T Aumann; D Cortina; H Emling; H Geissel; M Hellström; R Holzmann; N Iwasa; Y Leifels; G Münzenberg; M Rejmund; C Scheidenberger; K Sümmerer; A Leistenschneider; Th W Elze; A Grünschloss; S Ilievski; K Boretzky; J V Kratz; R Kulessa; E Lubkiewicz; E Wajda; W Walus; P Reiter; H Simon

    2001-08-01

    Coulomb breakup of neutron-rich nuclei around mass ∼ 20 has been studied experimentally using secondary beams (∼ 500–600 MeV/u) of unstable nuclei produced at GSI. The spectroscopic factor deduced for the neutron occupying 1/2 level in 15C ground state is consistent with the earlier reported value. The data analysis for Coulomb breakup of 17C shows that most of the cross section yields the 16C core in its excited state. For 17-22O, the low-lying E1 strength amounts up to about 12% of the energy weighted dipole sum rule strength depending on neutron excess. The cluster sum rule limit with 16O as a core is almost exhausted for 17,18O, while for more neutron rich isotopes the strength with respect to that limit decreases.

  11. Halo formation in neutron rich $\\rm{Ca}$ nuclei

    CERN Document Server

    Kaushik, M; Yadav, H L

    2013-01-01

    We have investigated the halo formation in the neutron rich $\\rm{Ca}$ isotopes within the framework of recently proposed relativistic mean-field plus BCS (RMF+BCS) approach wherein the single particle continuum corresponding to the RMF is replaced by a set of discrete positive energy states for the calculation of pairing energy. For the neutron rich $\\rm{Ca}$ isotopes in the vicinity of neutron drip-line, it is found that further addition of neutrons causes a rapid increase in the neutron rms radius with a very small increase in the binding energy, indicating thereby the occurrence of halos. This is essentially caused by the gradual filling in of the loosely bound $3s_{1/2}$ state. Interesting phenomenon of accommodating several additional neutrons with almost negligible increase in binding energy is shown to be due to the pairing correlations.

  12. Octupole strength in the neutron-rich calcium isotopes

    CERN Document Server

    Riley, L A; Agiorgousis, M L; Baugher, T R; Bazin, D; Bowry, M; Cottle, P D; DeVone, F G; Gade, A; Glowacki, M T; Gregory, S D; Haldeman, E B; Kemper, K W; Lunderberg, E; Noji, S; Recchia, F; Sadler, B V; Scott, M; Weisshaar, D; Zegers, R G T

    2016-01-01

    Low-lying excited states of the neutron-rich calcium isotopes $^{48-52}$Ca have been studied via $\\gamma$-ray spectroscopy following inverse-kinematics proton scattering on a liquid hydrogen target using the GRETINA $\\gamma$-ray tracking array. The energies and strengths of the octupole states in these isotopes are remarkably constant, indicating that these states are dominated by proton excitations.

  13. Investigation of astrophysically relevant neutron-rich argon nuclei

    CERN Multimedia

    2002-01-01

    We propose to measure $\\beta$-decay properties especially the half-lives and P$_{n}$-values of the neutron-rich $^{47,48,49}$Ar nuclei. The acquired information will be important for a better understanding of the origin of the $^{48}$Ca/$^{46}$Ca isotopic "FUN" anomalies discovered in several refractory inclusions (in particular EK-1-4-1)of the Allende meteorite.

  14. Excited states of neutron rich Pd from fragmentation

    Science.gov (United States)

    Hecht, A. A.; Walters, W. B.; Hoteling, N.; Mantica, P. F.; Becerril, A.; Fleckenstein, T.; Lorusso, G.; Pereira, J.; Pinter, J.; Stoker, J.; Quinn, M.

    2007-04-01

    The neutron rich region approaching N=82 and Z=50 is interesting for nuclear structure and nuclear astrophysics, both as a test of the shell closures far from stability and as the path for r-process nucleosynthesis. This region is difficult to access with fusion-evaporation reactions and novel techniques must be used. At the National Superconducting Cyclotron Laboratory (NSCL) an experiment was recently performed by fragmentation of a Xe beam using a Be target to examine isomers and beta decay from these neutron rich nuclei. The radioisotope fragments passed through several Si planar detectors and were implanted in a double-sided Si strip detector (DSSD) in the Beta Counting System (BCS). Fragments were identified via δE and TOF. Particle emitting decays were tracked in several layers of single sided strip detectors following the DSSD, while the SEGA array surrounding the DSSD was used to collect gamma emission following beta and isomer decay. Several neutron rich nuclei were observed in this experiment, including Ru, Rh, Pd, Ag, Cd, and In. Results on Pd will be discussed.

  15. Contamination analysis of radioactive samples in focused ion beam instruments.

    Science.gov (United States)

    Evelan, Audrey Ruth; Brey, Richard R

    2013-02-01

    The use of Focused Ion Beam (FIB) instrument's to analyze and prepare samples that are radioactive requires attentiveness to the materials that are dislodged and free inside the chamber. Radioactive sputtered material must be understood even when observed at trace concentrations. Measurements using liquid scintillation counting and high purity germanium detectors were used to evaluate contamination on accessible surfaces inside a focused ion beam chamber that was used in the preparation of samples that were radioactive. The maximum removable contamination found was 0.27 0.4 Bq cm(-2), on the focused ion beam wall with 0.24 0.019 Bq cm(-2) on the door. Although these magnitudes of removable contamination are inconsequential for activation products, these same magnitudes of actinides, for example 239Pu, would represent 3.2% of an Annual Limit of Intake. This might be considered significant if one examines the relatively infrequent use of this device for the preparation of radioactive samples. Predicted activities of sputtered material were found using the software Transport of Ions in Matter, estimating that 0.003% of a radioactive samples activity is released into the FIB chamber. A used secondary electron detector's activity was measured to be 383.7 8.1 Bq. Preferential build-up of sputtered materials due to temperature or static charge gradients was considered. No temperature gradients were observed. Static charge gradients were measured inside the chamber varying between 0.057% below the mean to 34% higher than the mean. However, the magnitudes of contamination measured did not correlate to static charge gradients. Deposition in the chamber appears to have no mechanical cause but rather is sporadic however, measureable. Experience to date has been limited to samples of low activity; nevertheless, contamination inside the chamber was observed. Users should anticipate higher levels of readily dispersible radioactive contamination within the FIB as sample activity

  16. Study of resonant reactions with radioactive ion beams

    CERN Document Server

    Galindo-Uribarri, A; Chavez, E; Gomez-Del Campo, J; Gross, C J; Huerta, A; Liang, J F; Ortiz, M E; Padilla, E; Pascual, S; Paul, S D; Shapira, D; Stracener, D W; Varner, R L

    2000-01-01

    A fast and efficient method to study (p,p) and (p,alpha) resonances with radioactive beams in inverse kinematics is described. It is based on the use of thick targets and large area double-sided silicon strip detectors (DSSDs) to detect the recoiling light-charged particles and to determine precisely their scattering angle. The first nuclear physics experiments with the technique have been performed recently at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge with stable beams of sup 1 sup 7 O and radioactive beams of sup 1 sup 7 F. The high-quality resonance measurements obtained demonstrate the capabilities of the technique. Pure sup 1 sup 7 F beams from HRIBF were produced by fully stripping the ions and separating the interfering and more abundant sup 1 sup 7 O ions by the beam transport system. The removal of interfering isobars is one of the various common challenges to both accelerator mass spectrometry (AMS) and radioactive ion beam (RIB) production. Experiments done with RIBs will ben...

  17. Facilities and methods for radioactive ion beam production

    CERN Document Server

    Blumenfeld, Y; Van Duppen, P

    2013-01-01

    Radioactive ion beam facilities are transforming nuclear science by making beams of exotic nuclei with various properties available for experiments. New infrastructures and development of existing installations enlarges the scientific scope continuously. An overview of the main production, separation and beam handling methods with focus on recent developments is done, as well as a survey of existing and forthcoming facilities world-wide.

  18. Radioactive decays of highly-charged ions

    Directory of Open Access Journals (Sweden)

    Gao B. S.

    2015-01-01

    Full Text Available Access to stored and cooled highly-charged radionuclides offers unprecedented opportunities to perform high-precision investigations of their decays. Since the few-electron ions, e.g. hydrogen- or helium-like ions, are quantum mechanical systems with clear electronic ground state configurations, the decay studies of such ions are performed under well-defined conditions and allow for addressing fundamental aspects of the decay process. Presented here is a compact review of the relevant experiments conducted at the Experimental Storage Ring ESR of GSI. A particular emphasis is given to the investigations of the two-body beta decay, namely the bound-state β-decay and its time-mirrored counterpart, orbital electron-capture.

  19. Cluster structure of neutron-rich 10Be and 14C via resonant alpha scattering

    Science.gov (United States)

    Suzuki, D.; Ahn, T.; Bazin, D.; Becchetti, F. D.; Beceiro-Novo, S.; Fritsch, A.; Kolata, J. J.; Mittig, W.; AT-TPC Collaboration

    2017-09-01

    Neutron-rich ^{10} Be and ^{14} C nuclei were studied via resonant α scattering of radioactive 6 He and ^{10} Be beams, respectively, produced by the TwinSol facility at the University of Notre Dame. The Prototype Active-Target Time-Projection Chamber (pAT-TPC) was used as a thick gaseous α target to induce resonant scattering and as a device to track reacted particles inside the target, providing continuous excitation functions and angular distributions over a wide range of energies and angles. The experimental results indicate a melting phenomenon of α clusters in the 4+ rotational member of the ^{10} Be ground state and a linear chain alignment of three α clusters in ^{14} C excited states, as recently predicted by an anti-symmetrized molecular dynamics calculation.

  20. Alpha decay and cluster decay of some neutron-rich actinide nuclei

    Indian Academy of Sciences (India)

    G M CARMEL VIGILA BAI; R NITHYA AGNES

    2017-03-01

    Nuclei in the actinide region are good in exhibiting cluster radioactivity. In the present work, the half-lives of $\\alpha$-decay and heavy cluster emission from certain actinide nuclei have been calculated using cubic plus Yukawa plus exponential model ($\\bf{CYEM}$). Our model has a cubic potential for the overlapping region which is smoothly connected by a Yukawa plus exponential potential for the region after separation. The computed half-lives are compared with those of other theoretical models and are found to be in good agreement with each other. In this work, we have also studied the deformation effects on half-lives of cluster decay. These deformation effects lower the half-life values and it is also found that the neutron-rich parent nuclei slow down the cluster decay process. Geiger–Nuttal plots for various clusters are found to be linear and most of the emitted clusters are $\\alpha$-like nuclei.

  1. The prototype of radioactive ion source

    CERN Document Server

    Aleksandrov, A V; Kot, N K; Andrighetto, A; Stroe, L

    2001-01-01

    The design and experimental results of the RIB source prototype are presented.A source will have the container of sup 2 sup 3 sup 5 U compounds heated up to 2200-2500 degree C. Vapors of uranium fission obtained when the ion source is irradiated by the high-energy neutron flux, are then ionized and extracted from the source. In the experiments with the prototype loaded by sup 1 sup 2 C the source working temperature 2700 degree C was reached, the carbon ion current 10 nA was obtained. The total operation time of more than 100 hours with no performance degradation was demonstrated.

  2. Holifield Radioactive Ion Beam Facility Development and Status

    CERN Document Server

    Tatum, Alan

    2005-01-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) is a national user facility dedicated to nuclear structure, reactions, and nuclear astrophysics research with radioactive ion beams (RIBs) using the isotope separator on-line (ISOL) technique. An integrated strategic plan for physics, experimental systems, and RIB production facilities have been developed and implementation of the plan is under way. Specific research objectives are defined for studying the nature of nucleonic matter, the origin of elements, solar physics, and synthesis of heavy elements. Experimental systems upgrade plans include new detector arrays and beam lines, and expansion and upgrade of existing devices. A multifaceted facility expansion plan includes a $4.75M High Power Target Laboratory (HPTL), presently under construction, to provide a facility for testing new target materials, target geometries, ion sources, and beam preparation techniques. Additional planned upgrades include a second RIB production system (IRIS2), an external axi...

  3. New Vistas of the Structure of Neutron-Rich Nuclei - Single Particle States and g-FACTORS

    Science.gov (United States)

    Ramayya, A. V.; Hamilton, J. H.; Luo, Y. X.; Zhu, S. J.; Hwang, J. K.; Rasmussen, J. O.; Ter-Akopian, G. M.; Daniel, A. V.; Brewer, N.; Oganessian, Y.

    2012-01-01

    Prompt γ-γ-γ coincidence studies of neutron-rich nuclei populated in the spontaneous fission of 252Cf led to the discoveries of many important processes like neutron-less binary and ternary fragmentation in spontaneous fission, binary and ternary hot fission modes, hyper-deformation, cluster radioactivity and quasi-molecular states in ternary fission. The high statistics data, 5.7 × 1011 triples and higher folds, opened up discoveries of new band structures and significant extensions of previously known bands. These data were used to measure the angular correlations of cascades of γ-rays from the excited states of neutron-rich fission fragments stopped in an unmagnetized iron foil. By using this γ-γ angular correlation technique, the single particle configurations of the known rotational bands were assigned and confirmed in the present work. In other words, the multipole mixing ratios of ΔI=1 transitions in the rotational bands were measured. These experimental mixing ratios are compred with the theoretical ones of particle and axial-rotor model. The configuration of the ground states in 109,111Ru were, for the first time, assigned. And magnetic g-factors of excited states in even-even neutron-rich nuclei were meaured, too. Two sets of ΔI=1 alternating parity doublets with opposite parities were observed in Ba and Ce isotopes. The B(E1)/B(E2) branching ratios and D0 values may indicate that the octupole correlations are strong in Ba and Ce isotopes because of the Z=56 and N=88 octupole shell gaps. High-spin, even-parity bands in neutron-rich 108,110,112Ru nuclei indicate two-phonon quasi-gamma bands in 110,112Ru.

  4. Surface and Interface Studies with Radioactive Ions

    CERN Multimedia

    Weber, A

    2002-01-01

    Investigations on the atomic scale of magnetic surfaces and magnetic multilayers were performed by Perturbed Angular Correlation (PAC) spectroscopy. The unique combination of the Booster ISOLDE facility equipped with a UHV beamline and the UHV chamber ASPIC (Apparatus for Surface Physics and Interfaces at CERN) is ideally suited for such microscopic studies. Main advantages are the choice of problem-oriented radioactive probes and the purity of mass-separated beams. The following results were obtained: $\\,$i) Magnetic hyperfine fields (B$_{hf}$) of Se on Fe, Co, Ni surfaces were determined. The results prompted a theoretical study on the B$_{hf}$ values of the 4sp-elements in adatom position on Ni and Fe, confirming our results and predicting unexpected behaviour for the other elements. $\\,$ii) Exemplarily we have determined B$_{hf}$ values of $^{111}$Cd at many different adsorption sites on Ni surfaces. We found a strong dependence on the coordination number of the probes. With decreasing coordination nu...

  5. First online production of radioactive ion beams at VECC

    Energy Technology Data Exchange (ETDEWEB)

    Naik, Vaishali, E-mail: vaishali@vecc.gov.in [Variable Energy Cyclotron Centre (VECC), Sector-1 Block-AF, Bidhan Nagar, Kolkata 700064 (India); Chakrabarti, Alok; Bhattacharjee, Mahuwa; Karmakar, Prasanta [Variable Energy Cyclotron Centre (VECC), Sector-1 Block-AF, Bidhan Nagar, Kolkata 700064 (India); Bhattacharjee, Sampa [UGC-DAE CSR, Kolkata Centre, III/LB-8, Bidhan Nagar, Kolkata 700098 (India); Bandyopadhyay, Arup; Dechoudhury, Siddhartha; Kumar, Dodi Lavanya; Mondal, Manas; Pandey, H.K.; Mandi, T.K.; Dutta, D.P.; Roy, Tapatee Kundu; Bhowmik, Debasis; Sanyal, Dirtha; Ray, Ayan; Sabir Ali, Md.; Srivastava, S.C.L.; Nabhiraj, P.Y. [Variable Energy Cyclotron Centre (VECC), Sector-1 Block-AF, Bidhan Nagar, Kolkata 700064 (India)

    2013-12-15

    Highlights: • We have presented details of a gas-jet transport and catcher technique for on-line production of radioactive ion beams (RIB). • Radioactive ion beams of {sup 14}O (71 s), {sup 42}K(12.4 h), {sup 43}K (22.2 h) and {sup 41}Ar (1.8 h) have been produced using the technique. • A combined efficiency of 15–21% has been measured for diffusion through the catcher, ionization and extraction of RIB through the ECR ion-source. • Preliminary data from alpha-particle induced fission of {sup 232}Th indicates the possibility of many fission products getting transported through the gas-jet coupled ECR ion-source. -- Abstract: Radioactive ion beams (RIB) have been recently accelerated for the first time at the VECC-RIB facility. Beams of {sup 14}O (71 s), {sup 42}K (12.4 h), {sup 43}K (22 h) and {sup 41}Ar (1.8 h) have been produced by bombarding 1 atm nitrogen and argon gas targets with 1 micro-ampere proton and alpha particle beams from the K130 cyclotron. Radioactive atoms were transported 15 m away to the ECR ion-source using a gas-jet transport system. Typical measured intensity of RIB at the separator focal plane is few times 10{sup 3} pps. About 3300 pps of 1.4 MeV {sup 14}O was measured after acceleration through a 3.4 m long RFQ linac. The details of the gas-jet coupled ECR and RIB production experiments are presented.

  6. In-beam gamma-ray spectroscopy of neutron-rich nuclei using fragmentation of radioactive beams and half-lives measurements of excited levels in nuclei closed to {sup 68}Ni; Spectroscopie {gamma} en ligne de noyaux legers riches en neutrons produits par fragmentation de faisceau radioactif et mesures de temps de vie des niveaux excites dans des noyaux proches de {sup 68}Ni

    Energy Technology Data Exchange (ETDEWEB)

    Stanoiu, M.A

    2003-01-01

    This thesis deals with studies of nuclei far from the valley of stability produced at GANIL by projectile fragmentation at intermediate energies. It consists of two parts. The first one is dedicated to the study of very light exotic nuclei around N=14. This is the first time that online {gamma}-ray spectroscopy combined with the projectile fragmentation was used with radioactive incident beams at GANIL. The advantages and the limitations of this method were established. 40 different nuclei have been produced and studied at the same time. A strong dependence of the population of excited states on the type of projectile was observed. New information was obtained on the structure of the isotopes B{sup 14,15}, C{sup 17,18,19,20}, N{sup 18,19,20,21,22}, O{sup 22,23,24}, F{sup 24,25,26} and Ne{sup 29}. The level schemes obtained from this study have been compared with shell-model predictions. In particular, the energy of 1588(20) keV found for the first 2{sup +} excited state in C{sup 20}, as well as the non-existence of a bound state in O{sup 24}, show that the proton-neutron interaction plays an important role in the structure of these nuclei. In the second part, an experiment is presented concerning the neutron-rich isomer nuclei around Ni{sup 68} produced by the LISE spectrometer. The fast-timing method was applied for the first time for the study of nuclei produced by projectile fragmentation. Subnanosecond half-lives of several levels in Ni{sup 67,69,90} and Cu{sup 71,72} were measured simultaneously and with high precision. These results have allowed us to test the shell model predictions for several E2 transitions and their associated B(E2) transition probabilities. (author)

  7. Study of shape transition in the neutron-rich Os isotopes

    Directory of Open Access Journals (Sweden)

    John P.R.

    2014-03-01

    Full Text Available The neutron-rich isotopes of tungsten, osmium and platinum have different shapes in their ground states and present also shape transitions phenomena. Spectroscopic information for these nuclei is scarce and often limited to the gamma rays from the decay of isomeric states. For the neutron-rich even-even osmium isotopes 194Os and 198Os, a shape transition between a slightly prolate deformed to an oblate deformed ground state was deduced from the observed level schemes. For the even-even nucleus lying in between, 196Os, no gamma ray transition is known. In order to elucidate the shape transition and to test the nuclear models describing it, this region was investigated through gamma-ray spectroscopy using the AGATA demonstrator and the large acceptance heavy-ion spectrometer PRISMA at LNL, Italy. A two-nucleon transfer from a 198Pt target to a stable 82Se beam was utilized to populate medium-high spin states of 196Os. The analysis method and preliminary results, including the first life-time measurement of isomeric states with AGATA, are presented.

  8. Freezeouts from neutron-rich nuclear statistical equilibrium

    Science.gov (United States)

    Meyer, B. S.

    1994-07-01

    The correlated isotopic anomalies in Ca-48, Ti-50, and Cr-54 in Ca-Al rich inclusions suggest that these isotopes were coproduced in a neutron-rich Nuclear Statistical Equilibrium (NSE) environment. Nucleosynthesis theory had already reached that conclusion, largely through the NSE calculations. The astrophysical setting for this nucleosynthesis was envisioned to be near the mass cut of a type II (core-collapse) supernova. Work on supernova theory in the past several years has shown that the conditions assumed are not appropriate for the type II mass cut environment. In particular, the densities at given temperatures in the realistic supernova models are about 10x lower than those assumed for the NSE calculations. The lower density in the realistic supernova models means that more free nucleons and alpha particles are present at the time of NSE freezeout, and capture of these light particles on heavier nuclei can substantially alter the NSE abundance pattern. Do such modifications alter the NSE pattern enough to destroy the coproduction of the neutron-rich iron-group nuclei? In order to answer this question, it is necessary to make calculations with a large nucleosynthesis network. I have performed such network calculations for material expanding from an initial density of 3.4 x 107 g/cu cm and temperature 1010 K on an expansion timescale of 0.2 s. These are fairly realistic conditions in light of the supernova models. Freezeout calculations with realistic parameters confirm co-production of the neutron-rich iron-group nuclei. Further calculations are underway to explore the sensitivity of these results to the initial density and the expansion timescale.

  9. Fission decay properties of ultra neutron-rich uranium isotopes

    Indian Academy of Sciences (India)

    L Satpathy; S K Patra; R K Choudhury

    2008-01-01

    The fission decay of highly neutron-rich uranium isotopes is investigated which shows interesting new features in the barrier properties and neutron emission characteristics in the fission process. 233U and 235U are the nuclei in the actinide region in the beta stability valley which are thermally fissile and have been mainly used in reactors for power generation. The possibility of occurrence of thermally fissile members in the chain of neutron-rich uranium isotopes is examined here. The neutron number = 162 or 164 has been predicted to be magic in numerous theoretical studies carried out over the years. The series of uranium isotopes around it with = 154-172 are identified to be thermally fissile on the basis of the fission barrier and neutron separation energy systematics; a manifestation of the close shell nature of = 162 (or 164). We consider here the thermal neutron fission of a typical representative 249U nucleus in the highly neutron-rich region. Semiempirical study of fission barrier height and width shows that 250U nucleus is stable against spontaneous fission due to increase in barrier width arising out of excess neutrons. On the basis of the calculation of the probability of fragment mass yields and the microscopic study in relativistic mean field theory, this nucleus is shown to undergo exotic decay mode of thermal neutron fission (multi-fragmentation fission) whereby a number of prompt scission neutrons are expected to be simultaneously released along with the two heavy fission fragments. Such properties will have important implications in stellar evolution involving -process nucleosynthesis.

  10. Dipole response of neutron-rich Sn isotopes

    Science.gov (United States)

    Klimkiewicz, A.; Adrich, P.; Boretzky, K.; Fallot, M.; Aumann, T.; Cortina-Gil, D.; Datta Pramanik, U.; Elze, Th. W.; Emling, H.; Geissel, H.; Hellstroem, M.; Jones, K. L.; Kratz, J. V.; Kulessa, R.; Leifels, Y.; Nociforo, C.; Palit, R.; Simon, H.; Surowka, G.; Sümmerer, K.; Typel, S.; Walus, W.

    2007-05-01

    The neutron-rich isotopes 129-133Sn were studied in a Coulomb excitation experiment at about 500 AMeV using the FRS-LAND setup at GSI. From the exclusive measurement of all projectile-like particles following the excitation and decay of the projectile in a high-Z target, the energy differential cross section can be extracted. At these beam energies dipole transitions are dominating, and within the semi-classical approach the Coulomb excitation cross sections can be transformed into photoabsorption cross sections. In contrast to stable Sn nuclei, a substantial fraction of dipole strength is observed at energies below the giant dipole resonance (GDR). For 130Sn and 132Sn this strength is located in a peak-like structure around 10 MeV excitation energy and exhibits a few percent of the Thomas-Reiche Kuhn (TRK) sum-rule strength. Several calculations predict the appearance of dipole strength at low excitation energies in neutron-rich nuclei. This low-lying strength is often referred to as pygmy dipole resonance (PDR) and, in a macroscopic picture, is discussed in terms of a collective oscillation of excess neutrons versus the core nucleons. Moreover, a sharp rise is observed at the neutron separation threshold around 5 MeV for the odd isotopes. A possible contribution of 'threshold strength', which can be described within the direct-breakup model is discussed. The results for the neutron-rich Sn isotopes are confronted with results on stable nuclei investigated in experiments using real photons.

  11. Level structures of neutron-rich Xe isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Lister, C.J.; Morss, L.R. [and others

    1995-08-01

    The level structures of neutron-rich Xe isotopes were determined by observing prompt gamma-ray coincidences in {sup 248}Cm fission fragments. A 5-mg {sup 248}Cm, in the form of {sup 248}Cm-KCl pellet, was placed inside Eurogam array which consisted of 45 Compton-suppressed Ge detectors and 5 Low-Energy Photon Spectrometers. Transitions in Xe isotopes were identified by the appearance of new peaks in the {gamma}-ray spectra obtained by gating on the gamma peaks of the complementary Mo fragments.

  12. Microscopic calculations and energy expansions for neutron-rich matter

    Energy Technology Data Exchange (ETDEWEB)

    Drischler, Christian; Soma, Vittorio [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Schwenk, Achim [ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)

    2014-07-01

    We investigate the properties of asymmetric nuclear matter with two- and three-nucleon interactions based on chiral effective field theory. Focusing on neutron-rich matter, we calculate the energy for different proton fractions and include estimates of the theoretical uncertainty. We use our ab-initio results to test the quadratic expansion around symmetric matter with the symmetry energy term, and confirm its validity for highly asymmetric systems. Our calculated energy densities are in remarkable agreement with an empirical parameterization, developed to interpolate between pure neutron and symmetric nuclear matter. These findings are very useful for astrophysical applications and for developing new equations of state.

  13. New mass measurements of neutron rich nuclides at the NSCL.

    Science.gov (United States)

    Estrade, Alfredo; Matos, Milan; Amthor, Matthew; Bazin, Daniel; Becerril, Ana; Elliot, Thom; Gade, Alexandra; Galaviz, Daniel; Lorusso, Giuseppe; Pereira, Jorge; Portillo, Mauricio; Rogers, Andrew; Schatz, Hendrik; Shapira, Dan; Smith, Ed; Stolz, Andreas; Wallace, Mark

    2007-10-01

    A mass measurement of exotic isotopes in the region of 68Fe has been performed at the NSCL using the time-of-flight technique recently established. Experimental knowledge of the mass of very neutron rich nuclides is an important input for astrophysical applications, such as nucleosynthesis during the r-process and the evolution of matter in the crust of an accreting neutron star, where present calculations are mostly limited to using theoretical mass extrapolations. We present the details of the experimental set up, as well as preliminary results.

  14. Collective Band Structures in Neutron-Rich 108Mo Nucleus

    Institute of Scientific and Technical Information of China (English)

    DING Huai-Bo; WANG Jian-Guo; XU Qiang; ZHU Sheng-Jiang; J. H. Hamilton; A. V. Ramayya; J. K. Hwang; Y. X. Luo; J. O. Rasmussen; I. Y. Lee; CHE Xing-Lai

    2007-01-01

    High spin states in the neutron-rich 108Mo nucleus are studied by measuring prompt γ-rays following the spontaneous fission of 252Cf with a Gammasphere detector array. The ground-state band is confirmed, and the one-phonon γ-vibrational band is updated with spin up to 12 h. A new collective band with the band head level at 1422.4 keV is suggested as a two-phonon γ-vibrational band. Another new band is proposed as a two-quasi-proton excitation band. Systematic characteristics of the collective bands are discussed.

  15. Extended collective bands in neutron-rich 109Ru

    Institute of Scientific and Technical Information of China (English)

    DING Huai-Bo; ZHU Sheng-Jiang; J.H. Hamilton; A.V. Ramayya; J. K. Hwang; K. Li; S.H. Liu; Y.X. Luo; J.O. Rasmussen; C.T. Goodin; I. Y. Lee; WANG Jian-Guo; CHE Xing-Lai; GU Long

    2009-01-01

    Levels in the neutron-rich 109Ru have been studied by observing the prompt γ-rays following the spontaneous fission fragments of 252Cf. The ground state band and the negative parity bands have been confirmed and extended. A positive parity band with the band head level at 332.5 keV is newly identified and suggested as a single-neutron excitation band built on the 7/2+ [404] Nilsson orbital. Some structural characteristics of these bands are discussed.

  16. Charge breeding of radioactive ions with EBIS and EBIT

    CERN Document Server

    Wenander, Fredrik

    2010-01-01

    A charge state breeder, which transforms externally injected singly charged ions to a higher charge state q+, is an important tool which has applications within atomic, nuclear and even particle physics. The charge breeding concept of radioactive ions has already been demonstrated at REX-ISOLDE/CERN with the use of an Electron beam Ion Source (EBIS) and at several facilities employing Electron Resonance Cyclotron Ion Sources (ECRIS). As will be demonstrated in this paper, EBIS and Electron Beam Ion Traps (EBIT), are well suited for the task as they are capable of delivering clean, highly charged beams within a short transformation time. The increasing demand for highly charged ions of all kind of elements and isotopes, stable and radioactive, to be used for low-energy experiments such as TITAN at TRIUMF and MATS at FAIR, but also for post-acceleration to higher energies, is now pushing the development of the breeders. The next challenge will be to satisfy the needs, for example space-charge capacity, of the s...

  17. Photo-fission for the production of radioactive beams ALTO project

    CERN Document Server

    Essabaa, S; Ausset, P; Bajeat, O; Baronick, J P; Clapier, F; Coacolo, J L; Donzaud, C; Ducourtieux, M; Galas, S; Gardes, D; Grialou, D; Hosni, F; Guillemaud-Müller, D; Ibrahim, F; Junquera, T; Lau, C; Le Blanc, F; Lefort, H; Le Scornet, J C; Lesrel, J; Müller, A C; Obert, J; Perru, O; Potier, J C; Proust, J; Pougheon, F; Roussière, B; Rouvière, N; Sauvage, J; Sorlin, O; Tkatchenko, A; Verney, D; Waast, B; Rinolfi, Louis; Rossat, G; Forkel-Wirth, Doris; Müller, A; Bienvenu, G; Bourdon, J C; Garvey, Terence; Jacquemard, B; Omeich, M

    2003-01-01

    In order to probe neutron rich radioactive noble gases produced by photo-fission, a PARRNe-1 experiment (Production d'Atomes Radioactifs Riches en Neutrons) has been carried out at CERN. The incident electron beam of 50 MeV was delivered by the LIL machine: LEP Injector Linac. The experiment allowed us to compare under the same conditions two production methods of radioactive noble gases: fission induced by fast neutrons and photo-fission. The obtained results show that the use of the electrons is a promising mode to get intense neutron rich ion beams. After the success of this photo-fission experiment, a conceptual design for the installation at IPN Orsay of a 50 MeV electron accelerator close to the PARRNe-2 device has been worked out: ALTO Project. This work has started within a collaboration between IPNO, LAL (Laboratoire de l'Accelerateur Lineaire) and CERN groups.

  18. Photo-fission for the production of radioactive beams ALTO project

    Energy Technology Data Exchange (ETDEWEB)

    Essabaa, S. E-mail: essabaa@ipno.in2p3.fr; Arianer, J.; Ausset, P.; Bajeat, O.; Baronick, J.P.; Clapier, F.; Coacolo, L.; Donzaud, C.; Ducourtieux, M.; Gales, S.; Gardes, D.; Grialou, D.; Hosni, F.; Guillemaud-Mueller, D.; Ibrahim, F.; Junquera, T.; Lau, C.; Le Blanc, F.; Lefort, H.; Le Scornet, J.C.; Lesrel, J.; Mueller, A.C.; Obert, J.; Perru, O.; Potier, J.C.; Proust, J.; Pougheon, F.; Roussiere, B.; Rouviere, N.; Sauvage, J.; Sorlin, O.; Tkatchenko, A.; Verney, D.; Waast, B.; Rinolfi, L.; Rossat, G.; Forkel-Wirth, D.; Muller, A.; Bienvenu, G.; Bourdon, J.-C.; Garvey, T.; Jacquemard, B.; Omeich, M

    2003-05-01

    In order to probe neutron rich radioactive noble gases produced by photo-fission, a PARRNe-1 experiment (Production d'Atomes Radioactifs Riches en Neutrons) has been carried out at CERN. The incident electron beam of 50 MeV was delivered by the LIL machine: LEP Injector Linac. The experiment allowed us to compare under the same conditions two production methods of radioactive noble gases: fission induced by fast neutrons and photo-fission. The obtained results show that the use of the electrons is a promising mode to get intense neutron rich ion beams. After the success of this photo-fission experiment, a conceptual design for the installation at IPN Orsay of a 50 MeV electron accelerator close to the PARRNe-2 device has been worked out: ALTO Project. This work has started within a collaboration between IPNO, LAL (Laboratoire de l'Accelerateur Lineaire) and CERN groups.

  19. Progress of Target/Ion Source for Radioactive Beam

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An ISOL test bench which uses proton beam from HL-13 Tandem to generate radioactive ion beamhas been set up and primary off line test has been carried out. The effects of magnetic field, anode voltage,cathode current and flax of feed-in gas on ionization efficiency have been investigated. The results showthe overal ionization efficiency of the source is greater than 0.7%. The effort to improve the overallefficiency is still in progress.

  20. Some Key Problems Related to Radioactive Ion Beam Physics

    Institute of Scientific and Technical Information of China (English)

    叶沿林; 吕林辉

    2012-01-01

    The latest progress made in the field of radioactive ion beam physics is outlined and the key problems still under investigation are indicated. The focal points are the limit of nuclear existence, shell evolution and new magic numbers, halo and cluster structures, new excitation modes, and strong coupling between reaction channels. This field is still at a starting phase and much more new outcomes are foreseen.

  1. Techniques to produce and accelerate radioactive ion beams

    CERN Document Server

    Penescu, Liviu Constantin; Lettry, Jacques; Cata-Danil, Gheorghe

    The production and acceleration of the Radioactive Ion Beams (RIB) continues the long line of nuclear investigations started in the XIXth century by Pierre and Marie Curie, Henri Becquerel and Ernest Rutherford. The contemporary applications of the RIBs span a wide range of physics fields: nuclear and atomic physics, solid-state physics, life sciences and material science. ISOLDE is a world-leading Isotope mass-Separation On-Line (ISOL) facility hosted at CERN in Geneva for more than 40 years, offering the largest variety of radioactive ion beams with, until now, more than 1000 isotopes of more than 72 elements (with Z ranging from 2 to 88), with half-lives down to milliseconds and intensities up to 1011 ions/s. The post acceleration of the full variety of beams allows reaching final energies between 0.8 and 3.0 MeV/u. This thesis describes the development of a new series of FEBIAD (“Forced Electron Beam Induced Arc Discharge”) ion sources at CERN-ISOLDE. The VADIS (“Versatile Arc Discharge Ion Source�...

  2. Bunching and cooling of radioactive ions with REXTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, P. E-mail: k.schmidt@gsi.de; Ames, F.; Bollen, G.; Forstner, O.; Huber, G.; Oinonen, M.; Zimmer, J

    2002-04-22

    The post-accelerator REX-ISOLDE at ISOLDE/CERN will deliver radioactive ion beams with energies up to 2.2 MeV/u. For this purpose, a Penning trap and an electron-beam ion source are combined with a linear accelerator. REXTRAP - a large gas-filled Penning trap - has started its commissioning phase. First tests have shown that REXTRAP is able to accumulate, cool and bunch stable ISOLDE ion beams covering a large mass range. Fulfilling the REX-ISOLDE demands, it can handle beam intensities from a few hundred up to 1x10{sup 6} ions per pulse at repetition rates up to 50 Hz.0.

  3. Statistical properties of warm nuclei: Investigating the low-energy enhancement in the $\\gamma$- strength function of neutron-rich nuclei

    CERN Multimedia

    We propose to start a program to study the $\\gamma$-ray strength function of neutron rich nuclei in inverse kinematics with radioactive beams at HIE-ISOLDE. An unexpected increase in the $\\gamma$-strength function at low energy has been observed in several stable nuclei using the Oslo method. This year these results were confirmed with a different experimental technique and model independent analysis developed by iThemba/Livermore. If this enhancement of the $\\gamma$-strength function is also present in neutron-rich nuclei, it will strongly affect the neutron capture cross sections, which are important input in stellar models of synthesis of heavier elements in stars. We propose to start with an experiment using a $^{66}$Ni beam of 5.5 MeV /u, where the data will be analyzed using both methods independently, and we are sure to get enough statistics, before moving to more neutron-rich nuclei. When/if neutron-rich Ti, Fe or Mo beams will be available at ISOLDE, we will submit additional proposals.

  4. ISOL science at the Holifield Radioactive Ion Beam Facility

    Science.gov (United States)

    Beene, J. R.; Bardayan, D. W.; Galindo Uribarri, A.; Gross, C. J.; Jones, K. L.; Liang, J. F.; Nazarewicz, W.; Stracener, D. W.; Tatum, B. A.; Varner, R. L.

    2011-02-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) provides high-quality Isotope Separator Online beams of short-lived, radioactive nuclei for nuclear structure and reaction studies, astrophysics research, and interdisciplinary applications. The primary driver, the Oak Ridge Isochronous Cyclotron, produces rare isotopes by bombarding highly refractory targets with light ions. The radioactive isotopes are ionized, formed into a beam, mass selected, injected into the 25 MV tandem, accelerated, and used in experiments. This paper reviews the HRIBF and its users' science. Note that this manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up irrevocable, world-wide license to publish or reproduce the published form of the manuscript, or allow others to do so, for United States Government purposes.

  5. ADIGE: the radioactive ion beam injector of the SPES project

    Science.gov (United States)

    Galatà, A.; Bellan, L.; Bisoffi, G.; Comunian, M.; Martin, L.; Moisio, M. F.; Palmieri, A.; Pisent, A.; Prete, G.; Roncolato, C.

    2017-07-01

    The Selective Production of Exotic Species (SPES) project is presently under development at INFN-LNL: aim of this project is the production, ionization and postacceleration of radioactive ions to perform forefront research in nuclear physics. An ECR-based charge breeder (SPES-CB) will allow post-acceleration of radioactive ions: in particular, the SPES-CB has been designed and developed by LPSC of Grenoble, based on the Phoenix booster. It will be equipped with a complete test bench totally integrated with the SPES beam line: this part of the post-accelerator, together with the newly designed RFQ, composes the so-called ADIGE injector (Acceleratore Di Ioni a Grande carica Esotici) for the superconducting linac ALPI. The injector will employ a unique Medium Resolution Mass Spectrometer (MRMS, resolving power 1/1000), mounted downstream the SPES-CB, in order to avoid the typical drawback of the ECR-based charge breeding technique, that is the beam contamination. This contribution describes the ADIGE injector, with particular attention to the analysis of possible contaminations and the performances expected for the MRMS, showing the beam dynamics calculations for a reference radioactive beam.

  6. Half-life measurement of neutron-rich isotope 237Th

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    60 MeV/u 18O ions were used to bombard natural uranium targets, and the heavy neutron-rich isotope 237Th was produced via multi-nucleon transfer reaction and dissipative fragmentation of the heavy target. A relatively fast radiochcmical procedure was used to separate thorium from the mixture of uranium and complex reaction products. The chemically separated thorium fractions were studied by the γ-ray spectroscopic method. The behaviors of the growth and decay of 853.7 and 865.0 keV γ rays of 237pa decay were observed. Thc half-life of 237Th was determined to be 4.69±0.60 min.

  7. Identification of neutron-rich isotope 197Os

    Institute of Scientific and Technical Information of China (English)

    YANG Wei-Fan; YUAN Shuang-Gui; XU Yan-Bing; XIAO Yong-Hou; ZHAO Li-Min; WANG Ping-Zhi; LI Heng-Yuan

    2004-01-01

    A new neutron-rich isotope 197Os was produced in the 198Pt(n, 2p) reaction by irradiating natural Pt targets with 14 MeV neutrons. The γ(X) singles spectrum and coincidence spectrum measurements were performed using two HPGe γ-ray detectors. Ten unknown γ-rays at 41.2, 50.7, 196.8, 199.6, 223.9, 233.1, 250.2, 342.1,403.6, and 460.4 keV attributed to the decay of 197Os were observed in the experiments. The half-life of 197Os was found to be (2.8 ± 0.6) min. A partial decay scheme of 197Os was proposed on the basis of decay and coincidence relations. The half-life was compared with the values expected by different theoretical models.

  8. Beta decay rates of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Marketin, Tomislav, E-mail: marketin@phy.hr [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Huther, Lutz [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); Martínez-Pinedo, Gabriel [Institut für Kernphysik (Theoriezentrum), Technische Universität Darmstadt, 64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerioneneforschung, Planckstraße 1, 64291 Darmstadt (Germany)

    2015-10-15

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. Currently, a single large-scale calculation is available based on a QRPA calculation with a schematic interaction on top of the Finite Range Droplet Model. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei.

  9. Cluster emissions with ? daughter from neutron-rich nuclei

    Science.gov (United States)

    Kumar, Satish; Batra, J. S.; Gupta, Raj K.

    1996-02-01

    Cluster emissions from neutron-rich 0954-3899/22/2/006/img2, and 0954-3899/22/2/006/img3 nuclei are studied within the preformed cluster model of Malik and Gupta. Q-value estimates of the decays selected on the basis of shell effects in binding energies and their relative preformation probabilities show that these nuclei are stable (Qdecays and all the metastable (Q>0) decays are of non-alpha-like heavy clusters. The most probable decays (minimum half-life times) are the ones with a doubly magic 0954-3899/22/2/006/img6 nucleus as the daughter nucleus, arising due to the WKB penetrability. Compared to the presently measurable alpha-like cluster decays of the corresponding neutron-deficient parents into a 0954-3899/22/2/006/img7 daughter nucleus, these decays are suppressed by many orders of magnitude.

  10. Collective Bands in Neutron-Rich 104Mo Nucleus

    Institute of Scientific and Technical Information of China (English)

    杨利明; 姜卓; 全明吉; J. H. Hamilton; A. V. Ramayya; J. K. Hwang; X. Q. Zhang; B. R. S. Babu; J. Komicki; E. F. Jones; W. C. Ma; 朱胜江; J. D. Cole; R. Aryaeinejad; M. W. Drigert; I. Y. Lee; J. O. Rasmussen; M. A. Stover; G. M. Ter-Akopian; A. V. Daniel; 李科; 朱凌燕; 甘翠云; 萨哈伊; 龙桂鲁; 许瑞清; 张征

    2001-01-01

    Levels in the neutron-rich 104Mo nucleus have been investigated by observing prompt γ-rays from the spontaneous fission of 252Cf with the Gammasphere detector array. The ground-state band, the one-phonon and the twophonon γ-vibrational bands as well as a quasiparticle band have been confirmed and expanded with spin up to 14h. Other two side bands probably built on new quasiparticle states are identified. The possible configurations for the quasiparticle bands are discussed. Two of the quasiparticle bands show larger moments of inertia and may have pair-free characteristics. The levels of the ground-state band, the one-phonon γ-band and the two-phonon γ-band calculated from a general collective model are in close agreement with the experimental data.

  11. High-spin structure of neutron-rich Dy isotopes

    Indian Academy of Sciences (India)

    A Ansari; H L Yadav; M Kaushik; U R Jakhar

    2003-06-01

    In view of recent experimental progress on production and spectroscopy of neutron-rich isotopes of Dy with mass number = 166 and 168, we have made theoretical investigations on the structure of high spin states of 164-170Dy isotopes in the cranked Hartree–Fock–Bogoliubov (CHFB) theory employing a pairing+quadrupole+hexadecapole model interaction. With the increase of neutron number the rotation alignment of the proton orbitals dominates the structure at high spins, which is clearly reflected in the spin dependence of the rotational g-factors. A particularly striking feature is the difference in the spin-dependent properties of 166Dy as compared to that of 164Dy.

  12. Beta decay rates of neutron-rich nuclei

    Science.gov (United States)

    Marketin, Tomislav; Huther, Lutz; Petković, Jelena; Paar, Nils; Martínez-Pinedo, Gabriel

    2016-06-01

    Heavy element nucleosynthesis models involve various properties of thousands of nuclei in order to simulate the intricate details of the process. By necessity, as most of these nuclei cannot be studied in a controlled environment, these models must rely on the nuclear structure models for input. Of all the properties, the beta-decay half-lives are one of the most important ones due to their direct impact on the resulting abundance distributions. In this study we present the results of a large-scale calculation based on the relativistic nuclear energy density functional, where both the allowed and the first-forbidden transitions are studied in more than 5000 neutron-rich nuclei. Aside from the astrophysical applications, the results of this calculation can also be employed in the modeling of the electron and antineutrino spectra from nuclear reactors.

  13. A singly charged ion source for radioactive {sup 11}C ion acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan)

    2016-02-15

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive {sup 11}C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  14. A singly charged ion source for radioactive 11C ion acceleration

    Science.gov (United States)

    Katagiri, K.; Noda, A.; Nagatsu, K.; Nakao, M.; Hojo, S.; Muramatsu, M.; Suzuki, K.; Wakui, T.; Noda, K.

    2016-02-01

    A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

  15. Towards high-precision mass measurements of neutron-rich fission products at TRIGA-SPEC

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Szilard [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2010-07-01

    TRIGA-TRAP, the only Penning trap mass spectrometer worldwide at a nuclear research reactor, is installed at TRIGA Mainz as part of the TRIGA-SPEC experiment. The scientific goal is to perform high-precision mass measurements on lanthanoids, actinoids and neutron-rich fission products produced by thermal neutron induced fission of a target inside the reactor. High-precision mass data are scarce in this region of the nuclear chart, and further experimental data are needed for nuclear structure studies of heavy elements, to test the predictive power of nuclear mass models, or as input to nucleosynthesis calculations of the astrophysical r-process. Ions of certain lanthanoids and most actinoids as well as carbon clusters for calibration purposes can be routinely produced by a newly developed non-resonant laser ablation ion source, allowing off-line mass measurements. Besides fundamental research, TRIGA-TRAP serves as a test bench for the development of efficient ion detection techniques, which will enable mass measurements ultimately on a single ion with a half-life of the order of one second. To this end, a unique combination of the commonly used time-of-flight technique and the non-destructive image current detection method is realized in an on-line mass spectrometer. The first mass measurement results are reported.

  16. Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path

    CERN Document Server

    Rahaman, S; Eronen, T; Hager, U; Hakala, J; Jokinen, A; Kankainen, A; Karvonen, P; Moore, I D; Pentillä, H; Rinta-Antila, S; Rissanen, J; Saastamoinen, A; Sonoda, T; Äystö, J

    2007-01-01

    The Penning trap mass spectrometer JYFLTRAP, coupled to the Ion-Guide Isotope Separator On-Line (IGISOL) facility at Jyvaskyla, was employed to measure the atomic masses of neutron rich 85 to 92Br and 94 to 97Rb isotopes with a typical accuracy less than 10 keV. Discrepancies with the older data are discussed. Comparison to different mass models is presented. Details of nuclear structure, shell and subshell closures are investigated by studying the two-neutron separation energy and the shell gap energy.

  17. Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, S.; Hager, U.; Elomaa, V.V.; Eronen, T.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I.D.; Penttilae, H.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Sonoda, T.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics (YFL) (Finland)

    2007-04-15

    The Penning trap mass spectrometer JYFLTRAP, coupled to the Ion-Guide Isotope Separator On-Line (IGISOL) facility at Jyvaeskylae, was employed to measure the atomic masses of neutron-rich {sup 85-92}Br and {sup 94-97}Rb isotopes with a typical accuracy less than 10keV. Discrepancies with the older data are discussed. Comparison to different mass models is presented. Details of nuclear structure, shell and subshell closures are investigated by studying the two-neutron separation energy and the shell gap energy. (orig.)

  18. Masses of neutron-rich Ni and Cu isotopes and the shell closure at Z=28,N=40

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, S.; Hakala, J.; Elomaa, V.V.; Eronen, T.; Hager, U.; Jokinen, A.; Kankainen, A.; Moore, I.D.; Penttilae, H.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Weber, C.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35 (YFL) (Finland)

    2007-10-15

    The Penning trap mass spectrometer JYFLTRAP, coupled to the Ion Guide Isotope Separator On-Line (IGISOL) facility at Jyvaeskylae, was employed to measure the atomic masses of neutron-rich {sup 70-73}Ni and {sup 73,} {sup 75}Cu isotopes with a typical accuracy less than 5 keV. The mass of {sup 73}Ni was measured for the first time. Comparisons with the previous data are discussed. Two-neutron separation energies show a weak subshell closure at {sup 68} {sub 28}Ni{sub 40}. A well established proton shell gap is observed at Z=28. (orig.)

  19. Beta decay of neutron-rich {sup 118}Rh and the lowest excited states in {sup 118}Pd

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, A.; Wang, J.C.; Aeystoe, J.; Dendooven, P.; Nummela, S.; Huikari, J.; Kolhinen, V.; Nieminen, A.; Peraejaervi, K.; Rinta-Antila, S. [Jyvaeskylae Univ. (Finland). Dept. of Physics

    2000-09-01

    Beta decay of a refractory isotope {sup 118}Rh produced in symmetric fission and mass separated by the ion guide technique has been applied for the study of low-lying excited states of {sup 118}Pd. The yrast band in {sup 118}Pd has been observed up to a 6{sup +} state and the lowest states of the asymmetric {gamma}-band have been identified. The measured half-life of {sup 118}Rh is (300{+-}60)ms. The systematics of the excited states in neutron-rich Pd-isotopes implies the saturation towards an O(6) symmetry at N=70. (orig.)

  20. Delayed Particle Study of Neutron Rich Lithium Isotopes

    CERN Multimedia

    Marechal, F; Perrot, F

    2002-01-01

    We propose to make a systematic complete coincidence study of $\\beta$-delayed particles from the decay of neutron-rich lithium isotopes. The lithium isotopes with A=9,10,11 have proven to contain a vast information on nuclear structure and especially on the formation of halo nuclei. A mapping of the $\\beta$-strength at high energies in the daughter nucleus will make possible a detailed test of our understanding of their structure. An essential step is the comparison of $\\beta$-strength patterns in $^{11}$Li and the core nucleus $^{9}$Li, another is the full characterization of the break-up processes following the $\\beta$-decay. To enable such a measurement of the full decay process we will use a highly segmented detection system where energy and emission angles of both charged and neutral particles are detected in coincidence and with high efficiency and accuracy. We ask for a total of 30 shifts (21 shifts for $^{11}$Li, 9 shifts $^{9}$Li adding 5 shifts for setting up with stable beam) using a Ta-foil target...

  1. Transition probabilities in neutron-rich Se,8684

    Science.gov (United States)

    Litzinger, J.; Blazhev, A.; Dewald, A.; Didierjean, F.; Duchêne, G.; Fransen, C.; Lozeva, R.; Sieja, K.; Verney, D.; de Angelis, G.; Bazzacco, D.; Birkenbach, B.; Bottoni, S.; Bracco, A.; Braunroth, T.; Cederwall, B.; Corradi, L.; Crespi, F. C. L.; Désesquelles, P.; Eberth, J.; Ellinger, E.; Farnea, E.; Fioretto, E.; Gernhäuser, R.; Goasduff, A.; Görgen, A.; Gottardo, A.; Grebosz, J.; Hackstein, M.; Hess, H.; Ibrahim, F.; Jolie, J.; Jungclaus, A.; Kolos, K.; Korten, W.; Leoni, S.; Lunardi, S.; Maj, A.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatovic, T.; Million, B.; Möller, O.; Modamio, V.; Montagnoli, G.; Montanari, D.; Morales, A. I.; Napoli, D. R.; Niikura, M.; Pollarolo, G.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Sahin, E.; Salsac, M. D.; Scarlassara, F.; Söderström, P.-A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Theisen, Ch.; Valiente Dobón, J. J.; Vandone, V.; Vogt, A.

    2015-12-01

    Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich Se,8684 are investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was performed at the Istituto Nazionale di Fisica Nucleare (INFN) Laboratori Nazionali di Legnaro using the Cologne Plunger device for the RDDS technique and the AGATA Demonstrator array for the γ -ray detection coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 86Se the level lifetime of the yrast 21+ state and an upper limit for the lifetime of the 41+ state are determined for the first time. The results of 86Se are in agreement with previously reported predictions of large-scale shell-model calculations using Ni78-I and Ni78-II effective interactions. In addition, intrinsic shape parameters of lowest yrast states in 86Se are calculated. In semimagic 84Se level lifetimes of the yrast 41+ and 61+ states are determined for the first time. Large-scale shell-model calculations using effective interactions Ni78-II, JUN45, jj4b, and jj4pna are performed. The calculations describe B (E 2 ;21+→01+) and B (E 2 ;61+→41+) fairly well and point out problems in reproducing the experimental B (E 2 ;41+→21+) .

  2. Soft Dipole Modes of Neutron-Rich Nuclei

    Science.gov (United States)

    Csoto, A.; Gibson, B. F.; Afnan, I. R.

    1996-10-01

    We explore the open question of whether valance neutrons in ``halo nuclei'' can oscillate against the core to create a ``soft dipole'' mode. It has been suggested that such a dipole state would be situated at a few MeV of excitation energy, in contrast to usual dipole excitations at higher energies. The existence of a soft dipole mode, at least in ^11Li, appears to be supported by certain theoretical models and experimental data.footnote A. C. Hayes, Comments in Nuclear and Particle Physics 22, 27 (1996) However, this conclusion is based upon the behavior of specific observables at real energies. To clearly establish the existence of such resonant states, one should locate the corresponding complex poles of the S-matrix. We study ^6He and ^11Li in a three-body model based upon separable potentials that describe the known physics of the underlying two-body interactions. We solve the resulting Faddeev equations, continued into the complex energy plane, to search for the low lying excited states of these neutron-rich light nuclei.

  3. Symmetry energy of deformed neutron-rich nuclei

    CERN Document Server

    Gaidarov, M K; Sarriguren, P; de Guerra, E Moya

    2012-01-01

    The symmetry energy, the neutron pressure and the asymmetric compressibility of deformed neutron-rich even-even nuclei are calculated on the examples of Kr and Sm isotopes within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for isotopic chains of these nuclei in the framework of the self-consistent Skyrme-Hartree-Fock plus BCS method. Results for an extended chain of Pb isotopes are also presented. A remarkable difference is found in the trend followed by the different isotopic chains: the studied correlations reveal a smoother behavior in the Pb case than in the other cases. We also notice that the neutron skin thickness obtained for $^{208}$Pb with SLy4 force is found to be in a good agreement with recent data.

  4. Coulomb Excitation of a Neutron-Rich $^{88}$Kr Beam Search for Mixed Symmetry States

    CERN Multimedia

    Andreoiu, C; Napiorkowski, P J; Iwanicki, J S

    2002-01-01

    We propose to use the ISOLDE/REX/MINIBALL/CD set-up to perform a Coulomb Excitation experiment with a $^{88}$Kr radioactive beam. The motivation includes a search for $Mixed$ $Symmetry$ states predicted by the IBM-2 model, gathering more spectroscopy data about the $^{88}$Kr nucleus and extending shape coexistence studies (performed previously by the proposers for neutron-deficient Kr isotopes) to the neutron-rich side. The proposed experiment will provide data complementary to the Coulomb Excitation of a relativistic $^{88}$Kr beam proposed by D. Tonev et al. for a RISING experiment. A total of 12 days of beam time is necessary for the experiment, equally divided into two runs. One run with a 2.2 MeV/A beam energy on a $^{48}$Ti target and a second run with the maximum available REX energy of 3.1 MeV/A on a $^{208}$Pb target are requested. Using either a UC$_{x}$ or ThC$_{x}$ fissioning primary target coupled with a plasma source by a cooled transfer line seems to be the best choice for the proposed experime...

  5. TOF-B{rho} mass measurements of neutron rich nuclei at the NSCL

    Energy Technology Data Exchange (ETDEWEB)

    George, Sebastian; Galaviz, Daniel; Pereira, Jorge [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics (JINA) (United States); Estrade, Alfredo; Becerril, Ana D.; Elliot, Thom J.; Lorusso, Giuseppe; Rogers, Andrew; Schatz, Hendrik [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics (JINA) (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States); Matos, Milan [Louisiana State University, Baton Rouge, LA (United States); Amthor, Mathew A. [Grand Accelerateur National d' Ions Lourds, Bd Henri Becquerel, Caen 5 (France); Bazin, Daniel; Gade, Alexandra; Portillo, Mauricio; Stolz, Andreas [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI (United States); Shapira, Dan [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Smith, Edward [The Ohio State University, Columbus, OH (United States); Wallace, Mark S. [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2010-07-01

    Nuclear masses of exotic nuclei far from stability are important key parameters for the understanding of the nuclear structure and several questions in nuclear astrophysics. Particularly the description of astrophysical processes, such as nucleosynthesis during the r-process or the evolution of matter in the crust of accreting neutron stars, is limited by the use of theoretical mass models. The experimental access to the mass of atoms is based on different techniques. Beside the measurements of nuclear decays and nuclear reaction studies, Penning trap facilities and time-of-flight (TOF) experiments allow the determination of masses. The latter two are somewhat complementary methods in respect of precision and accessibility of exotic nuclei. The time-of-flight-B{rho} (TOF-B{rho}) method has shown the potential to access nuclides very far from stability at several radioactive beam facilities. Here the setup of the TOF-B{rho} experiment at the National Superconducting Cyclotron Laboratory (NSCL) at the Michigan State University is presented. The results of the first experiment in the region of neutron-rich isotopes as well as upcoming measurements are discussed.

  6. Evolution of single-particle strength in neutron-rich 71Cu

    Directory of Open Access Journals (Sweden)

    P. Morfouace

    2015-12-01

    Full Text Available The strength functions of the πf5/2, πp3/2 and πf7/2 orbitals in neutron-rich 71Cu were obtained in a 72Zn(d,3He71Cu proton pick-up reaction in inverse kinematics using a radioactive beam of 72Zn at 38 MeV/u. A dedicated set-up was developed to overcome the experimental challenges posed by the low cross section of the reaction and the low energy of the outgoing 3He particles. The excitation-energy spectrum was reconstructed and spectroscopic factors were obtained after analysis of the angular distributions with the finite-range Distorted-Wave Born Approximation (DWBA. The results show that unlike for the πf5/2 orbital and contrary to earlier interpretation, the πf7/2 single-particle strength distribution is not appreciably affected by the addition of neutrons beyond N=40.

  7. Enhancement of fusion at near and sub-barrier energies for neutron-rich light nuclei

    CERN Document Server

    Singh, Varinderjit; Steinbach, T K; Wiggins, B B; Hudan, S; Lin, R T deSouza Zidu; Horowitz, C J; Baby, L T; Kuvin, S A; Tripathi, Vandana; Wiedenhover, I

    2016-01-01

    Measurement of the fusion cross-section for neutron-rich light nuclei is crucial in ascertaining if fusion of these nuclei occurs in the outer crust of a neutron star. We have therefore measured the fusion excitation function at near-barrier energies for the 19O + 12C system and compared the experimental results with the fusion excitation function of 18O + 12C and 16O + 12C. In the experiment a beam of 19O, produced via the 18O(d,p) reaction, was incident on a 12C target at energies near the Coulomb barrier. Evaporation residues produced in fusion of 18,19O ions with 12C target nuclei were detected with good geometric efficiency and identified by measuring their energy and time-of-flight. A significant enhancement in the fusion probability of 19O ions with a 12C target as compared to 18O ions is observed. The significantly larger cross-sections observed at near barrier energies are not predicted by a static model of fusion for 19O + 12C indicating that dynamics play an important role in the fusion of neutron-...

  8. Radioactive Ions Production Ring for Beta-Beams

    CERN Document Server

    Benedetto, E; Wehner, J

    2010-01-01

    Within the FP7 EUROnu program, Work Package 4 addresses the issues of production and acceleration of 8Li and 8B isotopes through the Beta-Beam complex, for the production of electron-neutrino. One of the major critical issues is the production of a high enougth ion ßux, to fulÞll the requirements for physics. In alternative to the direct ISOL production method, a new ap- proach is proposed in [1]. The idea is to use a compact ring for Litium ions at 25 MeV and an internal He or D target, in which the radioactive-isotopes production takes place. The beam is expected to survive for several thousands of turns, therefore cooling in 6D is required and, according this scheme, the ionization cooling provided by the target itself and a suitable RF system would be sufÞcient. We present some preliminary work on the Production ring lat- tice design and cooling issues, for the 7Li ions, and propose plans for future studies, within the EUROnu program.

  9. Conversion electron spectroscopy of isobarically purified trapped radioactive ions

    Energy Technology Data Exchange (ETDEWEB)

    Rissanen, J.; Elomaa, V.V.; Eronen, T.; Hakala, J.; Jokinen, A.; Rahaman, S.; Rinta-Antila, S.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, P.O.B. 35 (Finland)

    2007-11-15

    The feasibility of the JYFLTRAP for in-trap spectroscopy has been studied. Several internally converted transitions have been measured for isomers of fission products with good accuracy. High-resolution spectroscopic data free of source effects have been obtained proving that trapped radioactive ions can provide excellent conversion electron sources. The shortest-lived isomer studied in this work was {sup 117m} Pd with a half-life of 19.1 ms, for which a superior peak-to-total ratio and an excellent line shape at the 9.9 keV conversion electron line have been observed. Detection efficiencies and related phenomena of the present setup are analyzed. (orig.)

  10. Radioactive ion beam development for the SPIRAL 2 project; Developpement de faisceaux d'ions radioactifs pour le projet SPIRAL 2

    Energy Technology Data Exchange (ETDEWEB)

    Pichard, A.

    2010-11-26

    This thesis focuses on the study of radioactive ion beam production by the ISOL method for the SPIRAL 2 project. The production of light ion beams is studied and the potential in-target yields of two beams are appraised. The neutron-rich {sup 15}C yield in an oxide target is estimated with simulations (MCNPx, EAF-07) and experimental data bases; the neutron-deficient {sup 14}O yield is estimated thanks to a new measurement of the {sup 12}C({sup 3}He, n){sup 14}O reaction excitation function. Based on thermal simulations, a first design of the production target is presented. This thermal study gives the necessary answers for the detailed design of the system able to reach a production yield 140 times higher than with SPIRAL 1. The production of radioactive ion beams coming from fissions in the UCx target is also studied and more particularly effusion and ionisation processes. A global study and an off-line tests campaign allow essential knowledge to the design of the surface ionisation source for SPIRAL 2 to be acquired. A first prototype of this ion source dedicated to alkali and alkaline-earth element production has been built and a thermal calibration performed. Ionisation efficiency and time response of the target-ion source system have been measured at different target temperatures and for different noble gases. These measurements allow evaluation of the impact of effusion and ionisation processes on the production efficiency of different alkali and noble gases isotopes as a function of their half-life. (author) [French] Cette these concerne l'etude de la production de faisceaux d'ions radioactifs par la methode ISOL pour le projet SPIRAL 2. La production de faisceaux legers est tout d'abord consideree. Les taux de production potentiels de deux faisceaux sont evalues: la production de {sup 15}C (riche en neutrons) dans une cible d'oxyde est estimee a l'aide de simulations (MCNPx, EAF-07) et de donnees experimentales; le taux de

  11. Measurement of picosecond lifetimes in neutron-rich Xe isotopes

    Science.gov (United States)

    Ilieva, S.; Kröll, Th.; Régis, J.-M.; Saed-Samii, N.; Blanc, A.; Bruce, A. M.; Fraile, L. M.; de France, G.; Hartig, A.-L.; Henrich, C.; Ignatov, A.; Jentschel, M.; Jolie, J.; Korten, W.; Köster, U.; Lalkovski, S.; Lozeva, R.; Mach, H.; Mǎrginean, N.; Mutti, P.; Paziy, V.; Regan, P. H.; Simpson, G. S.; Soldner, T.; Thürauf, M.; Ur, C. A.; Urban, W.; Warr, N.

    2016-09-01

    Background: Lifetimes of nuclear excited states in fission fragments have been studied in the past following isotope separation, thus giving access mainly to the fragments' daughters and only to long-lived isomeric states in the primary fragments. For the first time now, short-lived excited states in the primary fragments, produced in neutron-induced prompt fission of 235U and 241Pu, were studied within the EXILL&FATIMA campaign at the intense neutron-beam facility of the Institute Laue-Langevin in Grenoble. Purpose: We aim to investigate the quadrupole collective properties of neutron-rich even-even 138,140,142Xe isotopes lying between the double shell closure N =82 and Z =50 and a deformed region with octupole collectivity. Method: The γ rays emitted from the excited fragments were detected with a mixed array consisting of 8 HPGe EXOGAM Clover detectors (EXILL) and 16 LaBr3(Ce) fast scintillators (FATIMA). The detector system has the unique ability to select the interesting fragment making use of the high resolution of the HPGe detectors and determine subnanosecond lifetimes using the fast scintillators. For the analysis the generalized centroid difference method was used. Results: We show that quadrupole collectivity increases smoothly with increasing neutron number above the closed N =82 neutron shell. Our measurements are complemented by state-of-the-art theory calculations based on shell-model descriptions. Conclusions: The observed smooth increase in quadrupole collectivity is similar to the evolution seen in the measured masses of the xenon isotopic chain and is well reproduced by theory. This behavior is in contrast to higher Z even-even nuclei where abrupt change in deformation occurs around N =90 .

  12. Decay study of neutron-rich zirconium isotopes employing a Penning trap as a spectroscopy tool

    Energy Technology Data Exchange (ETDEWEB)

    Rinta-Antila, S.; Eronen, T.; Elomaa, V.V.; Hager, U.; Hakala, J.; Jokinen, A.; Karvonen, P.; Penttilae, H.; Rissanen, J.; Sonoda, T.; Saastamoinen, A.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics (Finland)

    2007-01-15

    A new technique to produce isobarically pure ion beams for decay spectroscopy by using a gas-filled Penning trap was commissioned at the ion guide isotope separator on-line facility, IGISOL. {beta}-decays of neutron-rich {sup 100}Zr, {sup 102}Zr and {sup 104}Zr isotopes were studied with this technique. In addition, the Q{sub {beta}{sup -}} values of {sup 100,102,104}Zr {beta}-decays were determined from the direct mass measurements of zirconium and niobium isotopes performed with a high-precision Penning trap. The mass of {sup 104}Nb was directly measured for the first time and the obtained mass excess value for the longer-living (1{sup +}) state is -71823{+-}10 keV. For the ground states of {sup 100}Nb and {sup 102}Nb the obtained mass excess values were -79802{+-}20 keV and -76309{+-}10 keV, respectively. The observed distribution of the {beta} strength supports a prolate deformation assignment for {sup 100,102,104}Zr isotopes. (orig.)

  13. Production cross sections of neutron rich isotopes from a 82Se beam

    CERN Document Server

    Tarasov, O B; Amthor, A M; Bandura, L; Baumann, T; Bazin, D; Berryman, J S; Chubarian, G; Fukuda, N; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Pereira, J; Portillo, M; Sherrill, B M; Stolz, A; Sumithrarachchi, C; Thoennessen, M; Weisshaar, D

    2012-01-01

    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements $11 \\le Z \\le 32$ were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements $22 \\le Z \\le 25$ (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.

  14. Shape coexistence in neutron-rich Sr isotopes : Coulomb excitation of 98Sr

    NARCIS (Netherlands)

    Clément, E; Görgen, A.; Korten, W.; Walle J. van de, [No Value

    2010-01-01

    In this addendum we ask for beam time to perform Coulomb excitation of 98Sr in order to complete our program on the study of shape coexistence and evolution of collectivity in neutron rich strontium isotopes at N=60.

  15. A gas jet target for radioactive ion beam experiments

    Energy Technology Data Exchange (ETDEWEB)

    Chipps, K. A.; Greife, U.; Hager, U.; Sarazin, F. [Colorado School of Mines, Golden, CO (United States); Bardayan, D. W.; Pain, S. D.; Schmitt, K. T.; Smith, M. S. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Blackmon, J. C.; Linhardt, L. E. [Louisiana State University, Baton Rouge, LA (United States); Browne, J.; Kontos, A.; Meisel, Z.; Montes, F.; Schatz, H. [National Superconducting Cyclotron Laboratory/Michigan State University, East Lansing, MI (United States); Couder, M.; Robertson, D.; Wiescher, M. [University of Notre Dame, Notre Dame, IN (United States); Erikson, L. E. [Pacific Northwest National Laboratory, Richland, WA (United States); Lemut, A. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); and others

    2013-04-19

    New radioactive ion beam (RIB) facilities, like FRIB in the US or FAIR in Europe, will push further away from stability and enable the next generation of nuclear physics experiments. Thus, the need for improved RIB targets is more crucial than ever: developments in exotic beams should coincide with developments in targets for use with those beams, in order for nuclear physics to remain on the cutting edge. Of great importance to the future of RIB physics are scattering, transfer and capture reaction measurements of rare, exotic, and unstable nuclei on light targets such as hydrogen and helium. These measurements require targets that are dense, highly localized, and pure, and conventional targets often suffer too many drawbacks to allow for such experimental designs. Targets must also accommodate the use of large area, highly-segmented silicon detector arrays, high-efficiency gamma arrays, and novel heavy ion detectors to efficiently measure the reaction products. To address this issue, the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) Collaboration led by the Colorado School of Mines (CSM) is in the process of designing, building and testing a supersonic gas jet target for use at existing and future RIB facilities. The gas jet target provides a high density and high purity of target nuclei within a tightly confined region, without the use of windows or backing materials. The design also enables the use of multiple state-of-the-art detection systems.

  16. Study of the production of neutron-rich isotope beams issuing from fissions induced by fast neutrons; Etude de la production de faisceaux riches en neutrons par fission induite par neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Ch

    2000-09-15

    This work is a contribution to the PARRNe project (production of radioactive neutron-rich isotopes). This project is based on the fission fragments coming from the fission of 238-uranium induced by fast neutrons. The fast neutron flux is produced by the collisions of deutons in a converter. Thick targets of uranium carbide and liquid uranium targets have been designed in order to allow a quick release of fission fragments. A device, able to trap on a cryogenic thimble rare gas released by the target, has allowed the production of radioactive nuclei whose half-life is about 1 second. This installation has been settled to different deuton accelerators in the framework of the European collaboration SPIRAL-2. A calibration experiment has proved the feasibility of fixing an ISOL-type isotope separator to a 15 MV tandem accelerator, this installation can provide 500 nA deutons beams whose energy is 26 MeV and be a valuable tool for studying fast-neutron induced fission. Zinc, krypton, rubidium, cadmium, iodine, xenon and cesium beams have been produced in this installation. The most intense beams reach 10000 nuclei by micro-coulomb for 26 MeV deutons. An extra gain of 2 magnitude orders can be obtained by using a more specific ion source and by increasing the thickness of the target. Another extra gain of 2 magnitude orders involves 100 MeV deutons.

  17. Extraction of radioactive positive ions across the surface of superfluid helium : A new method to produce cold radioactive nuclear beams

    NARCIS (Netherlands)

    Huang, WX; Dendooven, P; Gloos, K; Takahashi, N; Pekola, JP; Aysto, J

    2003-01-01

    Alpha-decay recoils Rn-219 were stopped in superfluid helium and positive ions were extracted by electric field into the vapour phase. This first quantitative observation of extraction was successfully conducted using highly sensitive radioactivity detection. The efficiency for extraction across the

  18. Titanate nanotubes as a promising absorbent for high effective radioactive uranium ions uptake.

    Science.gov (United States)

    Xu, Mingze; Weil, Guodong; Li, Shuang; Niu, Xiaowei; Chen, Haifeng; Zhang, He; Chubik, M; Gromov, A; Han, Wei

    2012-08-01

    In this study, titanate nanotubes with a layered structure were investigated for the uptake of radioactive uranium ions for the first time. The nanotubes have been successfully prepared with a reaction of Ti metal nanopowders and NaOH mixed solution by a novel and effective ultrasonic-assisted hydrothermal method. As the absorbent of radioactive ions, they have the ability to selectively adsorb radioactive U ions from water via ion exchange process and subsequently immobilize these ions in the nanotube sorbents without the need of further treatment after absorption. Sorption induces considerable deformation of the layer structures, resulting in the structures changing from the nanotubes to sheets and having the ability of permanent entrapment of the radioactive cations in these as-grown sheets. Our results have proved that titanate nanotubes can be used as a promising absorbent for the removal of nuclear leaking water at the first time.

  19. Interplay between collective and single particle excitations around neutron-rich doubly-magic nuclei

    Directory of Open Access Journals (Sweden)

    Leoni S.

    2016-01-01

    Full Text Available The excitation spectra of nuclei with one or two particles outside a doubly-magic core are expected to be dominated, at low energy, by the couplings between phonon excitations of the core and valence particles. A survey of the experimental situation is given for some nuclei lying in close proximity of neutron-rich doubly-magic systems, such as 47,49Ca, 133Sb and 210Bi. Data are obtained with various types of reactions (multinucleon transfer with heavy ions, cold neutron capture and neutron induced fission of 235U and 241Pu targets, with the employment of complex detection systems based on HPGe arrays. A comparison with theoretical calculations is also presented, in terms of large shell model calculations and of a phenomenological particle-phonon model. In the case of 133Sb, a new microscopic “hybrid” model is introduced: it is based on the coupling between core excitations (both collective and non-collective of the doubly-magic core and the valence nucleon, using the Skyrme effective interaction in a consistent way.

  20. Study of shape transitions in the neutron-rich Os isotopes

    Energy Technology Data Exchange (ETDEWEB)

    John, Philipp R.; Lunardi, Santo [Dipartimento di Fisica e Astronomia, Universita degli Studi di Padova, Padua (Italy); INFN Sezione di Padova, Padua (Italy); Modamio, Victor; Valiente-Dobon, Jose Javier [INFN Laboratori Nazionali di Legnaro, Legnaro (Italy); Mengoni, Daniele [Dipartimento di Fisica e Astronomia, Universita degli Studi di Padova, Padua (Italy)

    2013-07-01

    The nuclei with A ∼ 190 between Hf and Pt exhibit a great variety of nuclear phenomena, including K-isomeric states, triaxiality and shape transitions across isotopic and isotonic chains. Of particular interest is the transition from axially symmetric deformed, prolate (γ = 0 {sup circle}) to oblate (γ = 60 {sup circle}) shapes in the Os isotopic chain. While a study of the neutron-rich {sup 194}Os nucleus populated via deep-inelastic reactions suggests a prolate shape for its yrast states, an other study proposed an oblate shape for the ground state of {sup 198}Os by comparing the excitation energies of the first and second 2{sup +} states. For {sup 196}Os, the even-even isotope lying between the two, both an oblate and a prolate shape were predicted by microscopic many-body and Total Routhian Surface calculations, respectively. To further elucidate this shape transition and to refine the nuclear models, the key nucleus {sup 196}Os was investigated through gamma-spectroscopy using the AGATA demonstrator and the large acceptance heavy ion spectrometer PRISMA at LNL, Italy. A two nucleon transfer from a {sup 198}Pt target to a stable {sup 82}Se beam was utilized to populate medium-high spin states of {sup 196}Os. The current status of the analysis including preliminary results is presented.

  1. β-decay studies of the neutron-rich 18,21N isotopes

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The β-decay studies of neutron-rich 18,21N isotopes have been performed using β-n, β-γ, and β-n-γ coincidence methods. The 18,21N ions were produced by the fragmentation of the 22Ne and 26Mg beams, respectively, on a thick beryllium target. The time of flight of the emitted neutrons following the β-decay of 18,21N was measured by a neutron detector system with wide energy detection range and low-energy detection threshold. In addition, several clover germanium detectors were used to detect the β-delayed γ-rays. The half-lives of the β-decays of 18N and 21N were determined to be (619±2) ms and (82.9±7.5) ms, respec tively. Several new β-delayed neutron groups were observed with a total branching ratio of (6.98±1.46)% and (90.5±4.2)% for 18N and 21N, respectively. The level schemes of 18O and 21O were deduced. The experimental Gamow-Teller β-decay strengths of 18N and 21N to these levels were compared with the shell model calculations.

  2. Selection of RIB targets using ion implantation at the Holifield Radioactive Ion Beam Facility

    Science.gov (United States)

    Alton, G. D.; Dellwo, J.

    1996-02-01

    Among several major challenges posed by generating and accelerating adequate intensities of RIBs, selection of the most appropriate target material is perhaps the most difficult because of the requisite fast and selective thermal release of minute amounts of the short-lived product atoms from the ISOL target in the presence of bulk amounts of target material. Experimental studies are under way at the Oak Ridge National Laboratory (ORNL) which are designed to measure the time evolution of implanted elements diffused from refractory target materials which are candidates for forming radioactive ion beams (RIBs) at the Holifield Radioactive Ion Beam Facility (HRIBF). The diffusion coefficients are derived by comparing experimental data with numerical solutions to a one-dimensional form of Fick's second equation for ion implanted distributions. In this report, we describe the experimental arrangement, experimental procedures, and provide time release data and diffusion coefficients for releasing ion implanted 37Cl from Zr 5Si 3 and 75As, 79Br, and 78Se from Zr 5Ge 3 and estimates of the diffusion coefficients for 35Cl, 63Cu, 65Cu, 69Ga, and 71Ga diffused from BN; 35Cl, 63Cu, 65Cu, 69Ga, 75As, and 78Se diffused from C; 35Cl, 68Cu, 69Ga, 75As, and 78Se diffused from Ta.

  3. Penning-trap mass spectrometry of highly charged, neutron-rich Rb and Sr isotopes in the vicinity of $A\\approx100$

    CERN Document Server

    Simon, V V; Chowdhury, U; Eberhardt, B; Ettenauer, S; Gallant, A T; Mané, E; Simon, M C; Delheij, P; Pearson, M R; Audi, G; Gwinner, G; Lunney, D; Schatz, H; Dilling, J

    2012-01-01

    The neutron-rich mass region around $A\\approx100$ presents challenges for modeling the astrophysical $r$-process because of rapid shape transitions. We report on mass measurements using the TITAN Penning trap at TRIUMF-ISAC to attain more reliable theoretical predictions of $r$-process nucleosynthesis paths in this region. A new approach using highly charged ($q=15+$) ions has been applied which considerably saves measurement time and preserves accuracy. New mass measurements of neutron-rich $^{94,97,98}$Rb and $^{94,97-99}$Sr have uncertainties of less than 4 keV and show deviations of up to 11$\\sigma$ to previous measurements. An analysis using a parameterized $r$-process model is performed and shows that mass uncertainties for the A=90 abundance region are eliminated.

  4. Low-energy radioactive ion beam production of 22Mg

    Science.gov (United States)

    Duy, N. N.; Kubono, S.; Yamaguchi, H.; Kahl, D.; Wakabayashi, Y.; Teranishi, T.; Iwasa, N.; Kwon, Y. K.; Khiem, L. H.; Kim, Y. H.; Song, J. S.; Hu, J.; Ayyad, Y.

    2013-09-01

    The 22Mg nucleus plays an important role in nuclear astrophysics, specially in the 22Mg(α,p)25Al and proton capture 22Mg(p,γ)23Al reactions. It is believed that 22Mg is a waiting point in the αp-process of nucleosynthesis in novae. We proposed a direct measurement of the 22Mg+α resonance reaction in inverse kinematics using a radioactive ion (RI) beam. A 22Mg beam of 3.73 MeV/u was produced at CRIB (Center for Nuclear Study (CNS) low-energy RI Beam) facility of the University of Tokyo located at RIKEN (Japan) in 2011. In this paper we present the results about the production of the 22Mg beam used for the direct measurement of the scattering reaction 22Mg(α,α)22Mg, and the stellar reaction 22Mg(α,p)25Al in the energy region concerning an astrophysical temperature of T9=1-3 GK.

  5. Direct reaction measurements with a 132Sn radioactive ion beam

    CERN Document Server

    Jones, K L; Bardayan, D W; Blackmon, J C; Chae, K Y; Chipps, K A; Cizewski, J A; Erikson, L; Harlin, C; Hatarik, R; Kapler, R; Kozub, R L; Liang, J F; Livesay, R; Ma, Z; Moazen, B H; Nesaraja, C D; Nunes, F M; Pain, S D; Patterson, N P; Shapira, D; Shriner, J F; Smith, M S; Swan, T P; Thomas, J S

    2011-01-01

    The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of 132Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the cross section. The magnitude of the nuclear effects was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p1/2 state expected above the N=82 shell closure. The data were analyzed using finite range adiabatic wave calculations and the results compared with the previous analysis using the distorted wave Born approximation. Angular distributions for the ground and first excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sect...

  6. Single stage ECR source for the radioactive ion beam project in Louvain- la-Neuve

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M.; Vanhorenbeeck, J.; Baeten, F.; Dom, C.; Darquennes, D.; Delbar, T.; Jongen, Y.; Huyse, M.; Reusen, G.; Van Duppen, P. and others

    1989-01-01

    In 1987 the project RIB (Radioactive Ion Beam) was started at Louvain-La - Neuve, to produce and accelerate radioactive nuclei of C, N, O, F and Ne. Within the framework of this project, a single stage E.C.R. source will be built. The general scheme of the project and the design of the source are discussed.

  7. Charge Breeding of Radioactive Ions in an Electron Cyclotron Resonance Ion Source(ECRIS) at ISOLDE

    CERN Multimedia

    Lindroos, M

    2002-01-01

    The development of an efficient charge breeding scheme for the next generation of RIB facilities will have a strong impact on the post-accelerator for several Radioactive Ion Beam (RIB) projects at European large scale facilities. At ISOLDE/CERN there will be the unique possibility to carry out experiments with the two possible charge breeding set-ups with a large variety of radioactive isotopes using identical injection conditions. One charge breeding set-up is the Penning trap/EBIS combination which feeds the REX-ISOLDE linear accelerator and which is in commissioning now. The second charge breeder is a new ECRIS PHOENIX developed at the ISN ion source laboratory at Grenoble. This ECRIS is now under investigation with a 14 GHz amplifier to characterize its performance. The experiments are accompanied by theoretical studies in computer simulations in order to optimize the capture of the ions in the ECRIS plasma. A second identical PHOENIX ECRIS which is under investigation at the Daresbury Laboratory is avai...

  8. Structure and reactions of light neutron rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Esbensen, H.

    1993-01-01

    Radioactive beam experiments have made it possible to study the structure of nuclei at the neutron drip line. Pair correlations play a crucial role in such nuclei and characteristic features include an extended neutron halo density and a large dipole strength near threshold. The most detailed studies have been performed for [sup 11]Li. I will present a 3-body model that explains the main features of the data obtained for this nucleus.

  9. Structure and reactions of light neutron rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Esbensen, H.

    1993-04-01

    Radioactive beam experiments have made it possible to study the structure of nuclei at the neutron drip line. Pair correlations play a crucial role in such nuclei and characteristic features include an extended neutron halo density and a large dipole strength near threshold. The most detailed studies have been performed for {sup 11}Li. I will present a 3-body model that explains the main features of the data obtained for this nucleus.

  10. Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

    Science.gov (United States)

    Fedosseev, Valentin; Chrysalidis, Katerina; Day Goodacre, Thomas; Marsh, Bruce; Rothe, Sebastian; Seiffert, Christoph; Wendt, Klaus

    2017-08-01

    At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments. This article belongs to the Focus on

  11. Electroweak Decay Studies of Highly Charged Radioactive Ions with TITAN at TRIUMF

    CERN Document Server

    Leach, K G; Klawitter, R; Leistenschneider, E; Lennarz, A; Brunner, T; Frekers, D; Andreiou, C; Kwiatkowski, A A; Dilling, J

    2016-01-01

    Several modes of electroweak radioactive decay require an interaction between the nucleus and bound electrons within the constituent atom. Thus, the probabilities of the respective decays are not only influenced by the structure of the initial and final states in the nucleus, but can also depend strongly on the atomic charge. Conditions suitable for the partial or complete ionization of these rare isotopes occur naturally in hot, dense astrophysical environments, but can also be artificially generated in the laboratory to selectively block certain radioactive decay modes. Direct experimental studies on such scenarios are extremely difficult due to the laboratory conditions required to generate and store radioactive ions at high charge states. A new electron-beam ion trap (EBIT) decay setup with the TITAN experiment at TRIUMF has successfully demonstrated such techniques for performing spectroscopy on the radioactive decay of highly charged ions.

  12. Nuclear astrophysics and the Daresbury Recoil Separator at the Holifield Radioactive Ion Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.S.

    1997-12-01

    The Daresbury Recoil Separator (DRS) has been installed for nuclear astrophysics research at Oak Ridge National Laboratory`s Holifield Radioactive Ion Beam Facility. It will be used for direct measurements of capture reactions on radioactive ions which occur in stellar explosions such as novae, supernovae and X-ray bursts. These measurements will be made in inverse kinematics with radioactive heavy ion beams incident on hydrogen and helium targets, and the DRS will separate the capture reaction recoils from the intense flux of beam particles. Details of the new DRS experimental equipment and preliminary results from the first commissioning experiments with stable beams are described, along with the plans for the first measurements with radioactive beams. Other astrophysics research efforts at ORNL--in theoretical astrophysics, nuclear astrophysics data evaluation, heavy element nucleosynthesis, theoretical atomic astrophysics, and atomic astrophysics data--are also briefly described.

  13. Production of neutron-rich copper isotopes in 30-MeV proton-induced fission of sup 2 sup 3 sup 8 U

    CERN Document Server

    Kruglov, K; Bruyneel, B; Dean, S S; Franchoo, S; Huyse, M; Kudryavtsev, Y; Müller, W F; Prasad, N V S; Raabe, R; Reusen, I; Schmidt, K H; Van De Vel, K; Van Duppen, P; Van Roosbroeck, J; Weissman, L

    2002-01-01

    The neutron-rich isotopes sup 7 sup 0 sup - sup 7 sup 6 Cu have been produced in 30-MeV proton-induced fission of sup 2 sup 3 sup 8 U using the Ion Guide Laser Ion Source (IGLIS) at LISOL. The production rates of the copper isotopes, and of the nickel and cobalt isotopes that were measured earlier, are compared to cross section calculations. Based on these new results an estimate for the cross section of sup 7 sup 8 Ni is given.

  14. Coupled-cluster computations of unbound states in neutron rich calcium isotopes

    Science.gov (United States)

    Hagen, Gaute

    2014-09-01

    In this talk I will present microscopic coupled-cluster computations of weakly bound and unbound states in the neutron rich calcium region. Starting from state-of-the-art nucleon-nucleon and schematic three-nucleon forces, the role of continuum on ordering of states close to and above the threshold is discussed. In particular several new level orderings are predicted that contrast the naïve shell-model ordering of states. We also discuss the possibility for Efimov physics around the very neutron rich calcium-62 by merging input from coupled-cluster calculations with halo effective-field-theory.

  15. Beta Decay Half-lives and Delayed Neutron Emission of r-process Neutron-Rich nuclei in the vicinity of 78Ni

    Science.gov (United States)

    Madurga, M.

    2012-10-01

    The region of neutron rich isotopes at and beyond the N=50 shell closure in the vicinity of ^78Ni has recently attracted major interest from experimental and theoretical nuclear physics community [1-4]. Moreover, as many nuclei in the region are predicted precursors of r-process nucleosynthesis, their most basic nuclear properties such as mass and beta decay half-life are required parameters in abundance calculations. The availability of hight purity and high quality radioactive beams of nuclei in this region at the Holifield Radioactive Ion Beam Facility has spurred a systematic campaign to study their properties through beta decay. Four new half-lives of ^82,83Zn, ^85Ga and ^86Ge were measured for the first time. The resulting values differ from the predictions of the Finite Range Droplet Model used in r-process abundance calculations. We presented a new model based on Density Functional Theory that correctly reproduced the new half-lives. The revised analysis of the rapid neutron capture process in low entropy environments with our new set of measured and calculated half-lives shows a significant redistribution of predicted isobaric abundances strengthening the yield of A > 140 nuclei. Continuing our effort to systematically understand decay properties in the region of beta-delayed neutron emission, 30 nuclei in the region were studied using the neutron energy Time-of-Flight detector VANDLE. Due to the shell structure in the region, most of the decay strength is expected to concentrate in states above neutron separation energy, in the so-called Pigmy Giant resonance. Precise knowledge of the position and strength of the resonance may help fine tune and develop existing models, with the aim of increasing their reliability beyond what can be experimentally measured. The data resulting from the experimental campaign at Holifield are still being analyzed. In a few species strong shell effects have already been identified and they will be presented. In particular

  16. Are there good probes for the di-neutron correlation in light neutron-rich nuclei?

    CERN Document Server

    Hagino, K

    2015-01-01

    The di-neutron correlation is a spatial correlation with which two valence neutrons are located at a similar position inside a nucleus. We discuss possible experimental probes for the di-neutron correlation. This includes the Coulomb breakup and the pair transfer reactions of neutron-rich nuclei, and the direct two-neutron decays of nuclei beyond the neutron drip-line.

  17. New Isomers in the Neutron-Rich Region Beyond 208Pb

    Directory of Open Access Journals (Sweden)

    Gottardo A.

    2014-03-01

    Full Text Available The region of neutron-rich nuclei beyond 208Pb has been very difficult to explore due to its high mass and exoticity. However, recent experimental improvements allowed one to perform a quite extended isomer decay spectroscopy of these nuclei.

  18. Evidence for a Smooth Onset of Deformation in the Neutron-Rich Kr Isotopes

    NARCIS (Netherlands)

    Albers, M.; Warr, N.; Nomura, K.; Blazhev, A.; Jolie, J.; Muecher, D.; Bastin, B.; Bauer, C.; Bernards, C.; Bettermann, L.; Bildstein, V.; Butterworth, J.; Cappellazzo, M.; Cederkaell, J.; Cline, D.; Darby, I.; Das Gupta, S.; Daugas, J. M.; Davinson, T.; De Witte, H.; Diriken, J.; Filipescu, D.; Fiori, E.; Fransen, C.; Gaffney, L. P.; Georgiev, G.; Gernhaeuser, R.; Hackstein, M.; Heinze, S.; Hess, H.; Huyse, M.; Jenkins, D.; Konki, J.; Kowalczyk, M.; Kroell, T.; Kruecken, R.; Litzinger, J.; Lutter, R.; Marginean, N.; Mihai, C.; Moschner, K.; Napiorkowski, P.; Singh, B. S. Nara; Nowak, K.; Otsuka, T.; Pakarinen, J.; Pfeiffer, M.; Radeck, D.; Reiter, P.; Rigby, S.; Robledo, L. M.; Rodriguez-Guzman, R.; Rudigier, M.; Sarriguren, P.; Scheck, M.; Seidlitz, M.; Siebeck, B.; Simpson, G.; Thoele, P.; Thomas, T.; Van de Walle, J.; Van Duppen, P.; Vermeulen, M.; Voulot, D.; Wadsworth, R.; Wenander, F.; Wimmer, K.; Zell, K. O.; Zielinska, M.

    2012-01-01

    The neutron-rich nuclei Kr-94,Kr-96 were studied via projectile Coulomb excitation at the REX-ISOLDE facility at CERN. Level energies of the first excited 2(+) states and their absolute E2 transition strengths to the ground state are determined and discussed in the context of the E(2(1)(+)) and

  19. -decay measurements for N > 40 Mn nuclei and inference of collectivity for neutron-rich Fe isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Daugas, J [CEA, DAM, DIF, Arpajon cedex, France; Delaroche, J. P. [CEA, DAM, DIF, Arpajon cedex, France; Pfutzner, M. [University of Warsaw; Sawicka, M. [University of Warsaw; Becker, F. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Belier, G. [CEA, DAM, DIF, Arpajon cedex, France; Bingham, C. R. [University of Tennessee, Knoxville (UTK); Borcea, C. [IFIN, Bucharest-Magurele, Romania; Bouchez, E. [CEA, Cetre de Sacaly, Gif-sur-Yvette, France; Buta, A. [IFIN, Bucharest-Magurele, Romania; Dragulescu, E. [IFIN, Bucharest-Magurele, Romania; Georgiev, G. [Grand Accelerateur National d' Ions Lourds (GANIL); Giovinazzo, J. [CEN Bordeaux-Gradignan/CNRS, France; Girod, M. [CEA, DAM, DIF, Arpajon cedex, France; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Grzywacz, R. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Hammache, F. [CNRS/IN2P3, Orsay, France; Ibrahim, F. [CNRS/IN2P3, Orsay, France; Lewitowicz, M. [Grand Accelerateur National d' Ions Lourds (GANIL); Libert, J. [CNRS/IN2P3, Orsay, France; Mayet, P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Meot, V. [CEA, DAM, DIF, Arpajon cedex, France; Negoita, F. [IFIN, Bucharest-Magurele, Romania; de Oliveira Santos, F. [Grand Accelerateur National d' Ions Lourds (GANIL); Perru, O. [CEA, DAM, DIF, Arpajon cedex, France; Roig, O. [CEA, DAM, DIF, Arpajon cedex, France; Rykaczewski, Krzysztof Piotr [ORNL; Saint-Laurent, M. G. [Grand Accelerateur National d' Ions Lourds (GANIL); Sauvestre, J. E. [CEA, France; Sorlin, O. [Grand Accelerateur National d' Ions Lourds (GANIL); Stanoiu, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Stefan, I. [CNRS/IN2P3, Orsay, France; Stodel, Ch. [Grand Accelerateur National d' Ions Lourds (GANIL); Theisen, Ch. [LSCE/CEA, Gif-sur-Yvette, France; Verney, D. [CNRS/IN2P3, Orsay, France; Zylicz, J. [University of Warsaw

    2011-01-01

    A decay spectroscopic study of the neutron-rich isotopes has been performed using fragmentation of a 86Kr primary beam. Fragments from this reaction have been selected by the LISE2000 spectrometer at the Grand Acc el erateur National d Ions Lourds (GANIL). Half-lives of 29 isotopes, including the first ones identified for 61Ti (15 4 ms), 64V (19 8 ms), and 71Fe (28 5 ms), have been determined and compared with model predictions. 67,68Mn -delayed rays were observed for the first time. The branching for the -delayed neutron emission was measured to be greater than 10(5)% in the 67Mn decay. The 67Fe isomeric level is firmly determined at higher energy than assigned in previous works. The excitation energies of the first (2+) and (4+) states of 68Fe are suggested to lie at 522(1) and 1389(1) keV, respectively, thus bringing confirmation of assignments based on in-beam -ray spectroscopy. Beyond-mean-field calculations with the Gogny D1S force have been performed for even-mass nuclei through the Fe isotopic chain. Not only 68Fe but most of the neutron-rich Fe isotopes with neutron numbers below N = 50 are interpreted as soft rotors. The calculated mean occupancy of the neutron g9/2 and d5/2 orbitals in correlated ground states is steadily growing with increasing neutron number throughout the isotopic chain. Interpretation of 67Fe data is based upon the present calculations for the 66Fe and 68Fe even cores.

  20. Alkali suppression for pure Radioactive Ion Beam (RIB) production

    CERN Document Server

    E. Bouquerel, R. Catherall, M. Eller, J. Lettry, S. Marzari, T. Stora and the ISOLDE

    The ISOLDE facility at CERN has constantly developed new ion beams with betterpurity and improved yields over the last decades. Chemical selectivity for the productionof pure RIBs can be achieved by condensation of less volatile species in the transferline between the target and the ion source and by selective ionisation schemes such asthat provided by Resonance Ionization Laser Ion Source (RILIS)...

  1. Coupling a CLOVER detector array with the PRISMA magnetic spectrometer. Investigation of moderately neutron-rich nuclei populated by multinucleon transfer and deep inelastic collisions

    Energy Technology Data Exchange (ETDEWEB)

    Gadea, A.; Napoli, D.R.; Angelis, G. de; Stefanini, A.M.; Corradi, L.; Axiotis, M.; Berti, L.; Fioretto, E.; Kroell, T.; Latina, A.; Marginean, N.; Maron, G.; Martinez, T.; Rosso, D.; Rusu, C.; Toniolo, N.; Szilner, S.; Trotta, M. [Laboratori Nazionali di Legnaro Padova (Italy); Menegazzo, R.; Bazzacco, D. [Dipartimento di Fisica, Universita di Padova (Italy); INFN, Sezione di Padova (Italy); Beghini, S.; Bellato, M.; Brandolini, F.; Farnea, E.; Isocrate, R.; Lenzi, S.M.; Lunardi, S.; Montagnoli, G.; Pavan, P.; Rossi Alvarez, C.; Scarlassara, F.; Ur, C.; Blasi, N.; Bracco, A.; Camera, F.; Leoni, S.; Million, B.; Pignanelli, M.; Pollarolo, G.; DeRosa, A.; Inglima, G.; La Commara, M.; La Rana, G.; Pierroutsakou, D.; Romoli, M.; Sandoli, M.; Bizzeti, P.G.; Bizzeti-Sona, A.M.; Lo Bianco, G.; Petrache, C.M.; Zucchiatti, A.; Cocconi, P.; Quintana, B.; Beck, C.; Curien, D.; Duchene, G.; Haas, F.; Medina, P.; Papka, P.; Durell, J.; Freeman, S.J.; Smith, A.; Varley, B.; Fayz, K.; Pucknell, V.; Simpson, J.; Gelletly, W.; Regan, P.

    2004-04-01

    Following the commissioning of the PRISMA large-acceptance spectrometer, installed at the Laboratori Nazionali di Legnaro (LNL), an international nuclear-structure collaboration has started to develop a large {gamma}-ray setup to be installed in the target position of the spectrometer. The array is based on the EUROBALL composite CLOVER detectors. In this contribution the CLOVER detector array is described and its expected performance figures discussed. This new setup, by using the high-intensity heavy-ion beams provided by the LNL ALPI linac, will push the study of nuclear structure towards moderately neutron-rich nuclei by means of quasi-elastic and deep inelastic reactions. (orig.)

  2. New heavy neutron-rich isotope 238Th

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A new nuclide 238Th has been produced via multinucleon transferreaction by 60 MeV/u 18O ion irradiation of the natural uranium.The thorium wasradiochemically separated from the mixture of uranium and reaction products.Theactivity of thorium was measured by using an HPGe detector and a planar HPGedetector. The 238Th has been identified for the first time by measuringthe growth and decay of the γ-rays from its daughter 238Pa. Thehalf-life of 238Th was determined tobe 9.4±2.0 min. In addition, a new γ-ray of 89.0±0.3 keVwith T1/2=8.9±1.5 min wasfound in the γ spectrum gated with X-rays of Pa and assigned to238Th β- decay basedon measurements of transition energy and half life.

  3. A cheap and compact mass spectrometer for radioactive ions based on a Wien filter

    Science.gov (United States)

    Pierret, C.; Maunoury, L.; Pacquet, J. Y.; Saint-Laurent, M.-G.; Tuske, O.

    2008-10-01

    This paper presents simulations of a mass spectrometer composed of one or two Wien filters. The ion source used is MONO1000 ECRIS. This ion source can produce singly charged ions with high efficiency, especially for gaseous materials. After extraction, the ions are mass selected and can be injected either into a beam line towards an experiment area or in an N+ charge booster. Due to its compactness and simplicity the proposed spectrometer is well adapted for preparing and analyzing radioactive beams. The simulations are based on the SIMION 3D [www.simion.com/] software.

  4. A cheap and compact mass spectrometer for radioactive ions based on a Wien filter

    Energy Technology Data Exchange (ETDEWEB)

    Pierret, C. [CIRIL, CEA/DSM CNRS/IN2P3, Avenue Henri Becquerel, B.P. 5133, F-14070 Caen cedex 05 (France)], E-mail: Pierret@ganil.fr; Maunoury, L. [CIRIL, CEA/DSM CNRS/IN2P3, Avenue Henri Becquerel, B.P. 5133, F-14070 Caen cedex 05 (France); Pacquet, J.Y.; Saint-Laurent, M.-G. [GANIL, CEA/DSM CNRS/IN2P3, Boulevard Henri Becquerel, B.P. 55027, F-14076 Caen cedex 05 (France); Tuske, O. [CEA/Saclay, DSM/DAPNIA, 91191 Gif/Yvette (France)

    2008-10-15

    This paper presents simulations of a mass spectrometer composed of one or two Wien filters. The ion source used is MONO1000 ECRIS. This ion source can produce singly charged ions with high efficiency, especially for gaseous materials. After extraction, the ions are mass selected and can be injected either into a beam line towards an experiment area or in an N{sup +} charge booster. Due to its compactness and simplicity the proposed spectrometer is well adapted for preparing and analyzing radioactive beams. The simulations are based on the SIMION 3D [ (http://www.simion.com/)] software.

  5. Laser photodetachment of radioactive ions: towards the determination of the electronegativity of astatine

    CERN Multimedia

    Rothe, Sebastian; Welander, Jakob Emanuel; Chrysalidis, Katerina; Day Goodacre, Thomas; Fedosseev, Valentine; Fiotakis, Spyridon; Forstner, Oliver; Heinke, Reinhard Matthias; Johnston, Karl; Kron, Tobias; Koester, Ulli; Liu, Yuan; Marsh, Bruce; Ringvall Moberg, Annie; Rossel, Ralf Erik; Seiffert, Christoph; Studer, Dominik; Wendt, Klaus; Hanstorp, Dag

    2017-01-01

    Negatively charged ions are mainly stabilized through the electron correlation effect. A measure of the stability of a negative ion is the electron affinity, which the energy gain by attaching an electron to a neutral atom. This fundamental quantity is, due to the almost general lack of bound excited states, the only atomic property that can be determined with high accuracy for negative ions. We will present the results of the first laser photodetachment studies of radioactive negative ions at CERN-ISOLDE. The photodetachment threshold for the radiogenic iodine isotope 128I was measured successfully, demonstrating the performance of the upgraded GANDALPH experimental beam line. The first detection of photo-detached astatine atoms marks a milestone towards the determination of the EA of this radioactive element.

  6. MODELING AN ION EXCHANGE PROCESS FOR CESIUM REMOVAL FROM ALKALINE RADIOACTIVE WASTE SOLUTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Smith, F; Luther Hamm, L; Sebastian Aleman, S; Johnston Michael, J

    2008-08-26

    The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for the removal of cesium from alkaline radioactive waste solutions has been investigated through computer modeling. Cesium adsorption isotherms were obtained by fitting experimental data using a thermodynamic framework. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study also tested the sensitivity of ion-exchange column performance to variations in flow rate, temperature and column dimensions. Modeling results can be used to optimize design of the ion exchange system.

  7. Fusion at the barrier with light radioactive ion beams

    CERN Document Server

    Signorini, C

    2001-01-01

    The experimental results recently obtained for fusion reactions at energies close to the Coulomb barrier with light radioactive (loosely bound) beams are reviewed and critically discussed. There have been two conflicting views on the effect of the loose binding of the projectile on the fusion cross section. On the one hand one expects an enhancement of the fusion cross section due to the loose binding while, on the other hand, the easy breakup of the projectile is expected to inhibit the fusion cross section. We critically discuss these two aspects of loose binding by comparing the experimental results for a number of radioactive beams. The data for sup 1 sup 7 F (where the last neutron binding energy S sub n =0.601 MeV), neither show breakup effects nor enhancement when compared with the fusion of the nucleus sup 1 sup 9 F. The data for a sup 6 He beam (S sub 2 sub n =0.975 MeV) show enhancement, very strong in one case, and the strong breakup (BU)+transfer cross section may be related to this. The fusion da...

  8. Two alpha, three alpha and multiple heavy-ion radioactivities

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M. (Institute for Physics and Nuclear Engineering, Bucharest (Romania))

    1985-07-01

    New decay modes by spontaneous emission of two and three ..cap alpha.. particles and two identical or different heavy ions, are predicted. The analytical variant of the superasymmetric fission model is used to estimate the half lives.

  9. Two alpha, three alpha and multiple heavy-ion radioactivities

    OpenAIRE

    Poenaru, D.N.; Ivascu, M.

    1985-01-01

    New decay modes by spontaneous emission of two and three α particles and two identical or different heavy ions, are predicted. The analytical variant of the superasymmetric fission model is used to estimate the half lives.

  10. Neutron-rich 104,106,108Mo Isotopes in the Generalized Collective Model

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Generalized Collective Model (GCM) is applied to the even-even neutron-rich 104,106,108Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy Surfaces (PES) for the 104,106,108Mo isotopes are calculated. The PES of all these isotopes show a prolate minimum which becomes more pronounced in 106Mo. The results are in agreement with the recent experimental report but are different from the viewpoint of the triaxial rotors, or γ-soft deformation. Through a systematic study of PES, it is suggested that the even-even neutron-rich 104,106,108Mo isotopes have prolate deformation.

  11. TOF-Bρ Mass Measurement of Neutron Rich Nuclei at the NSCL

    Science.gov (United States)

    Estradé, Alfredo; Matoš, Milan; Amthor, Matthew A.; Bazin, Daniel; Becerril, Ana D.; Elliot, Thom J.; Gade, Alexandra; Galaviz, Daniel; Lorusso, Giuseppe; Pereira, Jorge; Portillo, Mauricio; Rogers, Andrew; Schatz, Hendrik; Shapira, Dan; Smith, Edward; Stolz, Andreas; Wallace, Mark S.

    2007-10-01

    Experimental knowledge of nuclear masses of exotic nuclei is important for understanding nuclear structure far from the valley of β-stability, and as a direct input into astrophysical models. In the case of astrophysical processes involving neutron rich nuclei, such as nucleosynthesis during the r-process and the evolution of matter in the crust of an accreting neutron star, we are mostly limited to using theoretical mass models. The time of flight (TOF) mass measurement technique allows measuring very short-lived nuclei. It has been effectively applied using the fast fragment beams produced at the A1900 fragment separator at the National Superconducting Cyclotron Lab (NSCL) to reach masses very far from stability. We describe a recent mass measurement experiment in the neutron rich Fe region performed at the NSCL, and present preliminary results.

  12. Symmetry energy effects on isovector properties of neutron rich nuclei with a density functional approach

    CERN Document Server

    Papazoglou, M C

    2014-01-01

    We employ a variational method to study the effect of the symmetry energy on the neutron skin thickness and the symmetry energy coefficients of various neutron rich nuclei. We concentrate our interest on $^{208}$Pb, $^{124}$Sn, $^{90}$Zr, and $^{48}$Ca, although the method can be applied in the totality of medium and heavy neutron rich nuclei. Our approach has the advantage that the isospin asymmetry function $\\alpha(r)$, which is the key quantity to calculate isovector properties of various nuclei, is directly related with the symmetry energy as a consequence of the variational principle. Moreover, the Coulomb interaction is included in a self-consistent way and its effects can be separated easily from the nucleon-nucleon interaction. We confirm, both qualitatively and quantitatively, the strong dependence of the symmetry energy on the various isovector properties for the relevant nuclei, using possible constraints between the slope and the value of the symmetry energy at the saturation density.

  13. Study of neutron-rich Mo isotopes by the projected shell model approach

    Indian Academy of Sciences (India)

    Gopal Krishan; Rawan Kumar; Rani Devi; S K Khosa

    2014-09-01

    The projected shell model (PSM) calculations have been performed for the neutron-rich even–even 102−110Mo and odd–even 103−109Mo isotopes. The present calculation reproduces the available experimental data on the yrast bands. In case of even–even nuclei, the structure of yrast bands is analysed and electromagnetic quantities are compared with the available experimental data. The -factors have been predicted for high spin states. For the odd-neutron nuclei, the structures of yrast positive- and negative-parity bands are analysed and found to be in reasonable agreement with the experiments for 103−107Mo. The disagreement of the calculated and observed plots for energy staggering quantity clearly establishes the occurrence of sizable triaxiality in 103,105Mo and also predicts a decrease in the quantum of triaxiality with increasing neutron number and angular momentum for odd mass neutron-rich Mo isotopes.

  14. Dipole response in neutron-rich nuclei with new Skyrme interactions

    CERN Document Server

    Zheng, H; Colonna, M; Baran, V

    2016-01-01

    We investigate the isoscalar and isovector E1 response of neutron-rich nuclei, within a semi-classical transport model employing effective interactions for the nuclear mean-field. In particular, we adopt the recently introduced SAMi-J Skyrme interactions, whose parameters are specifically tuned to improve the description of spin-isospin properties of nuclei. Our analysis evidences a relevant degree of isoscalar/isovector mixing of the collective excitations developing in neutron-rich systems. Focusing on the low-lying strength emerging in the isovector response, we show that this energy region essentially corresponds to the excitation of isoscalar-like modes, which also contribute to the isovector response owing to their mixed character. Considering effective interactions which mostly differ in the isovector channels, we observe that these mixing effects increase with the slope L of the symmetry energy at saturation density, leading to a larger strength in the low-energy region of the isovector response. This...

  15. Study of neutron-rich nuclei using deep-inelastic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, I.Y.; Asztalos, S.; Deleplanque, M.; Cederwall, B.; Diamond, R.M.; Fallon, P.; Macchiavelli, A.O.; Phair, L.; Stephens, F.S.; Wozniak, G.J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Frauendorf, S.G. [Research Center Rossendorf, Dresden (Germany); Becker, J.A.; Henry, E.A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hua, P.F.; Sarantites, D.G. [Washington University, St. Louis, Missouri 63130 (United States); Saladin, J.X. [University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Yu, C.H. [University of Rochester, Rochester, New York 14627 (United States)

    1997-08-01

    We have used the {sup 48}Ca+{sup 176}Yb reaction to study the population of high-spin states in neutron-rich nuclei by deep-inelastic reactions. Using Gammasphere, we observed gamma transitions from nuclei several neutrons richer than the target. Yrast states with spin up to 20 were populated in this reaction. High-spin states in {sup 175,177,178}Yb were observed. In this region of reduced pairing, a reference based on experimental data was used to derive experimental Routhians. Systematics of experimental Routhians in neutron-rich Yb nuclei compare well with cranked shell-model calculations. {copyright} {ital 1997} {ital The American Physical Society}

  16. Spin yields of neutron-rich nuclei from deep inelastic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Asztalos, S.J.; Lee, I.Y.; Vetter, K.; Cederwall, B.; Clark, R.M.; Deleplanque, M.A.; Diamond, R.M.; Fallon, P.; Jing, K.; Phair, L.; Macchiavelli, A.O.; Rasmussen, J.O.; Stephens, F.S.; Wozniak, G.J. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Becker, J.A.; Bernstein, L.A.; McNabb, D.P. [Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hua, P.F.; Sarantites, D.G. [Washington University, St. Louis, Missouri 63130 (United States); Saladin, J.X. [University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Yu, C. [University of Rochester, Rochester, New York 14627 (United States); Cizewski, J.A. [Rutgers University, New Brunswick, New Jersey 08903 (United States); Donangelo, R. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janiero (Brazil)

    1999-10-01

    The potential for using deep inelastic reactions to populate high-spin states in neutron-rich nuclei is studied in a series of experiments using GAMMASPHERE for {gamma}-ray detection and a silicon strip detector for measuring the angles of projectilelike and targetlike fragments. In three experiments 61 new transitions up to a maximum spin of 22{h_bar} in 12 neutron-rich rare-earth nuclei were found. We observe that {gamma}-ray yields as a function of spin are flatter for all neutron transfer products than for inelastic excitation of either the projectile or target nucleus. Calculations are presented which indicate that this difference cannot be accounted for by quasielastic processes, but more likely are the result of larger energy loss processes, such as deep inelastic reactions. {copyright} {ital 1999} {ital The American Physical Society}

  17. Observation of Large Enhancement of Charge Exchange Cross Sections with Neutron-Rich Carbon Isotopes

    CERN Document Server

    Tanihata, I; Kanungo, R; Ameil, F; Atkinson, J; Ayyad, Y; Cortina-Gil, D; Dillmann, I; Estradé, A; Evdokimov, A; Farinon, F; Geissel, H; Guastalla, G; Janik, R; Knoebel, R; Kurcewicz, J; Litvinov, Yu A; Marta, M; Mostazo, M; Mukha, I; Nociforo, C; Ong, H J; Pietri, S; Prochazka, A; Scheidenberger, C; Sitar, B; Strmen, P; Takechi, M; Tanaka, J; Toki, H; Vargas, J; Winfield, J S; Weick, H

    2015-01-01

    Production cross sections of nitrogen isotopes from high-energy carbon isotopes on hydrogen and carbon targets have been measured for the first time for a wide range of isotopes. The fragment separator FRS at GSI was used to deliver C isotope beams. The cross sections of the production of N isotopes were determined by charge measurements of forward going fragments. The cross sections show a rapid increase with the number of neutrons in the projectile. Since the production of nitrogen is mostly due to charge exchange reactions below the proton separation energies, the present data suggests a concentration of Gamow-Teller and Fermi transition strength at low excitation energies for neutron-rich isotopes. It was also observed that the cross sections were enhanced much more strongly for neutron rich isotopes in the C-target data.

  18. New μs isomers in the neutron-rich {sup 210}Hg nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Gottardo, A., E-mail: andrea.gottardo@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, 35020 (Italy); Dipartimento di Fisica dell' Università degli Studi di Padova, Padova, 35131 (Italy); Valiente-Dobón, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, 35020 (Italy); Benzoni, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, 20133 (Italy); Gadea, A. [Instituto de Física Corpuscular, CSIC-Universitat de València, València, E-46980 (Spain); Lunardi, S. [Dipartimento di Fisica dell' Università degli Studi di Padova, Padova, 35131 (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova, 35131 (Italy); Boutachkov, P. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Bruce, A.M. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton, BN2 4GJ (United Kingdom); Górska, M. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Grebosz, J. [Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Krakow, PL-31-342 (Poland); Pietri, S. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Podolyák, Zs. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Pfützner, M. [Faculty of Physics, University of Warsaw, Warsaw, PL-00681 (Poland); Regan, P.H. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Weick, H. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Alcántara Núñez, J. [Universidade de Santiago de Compostela, Santiago de Compostela, E-175706 (Spain); and others

    2013-10-01

    Neutron-rich nuclei in the lead region, beyond N=126, have been studied at the FRS-RISING setup at GSI, exploiting the fragmentation of a primary uranium beam. Two isomeric states have been identified in {sup 210}Hg: the 8{sup +} isomer expected from the seniority scheme in the νg{sub 9/2} shell and a second one at low spin and low excitation energy. The decay strength of the 8{sup +} isomer confirms the need of effective three-body forces in the case of neutron-rich lead isotopes. The other unexpected low-lying isomer has been tentatively assigned as a 3{sup −} state, although this is in contrast with theoretical expectations.

  19. Neutron-rich isotope production using a uranium carbide - carbon nanotubes SPES target prototype

    Science.gov (United States)

    Corradetti, S.; Biasetto, L.; Manzolaro, M.; Scarpa, D.; Carturan, S.; Andrighetto, A.; Prete, G.; Vasquez, J.; Zanonato, P.; Colombo, P.; Jost, C. U.; Stracener, D. W.

    2013-05-01

    The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

  20. The Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, J.D. [Oak Ridge National Lab., TN (United States)

    1996-12-31

    The status of the new Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory (ORNL), which is slated to start its scientific program late this year is discussed, as is the new experimental equipment which is being constructed at this facility. Information on the early scientific program also is given.

  1. Progress Report of Beijing Radioactive Ion-Beam Facility (BRIF) in 2011

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The year 2011 is featured with several important events for the Beijing Radioactive Ion-beam Facility (BRIF) project. At the beginning of the year, the two divisions of the BRIF project, i.e. Engineering Division and Technology Division, have been merged into one as the BRIF Division.

  2. Progress Report of Beijing Radioactive Ion-Beam Facility (BRIF) in 2012

    Institute of Scientific and Technical Information of China (English)

    YI; Hui; SUN; Yang

    2012-01-01

    <正>The year 2012 is featured with several important events for the Beijing Radioactive Ion-beam Facility (BRIF) project. With joint efforts from all sides, the team has made significant progress in the construction, the main equipment manufacturing, installation and assembly throughout the year.

  3. Progress Report of Beijing Radioactive Ion-beam Facility(BRIF)

    Institute of Scientific and Technical Information of China (English)

    YI; Hui; SUN; Yang

    2015-01-01

    In 2015,the Beijing Radioactive Ion-beam Facility(BRIF)project made progress under efforts of all employees.The significant progress was made in the construction,the main process equipment installation,shakedown test and successful completion of the task for the whole year.

  4. Excitation of pygmy dipole resonance in neutron-rich nuclei via Coulomb and nuclear fields

    Indian Academy of Sciences (India)

    A Vitturi; E G Lanza; M V Andrés; F Catara; D Gambacurta

    2010-07-01

    We study the nature of the low-lying dipole strength in neutron-rich nuclei, often associated with the pygmy dipole resonance. The states are described within the Hartree–Fock plus RPA formalism, using different parametrizations of the Skyrme inter-action. We show how the information from combined reaction processes involving the Coulomb and different mixtures of isoscalar and isovector nuclear interactions can provide a clue to reveal the characteristic features of these states.

  5. Temperature dependence of a spreading width of giant dipole resonance in neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Vdovin, A.I.; Storozhenko, A.N

    2003-07-14

    A temperature dependence of the spreading width of a giant dipole resonance is studied in the framework of the Quasiparticle-Phonon Model extended to finite temperature using a formalism of the Thermo Field Dynamics. Numerical calculations are performed for {sup 120}Sn and the neutron-rich double-magic isotope {sup 132}Sn It is found that the dispersion of the E1 strength function {sigma} increases with temperature.

  6. High-spin level structure of the neutron-rich nucleus 91Y

    CERN Document Server

    He, Xiao-Feng; Fang, Yong-De; Liu, Min-Liang; Zhang, Yu-Hu; Wang, Kai-Long; Wang, Jian-Guo; Guo, Song; Qiang, Yun-Hua; Zheng, Yong; Zhang, Ning-Tao; Li, Guang-Shun; Gao, Bing-Shui; Wu, Xiao-Guang; He, Chuang-Ye; Zheng, Yun

    2015-01-01

    High-spin level structure of the neutron-rich nucleus 91Y has been reinvestigated via the 82Se(13C, p3n)91Y reaction. A newly constructed level scheme including several key levels clarifies the uncertainties in the earlier studies. These levels are characterized by the breaking of the Z=38 and N=56 subshell closures, which involves in the spin-isospin dependent central force and tensor force.

  7. Identification of a $9/2^-$[505] isomer in the neutron-rich $^{193}$Os nucleus

    OpenAIRE

    Gao, B. S.; Zhou, X. H.; Fang, Y. D.; Zhang, Y.H.; Liu, M.L.; Wang, S C; Wang, J.G.; F. Ma; Guo, Y. X.; Wu, X. G.; He, C.Y.(China Institute of Atomic Energy, Beijing, 102413, China); Zheng, Y.; Wang, Z. M.; Yan, X. L.; Wang, Z.G.

    2013-01-01

    The neutron rich nucleus $^{193}$Os was produced in the $^{192}$Os($^{7}$Li,$^{6}$Li)$^{193}$Os reaction. An isomeric state based on the $9/2^-$[505] nilsson orbital was identified in the present work. Half-life of the isomeric state was extracted and discussed in terms of the $K$ quantum number. Level scheme built on the isomeric state was proposed based on the experimental data.

  8. Probing Matter Radii of Neutron-Rich Nuclei by Antiproton Scattering

    OpenAIRE

    Lenske, H.; P. Kienle

    2005-01-01

    We propose to use antiprotons to investigate the sizes of stable and neutron-rich exotic nuclei by measurements of the $\\pbar A$ absorption cross section along isotopic chains in inverse kinematics. The expected effects are studied theoretically in a microscopic model. The $\\pbar U$ optical potentials are obtained by folding free space $\\pbar N$ scattering amplitudes with HFB ground state densities and solving the scattering equations by direct integration. The mass dependence of absorption c...

  9. Enhanced collectivity of gamma vibration in neutron-rich Dy isotopes with N=108 - 110

    CERN Document Server

    Yoshida, Kenichi

    2016-01-01

    Background: The $\\gamma$ vibrational mode of excitation is an acknowledged collective mode in deformed nuclei. The collectivity depends on the details of the shell structure around the Fermi levels, in particular the presence of the orbitals that have the enhanced transition matrix elements of the non-axial quadrupole excitation. Quite recently, a sudden decrease in the excitation energy of the $\\gamma$ vibration was observed at RIKEN RIBF for the neutron-rich Dy isotopes at $N=106$. Purpose: In the present work, by studying systematically the microscopic structure of the $\\gamma$ vibration in the neutron-rich Dy isotopes with $N=98-114$, we try to understand the mechanism of the observed softening. Methods: The low-frequency modes of excitation in the neutron-rich rare-earth nuclei are described based on nuclear density-functional theory. We employ the Skyrme energy-density functionals (EDF) in the Hartree-Fock-Bogoliubov calculation for the ground states and in the Quasiparticle Random-Phase Approximation (...

  10. GALS – setup for production and study of heavy neutron rich nuclei

    CERN Document Server

    Zemlyanoy, Sergey; Kozulin, Eduard; Kudryavtsev, Yury; Fedosseev, Valentin; Bark, Robert; Janas, Zenon; Othman, Hosam

    2015-01-01

    The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 below ^208Pb is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion-fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of ^136Xe with ^208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126.

  11. GALS – setup for production and study of heavy neutron rich nuclei

    Directory of Open Access Journals (Sweden)

    Zemlyanoy Sergey

    2015-01-01

    Full Text Available The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 below 208Pb is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion–fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of 136Xe with 208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126.

  12. Measuring Neutrino Mass with Radioactive Ions in a Storage Ring

    Science.gov (United States)

    Lindroos, Mats; McElrath, Bob; Orme, Christopher; Schwetz, Thomas

    2010-03-01

    A method to measure the neutrino mass kinematically using beams of ions which undergo beta decay is proposed. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. By counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for mν<0.2 eV, it is necessary to control the ion momentum with a precision better than δp/p<10-5, identify suitable nuclei with low Q-values (in the few to ten keV range), and one must be able to observe at least O(1018) decays.

  13. Measuring neutrino mass with radioactive ions in a storage ring

    CERN Document Server

    Lindroos, Mats; Orme, Christopher; Schwetz, Thomas

    2009-01-01

    We propose a method to measure the neutrino mass kinematically using beams of ions which undergo beta decay. The idea is to tune the ion beam momentum so that in most decays, the electron is forward moving with respect to the beam, and only in decays near the endpoint is the electron moving backwards. Then, by counting the backward moving electrons one can observe the effect of neutrino mass on the beta spectrum close to the endpoint. In order to reach sensitivities for $m_\

  14. Radioactive core ions of microclusters, ``snowballs`` in superfluid helium

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, N. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Shimoda, T. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Fujita, Y. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Miyatake, H. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Mizoi, Y. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Kobayashi, H. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Sasaki, M. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Shirakura, T. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Itahashi, T. [Research Center for Nuclear Physics, Osaka Univ., Ibaraki (Japan); Mitsuoka, S. [Research Center for Nuclear Physics, Osaka Univ., Ibaraki (Japan); Matsukawa, T. [Naruto Univ. of Education, Tokushima (Japan); Ikeda, N. [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Morinobu, S. [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Hinde, D.J. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences; Asahi, K. [Tokyo Inst. of Tech. (Japan). Dept. of Physics; Ueno, H. [Tokyo Inst. of Tech. (Japan). Dept. of Physics; Izumi, H. [Tokyo Inst. of Tech. (Japan). Dept. of Physics

    1996-12-01

    Short-lived beta-ray emitters, {sup 12}B, sustaining nuclear spin polarization were introduced into superfluid helium. The nuclear polarization of {sup 12}B was observed via measurement of beta-ray asymmetry. It was found that the nuclear polarization was preserved throughout the lifetime of {sup 12}B (20.3 ms). This suggests that the ``snowball``, an aggregation of helium atoms produced around an alien ion, constitutes a suitable milieu for freezing-out the nuclear spin of the core ion and that most likely the solidification takes place at the interior of the aggregation. (orig.).

  15. 94 β -Decay Half-Lives of Neutron-Rich Cs 55 to Ho 67 : Experimental Feedback and Evaluation of the r -Process Rare-Earth Peak Formation

    Science.gov (United States)

    Wu, J.; Nishimura, S.; Lorusso, G.; Möller, P.; Ideguchi, E.; Regan, P.-H.; Simpson, G. S.; Söderström, P.-A.; Walker, P. M.; Watanabe, H.; Xu, Z. Y.; Baba, H.; Browne, F.; Daido, R.; Doornenbal, P.; Fang, Y. F.; Gey, G.; Isobe, T.; Lee, P. S.; Liu, J. J.; Li, Z.; Korkulu, Z.; Patel, Z.; Phong, V.; Rice, S.; Sakurai, H.; Sinclair, L.; Sumikama, T.; Tanaka, M.; Yagi, A.; Ye, Y. L.; Yokoyama, R.; Zhang, G. X.; Alharbi, T.; Aoi, N.; Bello Garrote, F. L.; Benzoni, G.; Bruce, A. M.; Carroll, R. J.; Chae, K. Y.; Dombradi, Z.; Estrade, A.; Gottardo, A.; Griffin, C. J.; Kanaoka, H.; Kojouharov, I.; Kondev, F. G.; Kubono, S.; Kurz, N.; Kuti, I.; Lalkovski, S.; Lane, G. J.; Lee, E. J.; Lokotko, T.; Lotay, G.; Moon, C.-B.; Nishibata, H.; Nishizuka, I.; Nita, C. R.; Odahara, A.; Podolyák, Zs.; Roberts, O. J.; Schaffner, H.; Shand, C.; Taprogge, J.; Terashima, S.; Vajta, Z.; Yoshida, S.

    2017-02-01

    The β -decay half-lives of 94 neutron-rich nuclei Cs-151144 , Ba-154146 , La-156148 , Ce-158150 , Pr-160153 , Nd-162156 , Pm-163159 , Sm-166160 , Eu-168161 , Gd-170165 , Tb-172166 , Dy-173169 , Ho-175172 , and two isomeric states Erm174 , Dym172 were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β -decay half-lives are observed at neutron-number N =97 for Ce 58 , Pr 59 , Nd 60 , and Sm 62 , and N =105 for Eu 63 , Gd 64 , Tb 65 , and Dy 66 . Features in the data mirror the interplay between pairing effects and microscopic structure. r -process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.

  16. On the retention of uranyl and thorium ions from radioactive solution on peat moss.

    Science.gov (United States)

    Humelnicu, Doina; Bulgariu, Laura; Macoveanu, Matei

    2010-02-15

    The efficiency of the radioactive uranyl and thorium ions on the peat moss from aqueous solutions has been investigated under different experimental conditions. The sorption and desorption of uranyl and thorium ions on three types (unmodified peat moss, peat moss treated with HNO(3) and peat moss treated with NaOH) of peat moss were studied by the static method. Peat moss was selected as it is available in nature, in any amount, as a cheap and accessible sorbent. Study on desorption of such ions led to the conclusion that the most favourable desorptive reagent for the uranyl ions is Na(2)CO(3) 1M while, for the thorium ions is HCl 1M. The results obtained show that the parameters here under investigation exercise a significant effect on the sorption process of the two ions. Also, the investigations performed recommend the peat moss treated with a base as a potential sorbent for the uranyl and thorium ions from a radioactive aqueous solution.

  17. Recent radioactive ion beam program at RIKEN and related topics

    Indian Academy of Sciences (India)

    Akira Ozawa

    2001-08-01

    Recent experimental programs at RIKEN concerning RI beams are reviewed. RIKEN has the ring cyclotron (RRC) with high intense heavy-ion beams and large acceptance fragment separator, RIPS. The complex can provide high intense RI-beams. By using the high intense RI-beams, a variety of experiments have been done. Recently, nuclear structure for unstable nuclei has been paid much attention. In special, disappearance and appearance of magic numbers are discussed experimentally and theoretically. Thus, in this review, related experiments concerning disappearance and appearance of magic numbers are described. Finally, future project in RIKEN, RI-beam factory, is introduced briefly.

  18. Physics and Technology for the Next Generation of Radioactive Ion Beam Facilities: EURISOL

    CERN Document Server

    Kadi, Y; Catherall, R; Giles, T; Stora, T; Wenander, F K

    2012-01-01

    Since the discovery of artificial radioactivity in 1935, nuclear scientists have developed tools to study nuclei far from stability. A major breakthrough came in the eighties when the first high energy radioactive beams were produced at Berkeley, leading to the discovery of neutron halos. The field of nuclear structure received a new impetus, and the major accelerator facilities worldwide rivalled in ingenuity to produce more intense, purer and higher resolution rare isotope beams, leading to our much improved knowledge and understanding of the general evolution of nuclear properties throughout the nuclear chart. However, today, further progress is hampered by the weak beam intensities of current installations which correlate with the difficulty to reach the confines of nuclear binding where new phenomena are predicted, and where the r-process path for nuclear synthesis is expected to be located. The advancement of Radioactive Ion Beam (RIB) science calls for the development of so-called next-generation facil...

  19. IRACM : A code system to calculate induced radioactivity produced by ions and neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Susumu; Fukuda, Mitsuhiro; Nishimura, Koichi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Watanabe, Hiromasa; Yamano, Naoki

    1997-05-01

    It is essential to estimate of radioactivity induced in accelerator components and samples bombarded by energetic ion beams and the secondary neutrons of high-energy accelerator facilities in order to reduce the amount of radioactive wastes and to minimize radiation exposure to personnel. A computer code system IRACM has been developed to estimate product nuclides and induced radioactivity in various radiation environments of accelerator facilities. Nuclide transmutation with incident particles of neutron, proton, deuteron, alpha, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne and {sup 40}Ar can be computed for arbitrary multi-layer target system in a one-dimensional geometry. The code system consists of calculation modules and libraries including activation cross sections, decay data and photon emission data. The system can be executed in both FACOM-M780 mainframe and DEC workstations. (author)

  20. Radioactive ion beams for biomedical research and nuclear medical application

    CERN Document Server

    Beyer, Gerd-Jürgen

    2002-01-01

    The ISOLDE facility at CERN is the world leading on On-Line Isotope Separator installation. The main aspects which makes ISOLDE produced radio-isotopes such valuable for use in biomedical research are: the availability of exotic or uncommon radioisotopes, the high purity and the ion beam quality. A short overview on research strategies, on experimental work and application of ISOLDE produced radionuclides used in the field of biomedicine over a period of more than 2 decades will be given. Special attention will be directed to the radio- lanthanides, because they can be seen as one single element providing the unique possibility to study systematically relationships between molecule parameters and a biological response without changes in the basic tracer molecule. Among those radionuclides we find any radiation properties we wish (single photon emission) suitable for SPECT, positron emission suitable for positron emission tomography (PET), alpha -, beta /sup -/- and Auger electron emission. (21 refs).

  1. Neutron-rich rare-isotope production from projectile fission of heavy nuclei near 20 MeV/nucleon beam energy

    Science.gov (United States)

    Vonta, N.; Souliotis, G. A.; Loveland, W.; Kwon, Y. K.; Tshoo, K.; Jeong, S. C.; Veselsky, M.; Bonasera, A.; Botvina, A.

    2016-12-01

    We investigate the possibilities of producing neutron-rich nuclides in projectile fission of heavy beams in the energy range of 20 MeV/nucleon expected from low-energy facilities. We report our efforts to theoretically describe the reaction mechanism of projectile fission following a multinucleon transfer collision at this energy range. Our calculations are mainly based on a two-step approach: The dynamical stage of the collision is described with either the phenomenological deep-inelastic transfer model (DIT) or with the microscopic constrained molecular dynamics model (CoMD). The de-excitation or fission of the hot heavy projectile fragments is performed with the statistical multifragmentation model (SMM). We compared our model calculations with our previous experimental projectile-fission data of 238U (20 MeV/nucleon) + 208Pb and 197Au (20 MeV/nucleon) + 197Au and found an overall reasonable agreement. Our study suggests that projectile fission following peripheral heavy-ion collisions at this energy range offers an effective route to access very neutron-rich rare isotopes toward and beyond the astrophysical r-process path.

  2. Measurement of ground state properties of neutron-rich nuclei on the r-process path between the N=50 and N=82 shells

    CERN Multimedia

    2007-01-01

    The evolution of the unknown ground-state ${\\beta}$-decay properties of the neutron-rich $^{84-89}$Ge, $^{90-93}$Se and $^{102-104}$Sr isotopes near the r-process path is of high interest for the study of the abundance peaks around the N=50 and N=82 neutron shells. At ISOLDE, beams of certain elements with sufficient isotopic purity are produced as molecular sidebands rather than atomic beams. This applies e.g, to germanium, separated as GeS$^{+}$, selenium separated as SeCO$^{+}$ and strontium separated as SrF$^{+}$. However, in case of neutron-rich isotopes produced in actinide targets, new "isobaric" background of atomic ions appears on the mass of the molecular sideband. For this particular case, the ECR charge breeder, positioned in the experimental hall after ISOLDE first mass separation, can be advantageously used as a purification device, by breaking the molecules and removing the molecular contaminants. This proposal indicates our interest in the study of basic nuclear structure properties of neutron...

  3. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    CERN Document Server

    Fraser, M A; Jones, R M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering...

  4. Development of treatment process by pyrolysis of low level radioactive spent ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Nagahara, Satoshi; Kidoguchi, Akira; Ushikoshi, Juntaro; Kanda, Nobuyasu [Mitsui Shipbuilding and Engineering Co. Ltd., Tokyo (Japan)

    2001-03-01

    Mitsui Engineering and Shipbuilding Co., Ltd. has been successfully developing a continuous treatment process by pyrolysis under reduction condition for low level radioactive ion-exchange resin used in nuclear power plants, for the purpose of reducing its volume with excellent decontamination performance. Pyrolysis experiments with labo-scale and bench-scale test equipments were carried out, followed by the continuous pyrolysis treatment test in the full-scale test equipment with feed rate at 7 liter/hour which was composed of a rotary kiln pyrolysis drum and an after-burner. Results showed an excellent performance of pyrolysis for the treatment of the spent resin. The properties of cement immobilization of residue sufficiently meet the governmental regulations, and we are confident that the continuous treatment process of the disposal for the low level radioactive ion-exchange resin used in nuclear power plants is established. (author)

  5. Radioactive beams produced by the ISOL method: development for laser ionization and for surface ionization; Faisceaux exotiques par methode ISOL: developpements pour l'ionisation par laser et l'ionisation de surface

    Energy Technology Data Exchange (ETDEWEB)

    Hosni, Faouzi

    2004-10-01

    The works were carried out in the framework of the research program PARRNe (production of radioactive neutron-rich nuclei). This program aims to determine optimal conditions to produce intense beams of neutron-rich isotopes. This thesis treats multiple technical aspects related to the production of separate radioactive isotopes in line (ISOL). It deals mainly with the development of the target-source unit which is the key element for projects such as SPIRAL-2 or EURISOL.The first part presents the various methods using fission as production mode and compares them: fission induced by thermal neutrons, induced by fast neutrons and photofission. The experiment carried out at CERN validated the interest of the photofission as a promising production mode of radioactive ions. That is why the institute of nuclear physics of Orsay decided to build a linear electron accelerator at the Tandem d'Orsay (ALTO).The second part of this thesis deals with the development of uranium targets. The X-rays diffraction and Scanning Electron Microscopy have been used as analysis techniques. They allowed to determine the chemical and structural characteristics of uranium carbide targets as function of various heating temperatures. After the production, the process of ionization has been studied. Two types of ion source have been worked out: the first one is a surface ion source and the second one is a source based on resonant ionization by laser. These two types of sources will be used for the ALTO project. (author)

  6. The radioactive ion beam project at VECC, Kolkata – A status report

    Indian Academy of Sciences (India)

    Alok Chakrabarti

    2002-12-01

    A project to build an ISOL-post accelerator type of radioactive ion beam (RIB) facility has been undertaken at VECC, Kolkata. The funding for the first phase of the project was approved in August 1997. This phase will be the R&D phase and will be completed by December 2003. The present status of development of the various sub-systems of the RIB facility will be discussed.

  7. Progress Report of Beijing Radioactive Ion-beam Facility(BRIF) in 2013

    Institute of Scientific and Technical Information of China (English)

    YI; Hui; SUN; Yang

    2013-01-01

    The year of 2013 is featured with several important events for the Beijing Radioactive Ion-beam Facility(BRIF)project.In this year,the BRIF has made a significant progress in the construction,the main equipment installation,shakedown test and successful completion of the task of the whole year.1 Four units acceptance of building engineering,public engineering equipment installation completed and put into use

  8. Decay spectroscopy of neutron-rich rare-earth isotopes and collectivity around double midshell

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Hiroshi, E-mail: hiroshi@ribf.riken.jp [IRCNPC, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2015-10-15

    Neutron-rich rare-earth isotopes with A ≈ 170, which locate near the middle of the major shells for both proton and neutron between the doubly magic nuclei {sup 132}Sn and {sup 208}Pb, have been investigated by means of decay spectroscopy techniques at the RIBF facility at RIKEN. The nuclei of interest were produced by in-flight fission of a high-intensity {sup 238}U beam at 345 MeV/u. In this contribution, scientific motivations, the details of experimental procedures, and some prospects of the data analysis are reported.

  9. Study of neutron-rich $^{51−53}$ Ca isotopes via $\\beta$-decay

    CERN Multimedia

    The high Q$_\\beta$ values in certain neutron-rich regions of the chart of nuclides opens up the possibility to study states in the daughter nuclei which lie at high excitation energy, above the neutron separation threshold. We propose to perform spectroscopy of the $\\beta$-delayed neutron emission of the $^{51-53}$K isotopes to study the population of single-particle or particle-hole states both below and above the neutron separation threshold. The VANDLE neutron detector will be used in combination with the IDS tape station setup and Ge detectors.

  10. Coulomb excitation of neutron-rich $^{134-136}$Sn isotopes

    CERN Multimedia

    We propose to study excited states in the isotopes $^{134,136}$Sn by $\\gamma$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to investigate the evolution of quadrupole collectivity beyond the magic shell closure at N = 82 by the determination of B(E2) values and electric quadrupole moments $\\mathcal{Q}_2$. Recent shell-model calculations using realistic interactions predict possible enhanced collectivity in neutron-rich regions. Evidence for this could be obtained by this experiment. Furthermore, the currently unknown excitation energies of the 2$^+_{1}$ and 4$^+_{1}$ states in $^{136}$Sn will be measured for the first time.

  11. Application of the generator coordinate method to neutron-rich Se and Ge isotopes

    Science.gov (United States)

    Higashiyama, Koji; Yoshinaga, Naotaka

    2014-03-01

    The quantum-number projected generator coordinate method (GCM) is applied to the neutron-rich Se and Ge isotopes, where the monopole and quadrupole pairing plus quadrupole-quadrupole interaction is employed as an effective interaction. The energy spectra obtained by the GCM are compared to both the shell model results and the experimental data. The GCM reproduces well the energy levels of high-spin states as well as the low-lying states. The structure of the low-lying collective states is analyzed through the GCM wave functions.

  12. Application of the generator coordinate method to neutron-rich Se and Ge isotopes

    Directory of Open Access Journals (Sweden)

    Higashiyama Koji

    2014-03-01

    Full Text Available The quantum-number projected generator coordinate method (GCM is applied to the neutron-rich Se and Ge isotopes, where the monopole and quadrupole pairing plus quadrupole-quadrupole interaction is employed as an effective interaction. The energy spectra obtained by the GCM are compared to both the shell model results and the experimental data. The GCM reproduces well the energy levels of high-spin states as well as the low-lying states. The structure of the low-lying collective states is analyzed through the GCM wave functions.

  13. Continuum quasiparticle random phase approximation for astrophysical direct neutron capture reaction of neutron-rich nuclei

    OpenAIRE

    Matsuo, Masayuki

    2014-01-01

    We formulate a many-body theory to calculate the cross section of direct radiative neutron capture reaction by means of the Hartree-Fock-Bogoliubov mean-field model and the continuum quasiparticle random phase approximation (QRPA). A focus is put on very neutron-rich nuclei and low-energy neutron kinetic energy in the range of O(1 keV) - O(1 MeV), relevant for the rapid neutron-capture process of nucleosynthesis. We begin with the photo-absorption cross section and the E1 strength function, t...

  14. Search for Double γ-Vibrational Bands in Neutron-Rich 105Mo Nucleus

    Institute of Scientific and Technical Information of China (English)

    DING Huai-Bo; CHEN Yong-Jing; LI Ming-Liang; ZHU Sheng-Jiang; J. H. Hamilton; A. V. Ramayya; J. K. Hwang; Y. X. Luo; J. O. Rasmussen; I. Y. Lee; CHE Xing-Lai

    2006-01-01

    Levels in the neutron-rich 105 Mo nucleus have been investigated by observing prompt γ-rays following the spon taneous fission fragments of 252 Cf with the Gammasphere detector array. The yrast band has been confirmed and updated. The other two collective bands with the band head levels at 870.5 and 1534.6 keV are newly observed,and they are suggested as the candidates for one-phonon K = 9/2 and two-phonon K = 13/2 double γ-vibrational bands, respectively. Systematic characteristics of these bands have been discussed.

  15. Prompt γ-ray spectroscopy of the neutron-rich 124Cd

    Directory of Open Access Journals (Sweden)

    Vancraeyenest A.

    2013-12-01

    Full Text Available Prompt γ-ray spectroscopy of neutron-rich cadmium isotopes has been performed. The nuclei of interest have been populated via a 25-MeV, proton-induced fission of the 238U thick target and prompt γ-rays measured using the multi-detector HPGe array JUROGAM II. New high-spin decays have been observed and placed in the level scheme using triple coincidence gates. The experimental results are compared to shell-model calculations and show good agreement.

  16. First measurement of beta decay half-lives in neutron-rich Tl and Bi isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Benzoni, G., E-mail: giovanna.benzoni@mi.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Morales, A.I. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Valiente-Dobon, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy); Gottardo, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro (Italy); Dipartimento di Fisica dell' Universita degli Studi di Padova, Padova (Italy); Bracco, A.; Camera, F.; Crespi, F.C.L.; Corsi, A.M.; Leoni, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Dipartimento di Fisica dell' Universita degli Studi di Milano, Milano (Italy); Million, B. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Nicolini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Dipartimento di Fisica dell' Universita degli Studi di Milano, Milano (Italy); Wieland, O. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Gadea, A. [Instituto de Fisica Corpuscular, CSIC-Universitat de Valencia, Valencia (Spain); Lunardi, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova (Italy); Dipartimento di Fisica dell' Universita degli Studi di Padova, Padova (Italy); Boutachkov, P. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Bruce, A.M. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton (United Kingdom); Gorska, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Grebosz, J. [Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Krakow (Poland); and others

    2012-09-10

    Neutron-rich isotopes around lead, beyond N=126, have been studied exploiting the fragmentation of an uranium primary beam at the FRS-RISING setup at GSI. For the first time {beta}-decay half-lives of {sup 219}Bi and {sup 211,212,213}Tl isotopes have been derived. The half-lives have been extracted using a numerical simulation developed for experiments in high-background conditions. Comparison with state of the art models used in r-process calculations is given, showing a systematic underestimation of the experimental values, at variance from close-lying nuclei.

  17. Experimental investigations on the nuclear structure of the neutron-rich nuclides 44S and 20O

    Science.gov (United States)

    Santiago-Gonzalez, Daniel

    Experimental results of two independent studies on the nuclear structure of the neutron-rich nuclei S4416 and O20 8 O are presented. A short introduction on the context of these studies within nuclear physics is given in chapter 1. Because of the fundamental differences between the experiments and analysis techniques the investigations have been separated in two chapters. The investigation of 44S, extracted via the two-proton knockout reaction from 46Ar with intermediate beam energy, is presented in chapter 2. Four new excited states are identified, of which the first 4+ state presents evidence of deformation, as suggested by line-shape simulations of the detected gamma rays. This is also indicated by a shell-model calculation, where the deformation of the first 4 + state originates in a neutron particle-hole configuration which is fundamentally different from the "intruder"configuration producing the ground state deformation and from the configuration describing the relatively long-lived isomeric 0+ state. Consequently, not three coexisting shapes, rather three coexisting configurations are found in 44S, corresponding to zero, one and two neutron particle-hole excitations. In chapter 3, results from the analysis of the 19O( d,p)20O reaction in inverse kinematics using the active gas target detector array ANASEN are presented. In order to study the location and fragmentation of the d3/2 orbital in 20O, a beam of the short-lived 19O was produced at the RESOLUT radioactive beam facility of the Florida State University. The ejected protons from the (d,p) reaction were measured with large solid angle coverage and for beam energies between 2.2 and 4.3 MeV/A. Data from the 17O(d,p)18O reaction was acquired to verify our experimental methods and analysis techniques.

  18. Decay of the neutron-rich isotope {sup 113}Ru to {sup 113}Rh

    Energy Technology Data Exchange (ETDEWEB)

    Kurpeta, J.; Plochocki, A. [Institute of Experimental Physics, Warsaw University (Poland); Lhersonneau, G.; Wang, J.C.; Dendooven, P.; Honkanen, A.; Huhta, M.; Oinonen, M.; Penttilae, H.; Peraejaervi, K.; Persson, J.R. [Department of Physics, University of Jyvaeskylae (Finland); Aeystoe, J. [Department of Physics, University of Jyvaeskylae (Finland); EP-ISOLDE, CERN, Geneva (Switzerland)

    2002-04-01

    The decay of neutron-rich isotope {sup 113}Ru obtained as on-line mass separated product of proton-induced fission has been investigated by {gamma}{gamma} coincidence and spectrum multiscaling measurements. Decay schemes for both low- and high-spin isomers of {sup 113}Ru have been constructed. The level scheme of {sup 113}Rh is considerably extended. Systematics of the lowest-lying rhodium levels is smooth. The picture of shape coexistence established for neutron-rich Rh isotopes near-neutron midshell is confirmed with the observation of a K=1/2 deformed band, with its 3/2{sup +} state at 600 keV being the lowest-lying level and of probable 7/2{sup +} and 5/2{sup +} band members. A large fraction of {beta} feeding is found to populate high-lying levels in {sup 113}Rh. The GT strength in {sup 113}Ru{sup m} decay is significantly larger than for the decay of {sup 113}Ru{sub g} and of lighter rhodium isotopes. (orig.)

  19. Development of axial asymmetry in the neutron-rich nucleus {sup 110}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H., E-mail: hiroshi@ribf.riken.jp [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, K.; Odahara, A. [Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka 560-0043 Toyonaka (Japan); Sumikama, T. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Li, Z. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Miyashita, Y. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Sato, K. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Prochniak, L. [Institute of Physics, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 1, 20-031 Lublin (Poland); Baba, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Berryman, J.S. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Blasi, N. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Bracco, A.; Camera, F. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Chiba, J. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Doornenbal, P. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Go, S.; Hashimoto, T.; Hayakawa, S. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan)

    2011-10-19

    The neutron-rich nucleus {sup 110}Mo has been investigated by means of {gamma}-ray spectroscopy following the {beta}-decay of {sup 110}Nb, produced using in-flight fission of a {sup 238}U beam at 345 MeV/nucleon at the RIBF facility. In addition to the ground-band members reported previously, spectroscopic information on the low-lying levels of the quasi-{gamma} band built on the second 2{sup +} state at 494 keV has been obtained for the first time. The experimental finding of the second 2{sup +} state being lower than the yrast 4{sup +} level suggests that axially-asymmetric {gamma} softness is substantially enhanced in this nucleus. The experimental results are compared with model calculations based on the general Bohr Hamiltonian method. The systematics of the low-lying levels in even-even A{approx}110 nuclei is discussed in comparison with that in the neutron-rich A{approx}190 region, by introducing the quantity E{sub S}/E(2{sub 1}{sup +}), E{sub S}=E(2{sub 2}{sup +})-E(4{sub 1}{sup +}), as a global signature of the structural evolution involving axial asymmetry.

  20. Coulomb Excitation of Neutron-Rich $A\\approx$140 Nuclei

    CERN Multimedia

    Van duppen, P L E

    2002-01-01

    Investigating the isospin dependence of the product between the B( E2; 0$_{1}^{+} \\rightarrow 2_{1}^{+}$)-value and the 2$_{1}^{+}$-excitation energy E$_{2^{+}}$ in even-even nuclei around $A\\!\\approx$140 one observes a rather smooth trend close to the valley of stability but clear indication for a reduction from the extrapolated B(E2)-values by one order of magnitude for some very neutron-rich nuclei. While close to the valley of stability the strong neutron-proton interaction results in an equilibration of the neutron and proton deformations with a predominate isoscalar character of the collective 2$^{+}$ excitation, it is conceivable that more loosely bound neutrons cannot polarize a close-to-magic proton core that well any more. This might result in a decoupling of the shape of the outer neutrons from the core and in a strong isovector admixture to the lowest lying 2$^{+}$ level. In this way the 2$^{+}$ -energies could be further lowered in neutron-rich nuclei, while the quadrupole moments of the proton c...

  1. New neutron-rich isotope production in 154Sm+160Gd

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2016-09-01

    Full Text Available Deep inelastic scattering in 154Sm+160Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD model and time dependent Hartree–Fock (TDHF theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with 58≤Z≤76 are observed and the production cross sections are at the order of μb to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lanthanides which are difficult to be produced with traditional fusion reactions or fission of actinides.

  2. New neutron-rich isotope production in 154Sm+160Gd

    Science.gov (United States)

    Wang, Ning; Guo, Lu

    2016-09-01

    Deep inelastic scattering in 154Sm+160Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD) model and time dependent Hartree-Fock (TDHF) theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI) for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with 58 ≤ Z ≤ 76 are observed and the production cross sections are at the order of μb to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lanthanides which are difficult to be produced with traditional fusion reactions or fission of actinides.

  3. E1 resonances in neutron-rich nuclei within the phonon damping model

    Indian Academy of Sciences (India)

    Nguyen Dinh Dang; Voung Kim Au; Toshio Suzuki; Akito Arima

    2001-08-01

    The quasiparticle representation of the phonon damping model (PDM) is developed to include the superfluid pairing correlations microscopically. The formalism is applied to calculate the photoabsorption and the electromagnetic (EM) differential cross sections of E1 excitations in neutron-rich oxygen and calcium isotopes. The calculated photoabsorption cross sections agree reasonably well with the available data for 16,18O and 40,48Ca. The results of calculations show that the change of the fraction of the E1 integrated strength in the region of pygmy dipole resonance (PDR) as a function of mass number with increasing neutron number is in agreement with the recent experimental data, and does not follow the prediction by the simple cluster model. The EM differential cross sections obtained within PDM in this work show prominent PDR peaks below 15 MeV for 20,22O in agreement with the recent experimental observation. It is also shown that, using low-energy RI beams at around 50-60 MeV/nucleon, one can observe clean and even enhanced PDR peaks without the admixture with the GDR in the EM differential cross sections of neutron-rich nuclei.

  4. Shell Evolution in the Neutron-Rich Cu and Zn Isotopes

    Science.gov (United States)

    Belarge, Joe; Bazin, Daniel; Gade, Alexandra; Ayyad, Yassid; Bender, Peter; Elder, Robert; Elman, Brandon; Iwasaki, Hiro; Kobayashi, Nobuyuki; Loelius, Charles; Longfellow, Brenden; Lunderberg, Eric; Morfouace, Pierre; Sullivan, Chris; Weisshaar, Dirk; Whitmore, Kenneth

    2016-09-01

    Recent shell model calculations predict a gradual reduction of the Z=28 shell gap in Ni isotopes as the ν 1g9 / 2 orbital is filled from 68Ni to 78Ni [Otsuka et al. PRL 95, 232502]. These predictions can be experimentally tested by measuring the spectroscopic strength of a given orbital in an isotopic chain. The neutron-rich Cu isotopes, with one proton outside of a filled π 1f7 / 2 orbital, are some of the best candidates to exhibit the effects of the underlying structure evolution in this region. The high luminosity provided by fast beam, thick target experiments performed at the NSCL, coupled with the high resolution, high efficiency gamma-ray array GRETINA, provide a unique opportunity to study the neutron-rich Cu isotopes. The current experiment aims to measure the strength of 2p-1h excitations in 69-77Cu, populated through one proton knockout from 70-78Zn beams on a Be target, thereby probing the effective single particle energy and spectroscopic strength of the π 1f7 / 2 orbital. Results from the ongoing analysis will be presented.

  5. Gamma ray spectroscopy of neutron-rich actinides after multi-nucleon transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Andreas; Birkenbach, Benedikt; Reiter, Peter; Hess, Herbert; Lewandowski, Lars; Steinbach, Tim [Institut fuer Kernphysik, Universitaet zu Koeln (Germany); Collaboration: LNL 11.22-Collaboration

    2014-07-01

    Excited states in neutron-rich Th and U nuclei were investigated after multi-nucleon transfer reactions employing the AGATA demonstrator and PRISMA setup at LNL (INFN, Italy). A primary {sup 136}Xe beam of 1 GeV hitting a {sup 238}U target was used to produce the nuclei of interest in the actinide region. Beam-like reaction products in the Xe-Ba-region were identified and selected by the PRISMA spectrometer. Kinematic coincidences between the binary reaction products of beam-like and target-like nuclei are detected with an additional MCP detector. Those coincidences allow clean conditions for in-beam γ-ray spectroscopy. Background contributions from excited fission fragments are successfully discriminated. γ-rays from excited states in beam- and target-like particles were measured with the position sensitive AGATA HPGe detectors. Improved energy resolution after Doppler correction is based on the novel γ-ray tracking technique which was successfully exploited to increase the quality of the γ-spectra. γ-ray spectra of the produced beam-like isotopes in the one-proton and two-proton transfer channels will be presented. Corresponding results from the hard-to-reach neutron-rich isotopes beyond {sup 232}Th will focus on their collective properties and cross section limits for their production.

  6. New neutron-rich isotope production in $^{154}$Sm+$^{160}$Gd

    CERN Document Server

    Wang, Ning

    2016-01-01

    Deep inelastic scattering in $^{154}$Sm+$^{160}$Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD) model and time dependent Hartree-Fock (TDHF) theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI) for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with $58 \\le Z\\le 76$ are observed and the production cross sections are at the order of ${\\rm \\mu b}$ to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lant...

  7. Recoil separators for radiative capture using radioactive ion beams. Recent advances and detection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Chris [TRIUMF, Vancouver, BC (Canada); Greife, Uwe; Hager, Ulrike [Colorado School of Mines, Golden, CO (United States)

    2014-06-15

    Radiative capture reactions involving the fusion of hydrogen or helium are ubiquitous in the stellar history of the universe, and are some of the most important reactions in the processes that govern nucleosynthesis and energy generation in both static and explosive scenarios. However, radiative capture reactions pose some of the most difficult experimental challenges due to extremely small cross sections. With the advent of recoil separators and techniques in inverse kinematics, it is now possible to measure radiative capture reactions on very short-lived radioactive nuclei, and in the presence of high experimental backgrounds. In this paper we review the experimental needs for making measurements of astrophysical importance on radiative capture reactions. We also review some of the important historical advances in the field of recoil separators as well as describe current techniques and performance milestones, including descriptions of some of the separators most recently working at radioactive ion beam facilities, such as DRAGON at TRIUMF and the DRS at the Holifield Radioactive Ion Beam Facility. We will also summarize some of the scientific highlight measurements at the RIB facilities. (orig.)

  8. Development and properties of crystalline silicotitanate (CST) ion exchangers for radioactive waste applications

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.E.; Brown, N.E.

    1997-04-01

    Crystalline silicotitanates (CSTs) are a new class of ion exchangers that were jointly invented by researchers at Sandia National Laboratories and Texas A&M University. One particular CST, known as TAM-5, is remarkable for its ability to separate parts-per-million concentrations of cesium from highly alkaline solutions (pH> 14) containing high sodium concentrations (>5M). It is also highly effective for removing cesium from neutral and acidic solutions, and for removing strontium from basic and neutral solutions. Cesium isotopes are fission products that account for a large portion of the radioactivity in waste streams generated during weapons material production. Tests performed at numerous locations with early lab-scale TAM-5 samples established the material as a leading candidate for treating radioactive waste volumes such as those found at the Hanford site in Washington. Thus Sandia developed a Cooperative Research and Development Agreement (CRADA) partnership with UOP, a world leader in developing, commercializing, and supplying adsorbents and associated process technology to commercialize and further develop the material. CSTs are now commercially available from UOP in a powder (UOP IONSIV{reg_sign} IE-910 ion exchanger) and granular form suitable for column ion exchange operations (UOP IONSIV{reg_sign} IE-911 ion exchanger). These materials exhibit a high capacity for cesium in a wide variety of solutions of interest to the Department of Energy, and they are chemically, thermally, and radiation stable. They have performed well in tests at numerous sites with actual radioactive waste solutions, and are being demonstrated in the 100,000 liter Cesium Removal Demonstration taking place at Oak Ridge National Laboratory with Melton Valley Storage Tank waste. It has been estimated that applying CSTs to the Hanford cleanup alone will result in a savings of more than $300 million over baseline technologies.

  9. New precision mass measurements of neutron-rich calcium and potassium isotopes and three-nucleon forces

    CERN Document Server

    Gallant, A T; Brunner, T; Chowdhury, U; Ettenauer, S; Lennarz, A; Robertson, D; Simon, V V; Chaudhuri, A; Holt, J D; Kwiatkowski, A A; Mané, E; Menéndez, J; Schultz, B E; Simon, M C; Andreoiu, C; Delheij, P; Pearson, M R; Savajols, H; Schwenk, A; Dilling, J

    2012-01-01

    We present precision Penning-trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system the mass of $^{51}$K was measured for the first time, and the precision of the $^{51,52}$Ca mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, $^{52}$Ca is more bound by 1.74 MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces at neutron-rich extremes.

  10. Radioactive ion beam transportation for the fundamental symmetry study with laser-trapped atoms

    Energy Technology Data Exchange (ETDEWEB)

    Arikawa, Hiroshi, E-mail: arikawa@cyric.tohoku.ac.jp; Ando, S.; Aoki, T.; Ezure, S.; Harada, K.; Hayamizu, T.; Inoue, T.; Ishikawa, T.; Itoh, M.; Kawamura, H.; Kato, K.; Kato, T.; Uchiyama, A.; Sakemi, Y. [Cyclotron and Radioisotope Center, Tohoku University, Miyagi 980-8578 (Japan); Aoki, T. [Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902 (Japan); Furukawa, T. [Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397 (Japan); Hatakeyama, A. [Department of Applied Physics, Tokyo University of Agriculture and Technology, Tokyo 184-8588 (Japan); Hatanaka, K.; Yoshida, H. P. [Research Center for Nuclear Physics, Osaka University, Osaka 606-8502 (Japan); Imai, K. [Advanced Science Research Center, Japan Atomic Energy Agency, Ibaraki 319-1184 (Japan); and others

    2014-02-15

    The search for the violation of the fundamental symmetry in a radioactive atom is the promising candidate for precision tests of the standard model and its possible extensions. The subtle signal arising from the symmetry violation is enhanced in heavy atoms, such as a francium (Fr). To realize high precision measurements, a large amount of radioactive isotopes is required. The Fr is produced via a nuclear fusion reaction using a melted gold target with a {sup 18}O primary beam at Cyclotron and Radioisotope Center, Tohoku University. The maximum extraction efficiency of the Fr ion was achieved at approximately 35%. The beam line consists of an electrostatic deflector, three electrostatic quadrupole triplets to the measurement area at 10 m away from the reaction point, and several beam diagnosis systems. We optimized parameters of the beam line.

  11. Development of a low-energy radioactive ion beam facility for the MARA separator

    Science.gov (United States)

    Papadakis, Philippos; Moore, Iain; Pohjalainen, Ilkka; Sarén, Jan; Uusitalo, Juha

    2016-12-01

    A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyväskylä, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.

  12. Development of a low-energy radioactive ion beam facility for the MARA separator

    Energy Technology Data Exchange (ETDEWEB)

    Papadakis, Philippos, E-mail: philippos.papadakis@jyu.fi; Moore, Iain; Pohjalainen, Ilkka; Sarén, Jan; Uusitalo, Juha [University of Jyväskylä, Department of Physics (Finland)

    2016-12-15

    A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyväskylä, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.

  13. Development of a low-energy radioactive ion beam facility for the MARA separator

    CERN Document Server

    Papadakis, Philippos; Pohjalainen, Ilkka; Sarén, Jan; Uusitalo, Juha

    2016-01-01

    A low-energy radioactive ion beam facility for the production and study of nuclei produced close to the proton drip line is under development at the Accelerator Laboratory of the University of Jyv\\"askyl\\"a, Finland. The facility will take advantage of the mass selectivity of the recently commissioned MARA vacuum-mode mass separator. The ions selected by MARA will be stopped and thermalised in a small-volume gas cell prior to extraction and further mass separation. The gas cell design allows for resonance laser ionisation/spectroscopy both in-gas-cell and in-gas-jet. The facility will include experimental setups allowing ion counting, mass measurement and decay spectroscopy.

  14. Penning trap mass measurements and laser spectroscopy on neutron-rich fission products extracted from the research reactor TRIGA-Mainz

    Energy Technology Data Exchange (ETDEWEB)

    Eibach, Martin; Ketelaer, Jens; Ketter, Jochen; Knuth, Konstantin [Institut fuer Physik, Universitaet Mainz (Germany); Blaum, Klaus; Nagy, Szilard [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Eberhardt, Klaus; Noertershaeuser, Wilfried [Institut fuer Kernchemie, Universitaet Mainz (Germany); Herfurth, Frank [GSI, Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Smorra, Christian [Physikalisches Institut, Universitaet Heidelberg (Germany); Institut fuer Kernchemie, Universitaet Mainz (Germany)

    2009-07-01

    TRIGA-SPEC is a setup for Penning trap mass spectrometry and collinear laser spectroscopy on short-lived neutron-rich nuclides located at the research reactor TRIGA-Mainz. It is dedicated to the determination of nuclear ground-state properties like masses and charge-radii. The nuclides are produced by neutron-induced fission of an actinide target located in a target chamber near the reactor core. It is required to extract the nuclides fast and with high efficiency from the target chamber in order to make precision experiments on short-living species with half-lives in the order of 1s. To this end, they are flushed out with a helium gas jet containing carbon aerosols and transported through a skimmer region to an ECR ion source. The characterisation of the carbon aerosol generator and the verification of transported fission products are presented.

  15. First observation of the beta decay of neutron-rich $^{218}Bi$ by the pulsed-release technique and resonant laser ionization

    CERN Document Server

    De Witte, H; Borzov, I N; Caurier, E; Cederkäll, J; De Smet, A; Eckhaudt, S; Fedorov, D V; Fedosseev, V; Franchoo, S; Górska, M; Grawe, H; Huber, G; Huyse, M; Janas, Z; Köster, U; Kurcewicz, W; Kurpeta, J; Plochocki, A; Van Duppen, P; Van de Vel, K; Weissman, L

    2004-01-01

    The neutron-rich isotope /sup 218/Bi has been produced in proton- induced spallation of a uranium carbide target at the ISOLDE facility at CERN, extracted from the ion source by the pulsed-release technique and resonant laser ionization, and its beta decay is studied for the first time. A half-life of 33(1)s was measured and is discussed in the self-consistent continuum-quasi particle-random- phase approximation framework that includes Gamow-Teller and first- forbidden transitions. A level scheme was constructed for /sup 218 /Po, and a deexcitation pattern of stretched E2 transitions 8/sup +/ to 6/sup +/ to 4/sup +/ to 2/sup +/ to 0/sup +/ to the ground state is suggested. Shell-model calculations based on the Kuo-Herling interaction reproduce the experimental results satisfactorily. (28 refs).

  16. K-isomers in Hf nuclei at and beyond the neutron-rich edge of beta-stability

    CERN Document Server

    Chowdhury, P; Seabury, E H; Walker, P M; Wheldon, C; Ahmad, I; Carpenter, M P; Hackman, G; Janssens, R V F; Khoo, T L; Nisius, D; Reiter, P

    1999-01-01

    New high-K isomers are populated in sup 1 sup 8 sup 0 sup , sup 1 sup 8 sup 1 sup , sup 1 sup 8 sup 2 Hf nuclei via inelastic excitation and transfer reactions, using pulsed sup 2 sup 3 sup 8 U beams on Hf targets. The new data explore K-hindrances for different multipolarities and the role of residual spin-spin interactions for multi-quasiparticle (qp) configurations at the neutron-rich edge of the beta-stability line. The mapping of 4-qp K-isomers in the A approx 180 region is extended into neutron-rich territory.

  17. Shell Model Predictions for Very Neutron-Rich Nuclei in 132SN Region Interesting Features of Effective- Charge Revealed

    CERN Document Server

    Sarkar, S; Sarkar, Sukhendusekhar

    2005-01-01

    Shell model studies have been done for very neutron - rich nuclei in the range Z=50-55 and N=82-87. Good agreement of the theoretical level spectra with the experimental one for N=82, 83 I and Te nuclei is shown. Then the results for three very neutron-rich nuclei 137Sn and 136-137Sb have been presented. The present calculation favour a 2- ground state for 136Sb instead of 1- identified through beta decay.Interesting observation about the E2 effective charges for this region has been discussed.

  18. Production cross sections of heavy neutron-rich nuclei approaching the nucleosynthesis r-process path around A =195

    Science.gov (United States)

    Kurtukian-Nieto, T.; Benlliure, J.; Schmidt, K.-H.; Audouin, L.; Becker, F.; Blank, B.; Casarejos, E.; Farget, F.; Fernández-Ordóñez, M.; Giovinazzo, J.; Henzlova, D.; Jurado, B.; Pereira, J.; Yordanov, O.

    2014-02-01

    In the present work we were able to synthesize and measure with high accuracy the production cross sections of more than 190 heavy neutron-rich nuclei by the in-flight fragmentation of relativistic 208Pb projectiles, 26 of which were produced for the first time. This work has shown that the N =126 region far below the doubly magic 208Pb has become accessible experimentally and represents a step further towards the study of heavy neutron-rich nuclei approaching the r-process waiting point at A =195.

  19. Investigation of the single Particle Structure of the neutron-rich Sodium Isotopes $^{27-31}\\!$Na

    CERN Multimedia

    2002-01-01

    We propose to study the single particle structure of the neutron-rich isotopes $^{27-31}\\!$Na. These isotopes will be investigated via neutron pickup reactions in inverse kinematics on a deuterium and a beryllium target. Scattered beam particles and transfer products are detected in a position sensitive detector located around 0$^\\circ$. De-excitation $\\gamma$-rays emitted after an excited state has been populated will be registered by the MINIBALL Germanium array. The results will shed new light on the structure of the neutron-rich sodium isotopes and especially on the region of strong deformation around the N=20 nucleus $^{31}\\!$Na.

  20. K-isomers in Hf nuclei at and beyond the neutron-rich edge of {beta}-stability.

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, P.; Alarcao, R. D.; Seabury, E. H.; Walker, P. M.; Wheldon, C.; Ahmad. I.; Carpenter, M. P.; Hackman, G.; Janssens, R. V. F.; Khoo, T. L.; Nisius, D.; Reiter, P.

    1999-03-30

    New high-K isomers are populated in {sup 180,181,182}Hf nuclei via inelastic excitation and transfer reactions, using pulsed {sup 238}U beams on Hf targets. The new data explore K-hindrances for different multipolarities and the role of residual spin-spin interactions for multi-quasiparticle (qp) configurations at the neutron-rich edge of the {beta}-stability line. The mapping of 4-qp K-isomers in the A {approx} 180 region is extended into neutron-rich territory.

  1. Lifetime measurements of neutron-rich nuclei around {sup 48}Ca with the CLARA-PRISMA setup

    Energy Technology Data Exchange (ETDEWEB)

    Mengoni, D.; Farnea, E. [Dipartimento di Fisica dell' Universita, Padova (Italy); INFN, Sezione di Padova, Padova (Italy); Valiente-Dobon, J.J.; Latina, A. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Gadea, A. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); CSIC-Universitat de Valencia, IFIC, Valencia (Spain); Dewald, A. [Institut fuer Kernphysik, Koeln Universitaet (Germany)

    2009-12-15

    The lifetimes of excited states in neutron-rich nuclei around the doubly-magic nucleus {sup 48}Ca have been measured using a novel technique that combines the Recoil Distance Doppler Shift method with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. The experimental method are discussed and the results for Ca nuclei are compared with realistic simulations of the CLARA and PRISMA spectrometers. (orig.)

  2. Study of Nuclear Reactions with 11C and 15O Radioactive Ion Beams

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dongwon [Univ. of California, Berkeley, CA (United States)

    2007-05-14

    Nuclear reaction study with radioactive ion beams is one of the most exciting research topics in modern nuclear physics. The development of radioactive ion beams has allowed nuclear scientists and engineers to explore many unknown exotic nuclei far from the valley of nuclear stability, and to further our understanding of the evolution of the universe. The recently developed radioactive ion beam facility at the Lawrence Berkeley National Laboratory's 88-inch cyclotron is denoted as BEARS and provides 11C, 14O and 15O radioactive ion beams of high quality. These moderate to high intensity, proton-rich radioactive ion beams have been used to explore the properties of unstable nuclei such as 12N and 15F. In this work, the proton capture reaction on 11C has been evaluated via the indirect d(11C, 12N)n transfer reaction using the inverse kinematics method coupled with the Asymptotic Normalization Coefficient (ANC) theoretical approach. The total effective 12N → 11C+p ANC is found to be (C eff12N = 1.83 ± 0.27 fm-1. With the high 11C beam intensity available, our experiment showed excellent agreement with theoretical predictions and previous experimental studies. This study also indirectly confirmed that the 11C(p,γ) reaction is a key step in producing CNO nuclei in supermassive low-metallicity stars, bypassing the slow triple alpha process. The newly developed 15O radioactive ion beam at BEARS was used to study the poorly known level widths of 16F via the p(15O,15O)p reaction. Among the nuclei in the A=16, T=1 isobaric triad, many states in 16N and 16O have been well established, but less has been reported on 16F. Four states of 16F below 1 MeV have been identified experimentally: 0-, 1

  3. Search for new physics with neutrinos at Radioactive Ion Beam facilities

    CERN Document Server

    Espinoza, Catalina; Volpe, Cristina

    2012-01-01

    We propose applications of Radioactive Ion Beam facilities to investigate physics beyond the Standard Model. In particular, we focus on the possible measurement of coherent neutrino-nucleus scattering and on a search for sterile neutrinos, by means of a low energy beta-beam with a Lorentz boost factor $\\gamma \\approx 1$. In the considered setup the collected radioactive ions are sent inside a 4$\\pi$ detector. For the first application we provide the number of events associated with neutrino-nucleus coherent scattering, when the detector is filled in with a noble liquid. For the sterile search we consider that the spherical detector is filled in with a liquid scintillator, and that the neutrino detection channel is inverse-beta decay. We provide the exclusion curves for the sterile neutrino mixing parameters, based upon the 3+1 formalism, depending upon the achievable ion intensity. Our results are obtained both for unbinned and binned events, with binning in energy and in distance. The proposed experiment rep...

  4. Research and development for the production of radioactive ions for SPIRAL; Recherche et developpement concernant la production d'ions radioactifs dans le cadre de SPIRAL

    Energy Technology Data Exchange (ETDEWEB)

    Eleon, C

    2007-12-15

    This thesis is related to the research and development program for the production of radioactive ion beams by the ISOL method for SPIRAL at GANIL. Two studies concerning improvements to the performance of SPIRAL target-source system have been made, using a statistical approach to the atoms-to-ions transformation. The first study concerns the transformation time between the production of the radioactive atoms of Ar{sup 35} inside a target and the extraction of the radioactive ions from the source with the TARGISOL set-up (target + ECR source). The goal was to determine the diffusion coefficients of the Ar for the carbon target. The results that are presented illustrate the difficulty of this work. The second study is the application of the statistical approach to the surface ionization source. It allowed one to define and to build a new MonoNaKe set-up for the production of 1{sup +} radioactive alkaline ions. Radioactive ions of K{sup 37,47}, Na{sup 25,26,27,28,30}, Li{sup 8,9} and Al{sup 28,29,30,31} were produced. For the production of the multicharged radioactive alkali ions, the MonoNaKe target/ion-source system was coupled to the ECR source of SPIRAL-1 without a mass separator (1{sup +}/N{sup +} direct method). A first radioactive ion beam of {sup 47}K{sup 5+} was extracted at the SIRa test bench. A surface ionization test source based on the same technical characteristics of MonoNaKe has been built. The goal of this system will be to define a prototype of source adapted to the constraints of SPIRAL-2 (ionization efficiency and lifetime). (author)

  5. Combined in-beam gamma-ray and conversion electron spectroscopy with radioactive ion beams

    Directory of Open Access Journals (Sweden)

    Konki J.

    2013-12-01

    Full Text Available In-beam gamma-ray and electron spectroscopy have been widely used as tools to study the broad variety of phenomena in nuclear structure. The SPEDE spectrometer is a new device to be used in conjunction with the MINIBALL germanium detector array to enable the detection of internal conversion electrons in coincidence with gamma rays from de-exciting nuclei in radioactive ion beam experiments at the upcoming HIE-ISOLDE facility at CERN, Switzerland. Geant4 simulations were carried out in order to optimise the design and segmentation of the silicon detector to achieve good energy resolution and performance.

  6. Increased rigidly triaxial deformations in neutron-rich Mo, Ru isotopes

    Science.gov (United States)

    Liang, WuYang; Jiao, ChangFeng; Xu, FuRong; Fu, XiMing

    2016-09-01

    Pairing-deformation-frequency self-consistent crankingWoods-Saxon model is employed to investigate the triaxiality in the ground states of the neutron-rich even-even Mo, Ru isotopes. Deformation evolutions and transition probabilities have been studied, giving the triaxial shapes in their ground states. The kinematic moments of inertia have been calculated to illustrate the gradually rigid deformation. To understand the origin of the asymmetry shape in this region, we analyze the evolution of single-particle orbits with changing γ deformation. The present calculations reveal the importance of the triaxial deformation in describing not only static property, but also rotational behaviors in this mass region, providing significant probes into the shell structure around.

  7. Competing $\\gamma$-rigid and $\\gamma$-stable vibrations in neutron rich Gd and Dy isotopes

    CERN Document Server

    Budaca, R

    2015-01-01

    An exactly separable version of the Bohr Hamiltonian which combines the $\\gamma$-stable and $\\gamma$-rigid axial vibration-rotation is used to describe the collective properties of few neutron rich transitional nuclei. The coupling between the two types of collective motion is managed through a rigidity parameter which also influences the geometry of the shape-phase space. While the $\\gamma$-angular part of the problem associated to axially symmetric shapes is treated within the small angles approximation and the stiff $\\gamma$ oscillation hypothesis, the $\\beta$ vibration is described by means of a Davidson potential. The resulting model have three free parameters not counting the scale and was successfully applied for the description of the collective spectra for few heavier isotopes of Gd and Dy. In both cases a critical nucleus was identified through a discontinuous behavior in respect to the rigidity parameter and relevant experimental observables.

  8. Shell quenching in Ni78: A hint from the structure of neutron-rich copper isotopes

    Science.gov (United States)

    Sieja, K.; Nowacki, F.

    2010-06-01

    Recent progress in experimental techniques allows us to study very exotic systems like neutron-rich nuclei in the vicinity of Ni78. The spectroscopy of this region can nowadays be studied theoretically in the large scale shell model calculations. In this work, we perform a shell model study of odd copper nuclei with N=40-50, in a large valence space with the Ca48 core, using a realistic interaction derived from the CD-Bonn potential. We present the crucial importance of the proton core excitations for the description of spectra and magnetic moments, which are for the first time correctly reproduced in theoretical calculations. Shell evolution from Ni68 to Ni78 is discussed in detail. A weakening of the Z=28 gap when approaching the N=50 shell closure, suggested by the experimental evidence, is confirmed in the calculations.

  9. Dipole response in neutron-rich nuclei within self-consistent approaches using realistic potentials

    Directory of Open Access Journals (Sweden)

    Lo Iudice N.

    2015-01-01

    Full Text Available A nucleon-nucleon chiral potential with a corrective density dependent term simulating a three-body force is used in a self-consistent calculation of the dipole strength distribution in neutron-rich nuclei, with special attention to the low-lying spectra associated to the pygmy resonance. A Hartree-Fock-Bogoliubov basis is generated and adopted in Tamm-Dancoff and random-phase approximations and, then, in an equation of motion approach which includes a basis of two-phonon states. The direct use of the mentioned chiral potential improves the description of both giant and pygmy dipole modes with respect to other realistic interactions. Moreover, the inclusion of the two-phonon states induces a pronounced fragmentation of the giant resonance and enhances the density of the low-lying levels in the pygmy region in agreement with recent experiments.

  10. New multi-phonon gamma vibrational bands in A~110 neutron-rich nuclei

    Institute of Scientific and Technical Information of China (English)

    HAMILTON; J; H; RAMAYYA; A; V; RASMUSSEN; J; O; HWANG; J; K; YEOH; E; Y

    2011-01-01

    The high spin states of neutron-rich 103Nb, 107Tc and 109Tc nuclei in A~110 region have been investigated by measuring prompt γ-γ-γ coincident measurements populated with the spontaneous fission of 252Cf with the Gammasphere detector array. In 103Nb, one-phonon K = 9/2 and two-phonon K = 13/2 γ-vibrational bands have been identified. In 107Tc and 109Tc, one-phonon K = 11/2 and two-phonon K = 15/2 γ-vibrational bands, in which the zero-phonon bands are based on K=7/2 excited states, have also been identified. The two-phonon bands are first observed in odd-Z nuclei. The characteristics for these band structures have been discussed.

  11. Gamow-Teller response in deformed even and odd neutron-rich Zr and Mo isotopes

    CERN Document Server

    Sarriguren, P; Pereira, J

    2014-01-01

    Beta-decay properties of neutron-rich Zr and Mo isotopes are investigated within a microscopic theoretical approach based on the proton-neutron quasiparticle random-phase approximation. The underlying mean field is described self-consistently from deformed Skyrme Hartree-Fock calculations with pairing correlations. Residual separable particle-hole and particle-particle forces are also included in the formalism. The structural evolution in these isotopic chains including both even and odd isotopes is analyzed in terms of the equilibrium deformed shapes. Gamow-Teller strength distributions, beta-decay half-lives, and beta-delayed neutron-emission probabilities are studied, stressing their relevance to describe the path of the nucleosynthesis rapid neutron capture process.

  12. Proton-hole states in the N=30 neutron-rich {sup 49}K isotope.

    Energy Technology Data Exchange (ETDEWEB)

    Broda, R.; Wrzesinski, J.; Gadea, A.; Marginean, N.; Fornal, B.; Carpenter, M. P.; Janssens, R. V. F.; Zhu, S. (Physics); (Niewodniczanski Inst. of Nuclear Physics); (INFN Lab. Nazionali di Legnaro); (Dipartimento di Fisica dell' Universita); (INFN-Sezione di Napoli); (Michigan State Univ.); (National Inst. for Physics and Nuclear Engineering); (Ruder Boskovic Inst.); (CSIC-Univ. de Valencia); (Univ. of West of Scotland)

    2010-09-22

    Excited states in the N=30 neutron-rich isotope {sup 49}K have been studied using multinucleon transfer reactions with thin targets and the PRISMA-CLARA spectrometer combined with thick-target {gamma}-coincidence data from Gammasphere. The d{sub 3/2} proton-hole state is located 92 keV above the s{sub 1/2} ground state, and the proton-particle f{sub 7/2} state is suggested at 2104 keV. Three other levels are established as involving the coupling to 2{sup +} of two neutrons above the N=28 shell. The measured or estimated lifetimes served to reinforce the interpretation of the observed level structure, which is found to be in satisfactory agreement with shell-model calculations.

  13. Impact of triaxiality on the rotational structure of neutron-rich rhenium isotopes

    Directory of Open Access Journals (Sweden)

    M.W. Reed

    2016-01-01

    Full Text Available A number of 3-quasiparticle isomers have been found and characterised in the odd-mass, neutron-rich, 187Re, 189Re and 191Re nuclei, the latter being four neutrons beyond stability. The decay of the isomers populates states in the rotational bands built upon the 9/2−[514] Nilsson orbital. These bands exhibit a degree of signature splitting that increases with neutron number. This splitting taken together with measurements of the M1/E2 mixing ratios and with the changes observed in the energy of the gamma-vibrational band coupled to the 9/2−[514] state, suggests an increase in triaxiality, with γ values of 5°, 18° and 25° deduced in the framework of a particle-rotor model.

  14. $\\beta$-decay study of neutron-rich Tl and Pb isotopes

    CERN Multimedia

    It is proposed to study the structure of neutron-rich nuclei beyond $^{208}$Pb. The one-proton hole $^{211-215}$Tl and the semi magic $^{213}$Pb will be produced and studied via nuclear and atomic spectroscopy searching for long-lived isomers and investigating the $\\beta$-delayed $\\gamma$- emission to build level schemes. Information on the single particle structure in $^{211-215}$Pb, especially the position of the g$_{9/2}$ and i$_{11/2}$ neutron orbitals, will be extracted along with lifetimes. The $\\beta$-decay will be complemented with the higher spin selectivity that can be obtained by resonant laser ionization to single-out the decay properties of long-living isomers in $^{211,213}$Tl and $^{213}$Pb.

  15. Neutron density distributions of neutron-rich nuclei studied with the isobaric yield ratio difference

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Chun-Wang; Bai, Xiao-Man; Yu, Jiao; Wei, Hui-Ling [Henan Normal University, Institute of Particle and Nuclear Physics, Xinxiang (China)

    2014-09-15

    The isobaric yield ratio difference (IBD) between two reactions of similar experimental setups is found to be sensitive to nuclear density differences between projectiles. In this article, the IBD probe is used to study the density variation in neutron-rich {sup 48}Ca. By adjusting diffuseness in the neutron density distribution, three different neutron density distributions of {sup 48}Ca are obtained. The yields of fragments in the 80A MeV {sup 40,} {sup 48}Ca + {sup 12}C reactions are calculated by using a modified statistical abrasion-ablation model. It is found that the IBD results obtained from the prefragments are sensitive to the density distribution of the projectile, while the IBD results from the final fragments are less sensitive to the density distribution of the projectile. (orig.)

  16. Observation of Rotational Bands in Neutron-Rich 106Mo Nucleus

    Institute of Scientific and Technical Information of China (English)

    许瑞清; 甘翠云; 张征; 姜卓; 肖树冬; W.C.Ma; J.Kormicki; E. F. Jones; J. D. Cole; R. Aryaeinejad; M. W. Drigert; 朱胜江; I. Y. Lee; J. O. Rasmussen; M. A. Stoyer; G. M. Ter-Akopian; A. V. Daniel; J.H.Hamilton; A.V.Ramayya; J K.Hwang; X.Q.Zhang; 李科; 杨利明; 朱凌燕

    2002-01-01

    The rotational bands up to a spin of 16h in the neutron-rich 106Mo nucleus have been investigated by measuring high-fold prompt γ-ray coincidence events following spontaneous fission of 252 Cf with a Gammasphere detector array. The ground-state band, the one-phonon and two-phonon γ-vibrational bands, as well as a quasi-particle band have been confirmed and expanded. The other four collective rotational bands, three proposed as twoquasi-particle bands and one proposed as a β-vibrational band, have been newly observed. The characteristics of these collective bands and the possible configurations for the quasi-particle bands are discussed.

  17. Electric quadrupole moment of the neutron-rich {sup 33}Al

    Energy Technology Data Exchange (ETDEWEB)

    Nagatomo, T.; Ichikawa, Y.; Kameda, D.; Yoshimi, A.; Ueno, H. [RIKEN Nishina Center Wako, Saitama (Japan); Shimada, K. [Tohoku University, Miyagi (Japan); Asahi, K.; Hasama, Y. [Tokyo Institute of Technology, Tokyo (Japan); Balabanski, D.L. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Daugas, J.M.; Gaudefroy, L.; Morel, P. [CEA/DIF/DPTA/PN, BP 12, Bruyeres le Chatel (France); Depuydt, M.; De Rydt, M.; Vanderheijden, W.; Vermeulen, N.; Vingerhoets, P.; Neyens, G. [K.U. Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Grevy, S.; Stoedel, C.; Thomas, J.C. [Grand Accelerateur National d' Ions Lourds, BP 55027, Caen codex 5 (France); Perrot, L. [Institut de Physique Nuclelaire, Orsay (France)

    2009-12-15

    The nuclear electric quadrupole moment (Q moment) of the neutron-rich nucleus {sup 33}Al(I=5/2,T{sub 1/2} =41 ms) has been measured by the {beta} -ray detected nuclear quadrupole resonance ({beta} -NQR) method for the first time. The {sup 33}Al nucleus is considered to be on the border of the island of inversion within which a significant intrusion of the pf orbits occurs across the N=20 shell gap and the intrusion causes an anomalous enhancement of the Q moment. Polarized {sup 33}Al nuclei were produced from {sup 36}S (77.5MeV/u) beams through the fragmentation process and separated by LISE fragment separator at GANIL. The {sup 33}Al nuclei were implanted into a Al{sub 2}O{sub 3} single-crystal plate and the {beta} -NQR spectrum was successfully obtained. (orig.)

  18. Study of the nuclear matter distribution in neutron-rich Li isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dobrovolsky, A.V. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation)]. E-mail: dobrov@pnpi.spb.ru; Alkhazov, G.D. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Andronenko, M.N. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Bauchet, A. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Egelhof, P. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Fritz, S. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Geissel, H. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Gross, C. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Khanzadeev, A.V. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Korolev, G.A. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Kraus, G. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Lobodenko, A.A. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Muenzenberg, G. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Mutterer, M. [Institut fuer Kernphysik (IKP), TU-Darmstadt, 64289 Darmstadt (Germany); Neumaier, S.R. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Institut fuer Kernphysik (IKP), TU-Darmstadt, 64289 Darmstadt (Germany); Schaefer, T. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Scheidenberger, C. [Gesellschaft fuer Schwerionenforschung (GSI), 64291 Darmstadt (Germany); Seliverstov, D.M. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Timofeev, N.A. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation); Vorobyov, A.A.; Yatsoura, V.I. [Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina (Russian Federation)

    2006-02-20

    The differential cross sections for small-angle proton elastic scattering on the {sup 6,8,9,11}Li nuclei at energies near 700 MeV/nucleon were measured in inverse kinematics using secondary nuclear beams at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR was employed as target and recoil proton detector. For determining the nuclear matter radii and radial matter distributions, the measured cross sections have been analysed with the aid of the Glauber multiple-scattering theory. The nuclear matter distribution deduced for {sup 11}Li exhibits a very pronounced halo structure, the matter radius of {sup 11}Li being significantly larger than those of the {sup 6,8,9}Li isotopes. The data on {sup 8,9}Li are consistent with the existence of sizable neutron skins in these nuclei. The obtained data allow for a test of various theoretical model calculations of the structure of the studied neutron-rich nuclei.

  19. Evidence for a smooth onset of deformation in the neutron-rich Kr isotopes

    CERN Document Server

    Albers, M; Nomura, K; Blazhev, A; Jolie, J; Mucher, D; Bastin, B; Bauer, C; Bernards, C; Bettermann, L; Bildstein, V; Butterworth, J; Cappellazzo, M; Cederkall, J; Cline, D; Darby, I; Das Gupta, S; Daugas, J M; Davinson, T; De Witte, H; Diriken, J; Filipescu, D; Fiori, E; Fransen, C; Gaffney, L P; Georgiev, G; Gernhauser, R; Hackstein, M; Heinze, S; Hess, H; Huyse, M; Jenkins, D; Konki, J; Kowalczyk, M; Kroll, T; Krucken, R; Litzinger, J; Lutter, R; Marginean, N; Mihai, C; Moschner, K; Napiorkowski, P; Nara Singh, B S; Nowak, K; Otsuka, T; Pakarinen, J; Pfeiffer, M; Radeck, D; Reiter, P; Rigby, S; Robledo, L M; Rodriguez-Guzman, R; Rudigier, M; Sarriguren, P; Scheck, M; Seidlitz, M; Siebeck, B; Simpson, G; Thole, P; Thomas, T; Van de Walle, J; Van Duppen, P; Vermeulen, M; Voulot, D; Wadsworth, R; Wenander, F; Wimmer, K; Zell, K O; Zielinska, M

    2012-01-01

    The neutron-rich nuclei $^{94,96}$Kr were studied via projectile Coulomb excitation at the REX-ISOLDE facility at CERN. Level energies of the first excited 2$^{+}$ states and their absolute $E2$ transition strengths to the ground state are determined and discussed in the context of the $E(2^{+}_{1})$ and $B(E2;2^{+}_{1} \\rightarrow 0^{+}_{1})$ systematics of the krypton chain. Contrary to previously published results no sudden onset of deformation is observed. This experimental result is supported by a new proton-neutron interacting boson model calculation based on the constrained Hartree-Fock-Bogoliubov approach using the microscopic Gogny-D1M energy density functional.

  20. Stellar electron capture rates on neutron-rich nuclei and their impact on core-collapse

    CERN Document Server

    Raduta, Ad R; Oertel, M

    2016-01-01

    During the late stages of gravitational core-collapse of massive stars, extreme isospin asymmetries are reached within the core. Due to the lack of microscopic calculations of electron capture (EC) rates for all relevant nuclei, in general simple analytic parameterizations are employed. We study here several extensions of these parameterizations, allowing for a temperature, electron density and isospin dependence as well as for odd-even effects. The latter extra degrees of freedom considerably improve the agreement with large scale microscopic rate calculations. We find, in particular, that the isospin dependence leads to a significant reduction of the global EC rates during core collapse with respect to fiducial results, where rates optimized on calculations of stable $fp$-shell nuclei are used. Our results indicate that systematic microscopic calculations and experimental measurements in the $N\\approx 50$ neutron rich region are desirable for realistic simulations of the core-collapse.

  1. Beta-decay properties of neutron-rich medium-mass nuclei

    Science.gov (United States)

    Sarriguren, Pedro

    2016-06-01

    β-decay properties of even-even and odd-A neutron-rich Ge, Se, Kr, Sr, Zr, Mo, Ru, and Pd isotopes involved in the astrophysical rapid neutron capture process are studied within a microscopic proton-neutron quasiparticle random-phase approximation. The underlying mean field is based on a self-consistent Skyrme Hartree-Fock + BCS calculation that includes deformation as a key ingredient. The isotopic evolution of the various nuclear equilibrium shapes and the corresponding charge radii are investigated in all the isotopic chains. The energy distributions of the Gamow-Teller strength, as well as the β-decay half-lives are discussed and compared with the available experimental information. It is shown that nuclear deformation plays a significant role in the description of the decay properties in this mass region. Reliable predictions of the strength distributions are essential to evaluate decay rates in astrophysical scenarios.

  2. Gamma Vibrational Bands and Chiral Doublet Bands in A≈100 Neutron-rich Nuclei

    Institute of Scientific and Technical Information of China (English)

    ZHU Sheng-jiang; DING Huai-bo; J.H.Hamilton; A.V.Ramayya; CHE Xing-lai; J.K.Hwang; Y.X.Luo; J.O.Rasmussen; K.Li; WANG Jian-guo; XU Qiang; GU Long; YANG Yun-yi; S.Frauendorf; V.Dimitrov

    2009-01-01

    The level structures of neutron-rich ~(105)Mo,~(106)Mo,~(108)Mo and 110Ru nuclei in A≈100 region have been carefully investigated by coincidence measurements of the prompt γ-rays populated in the spontaneous fission of ~(252)Cf with the Gammasphere detector array.In 105Mo,one-phonon K =9/2 and two-phonon K=13/2 γ-vibrational bands have been identified.In ~(108)Mo,one-phonon γ-vibrational band is expanded and two-phonon γ-vibrational band has been identified.Two similar sets of bands in ~(106)Mo and ~(110)Ru are observed to high spins,which have been proposed as the soft chiral γ-vibrational bands.The characteristics for these γ-vibrational bands and chiral doublet bands have been discussed.

  3. Fusion reaction around the Coulomb barrier with neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Atsushi [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1997-07-01

    Two fusion reactions with neutron-rich nuclei are reported in this work. On the first reaction: {sup 9,10,11}Be+{sup 209}Bi, the fusion cross sections around the coulomb barrier were measured by determing {alpha} disintegration from compound nucleus Fr. In the field of 10-100 mb, the same total fusion cross sections were obtained. The phenomenon {sup 11}Be(neutron halo nucleus) alone increased and decreased was not observed. The fusion cross sections of {sup 27,29,31}Al+{sup 197}Au system were determined by using 130 kcps and 30 kcps of beam strength of {sup 29,31}Al, respectively. The value of {sup 27}Al was reproduced by calculation, but that of {sup 29}Al increased around barrier which could not be explained by CCDEF calculation. (S.Y.)

  4. Isospin dependence of nucleon effective masses in neutron-rich matter

    CERN Document Server

    Li, Bao-An; Chen, Lie-Wen; Li, Xiao-Hua

    2016-01-01

    In this talk, we first briefly review the isospin dependence of the total nucleon effective mass $M^{\\ast}_{J}$ inferred from analyzing nucleon-nucleus scattering data within an isospin dependent non-relativistic optical potential model, and the isospin dependence of the nucleon E-mass $M^{\\ast,\\rm{E}}_{J}$ obtained from applying the Migdal-Luttinger theorem to a phenomenological single-nucleon momentum distribution in nuclei constrained by recent electron-nucleus scattering experiments. Combining information about the isospin dependence of both the nucleon total effective mass and E-mass, we then infer the isospin dependence of nucleon k-mass using the well-known relation $M^{\\ast}_{J}=M^{\\ast,\\rm{E}}_{J}\\cdot M^{\\ast,\\rm{k}}_{J}$. Implications of the results on the nucleon mean free path (MFP) in neutron-rich matter are discussed.

  5. Beta decay studies of neutron-rich nuclei around N=40

    CERN Document Server

    Sorlin, O

    2001-01-01

    Beta decay studies of neutron-rich nuclei at or around N=40 are presented in the Co, Mn and V isotopic chains aiming to aimig to study excited states in Ni, Fe and Cr isotopes respectively. Examples are taken from experimental studies achieved at Louvain la Neuve, CERN/ISOLDE and GANIL/LISE facilities. Increases in production rates in the last five years has brought a dramatic change in the spectroscopic knowledge in the region of mass when the isospin number is increased. If the spherical N=40 subshell is well-established for 68Ni, its effect is steadily decreased when proceeding towards 64Cr which lies at the mid-distance between Z=20 and Z=28 magic shells

  6. Isomer Spectoscopy of Neutron-Rich {sup 168}Tb{sub 103}

    Energy Technology Data Exchange (ETDEWEB)

    Gurgi, L. A.; Regan, P. H.; Soderstrom, P. -A.; Watanabe, H.; Walker, P. M.; Podolyak, Zs.; Nishimura, S.; Berry, T. A.; Doornenbal, P.; Lorusso, G.; Kondev, F. G.

    2017-11-01

    In-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm thick 9Be target has been used to produce and study the decays of a range of neutron-rich nuclei centred around the doubly mid-shell nucleus 170Dy at the RIBF Facility, RIKEN, Japan. The produced secondary fragments of interest were identified event-by-event using the BigRIPS separator. The fragments were implanted into the WAS3ABI position sensitive silicon active stopper which allowed pixelated correlations between implants and their subsequent β-decay. Discrete γ-ray transitions emitted following decays from either metastable states or excited states populated following beta decay were identified using the 84 coaxial high-purity germanium (HPGe) detectors of the EURICA spectrometer, which was complemented by 18 additional cerium-doped lanthanum bromide (LaBr3) fast-timing scintillation detectors from the FATIMA collaboration. This paper presents the internal decay of a metastable isomeric excited state in the odd-odd nucleus 168Tb, which corresponds to a single proton-neutron hole configuration in the valence maximum nucleus 170Dy. These data represent the first information on excited states in this nucleus, which is the most neutron-rich odd-odd isotope of terbium (Z=65) studied to date. Nilsson configurations associated with an axially symmetric, prolate-deformed nucleus are proposed for the 168Tb ground state the observed isomeric state by comparison with Blocked BCS-Nilsson calculations.

  7. Capture of toxic radioactive and heavy metal ions from water by using titanate nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jiasheng, E-mail: jiashengxu@bhu.edu.cn [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Zhang, He; Zhang, Jie [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Kim, Eui Jung [School of Chemical Engineering and Bioengineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of)

    2014-11-25

    Highlights: • Three types of titanate nanofibers were prepared via a hydrothermal porcess. • These nanofibers show availability for removal of the toxic ions from water. • The equilibrium data were fitted well with the Langmuir model. - Abstract: Three types of titanate nanofibers (sodium titanate nanofibers (TNF-A), potassium/sodium titanate nanofibers (TNF-B), potassium titanate nanofibers (TNF-C)) were prepared via a hydrothermal treatment of anatase powders in different alkali solutions at 170 °C for 96 h, respectively. The as-prepared nanofibers have large specific surface area and show availability for the removal of radioactive and heavy metal ions from water system, such as Ba{sup 2+} (as substitute of {sup 226}Ra{sup 2+}) and Pb{sup 2+} ions. The TNF-A shows a better capacity in the removal of Ba{sup 2+} and Pb{sup 2+} than TNF-B and TNF-C. Structural characterization of the materials was performed with powder X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). It is found that the equilibrium data fit well with the Langmuir model. This study highlights that nanoparticles of inorganic ion exchangers with layered structure are potential materials for efficient removal of the toxic ions from contaminated water.

  8. Materials science and biophysics applications at the ISOLDE radioactive ion beam facility

    CERN Document Server

    Wahl, U

    2011-01-01

    The ISOLDE isotope separator facility at CERN provides a variety of radioactive ion beams, currently more than 800 different isotopes from ~65 chemical elements. The radioisotopes are produced on-line by nuclear reactions from a 1.4 GeV proton beam with various types of targets, outdiffusion of the reaction products and, if possible, chemically selective ionisation, followed by 60 kV acceleration and mass separation. While ISOLDE is mainly used for nuclear and atomic physics studies, applications in materials science and biophysics account for a significant part (currently ~15%) of the delivered beam time, requested by 18 different experiments. The ISOLDE materials science and biophysics community currently consists of ~80 scientists from more than 40 participating institutes and 21 countries. In the field of materials science, investigations focus on the study of semiconductors and oxides, with the recent additions of nanoparticles and metals, while the biophysics studies address the toxicity of metal ions i...

  9. Shell Model Embedded in the Continuum for Binding Systematics in Neutron-Rich Isotopes of Oxygen and Fluor

    CERN Document Server

    Luo, Y; Ploszajczak, M; Michel, N

    2002-01-01

    Continuum coupling correction to binding energies in the neutron rich oxygen and fluorine isotopes is studied using the Shell Model Embedded in the Continuum. We discuss the importance of different effects, such as the position of one-neutron emission threshold, the effective interaction or the number of valence particles on the magnitude of this correction.

  10. Materials science and biophysics applications at the ISOLDE radioactive ion beam facility

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, U., E-mail: uwahl@itn.pt [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal)

    2011-12-15

    The ISOLDE isotope separator facility at CERN provides a variety of radioactive ion beams, currently more than 800 different isotopes from {approx}70 chemical elements. The radioisotopes are produced on-line by nuclear reactions from a 1.4 GeV proton beam with various types of targets, outdiffusion of the reaction products and, if possible, chemically selective ionisation, followed by 60 kV acceleration and mass separation. While ISOLDE is mainly used for nuclear and atomic physics studies, applications in materials science and biophysics account for a significant part (currently {approx}15%) of the delivered beam time, requested by 18 different experiments. The ISOLDE materials science and biophysics community currently consists of {approx}80 scientists from more than 40 participating institutes and 21 countries. In the field of materials science, investigations focus on the study of semiconductors and oxides, with the recent additions of nanoparticles and metals, while the biophysics studies address the toxicity of metal ions in biological systems. The characterisation methods used are typical radioactive probe techniques such as Moessbauer spectroscopy, perturbed angular correlation, emission channeling, and tracer diffusion studies. In addition to these 'classic' methods of nuclear solid state physics, also standard semiconductor analysis techniques such as photoluminescence or deep level transient spectroscopy profit from the application of radioactive isotopes, which helps them to overcome their chemical 'blindness' since the nuclear half life of radioisotopes provides a signal that changes in time with characteristic exponential decay or saturation curves. In this presentation an overview will be given on the recent research activities in materials science and biophysics at ISOLDE, presenting some of the highlights during the last five years, together with a short outlook on the new developments under way.

  11. Proceedings of the workshop on the science of intense radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    McClelland, J.B.; Vieira, D.J. (comps.)

    1990-10-01

    This report contains the proceedings of a 2-1/2 day workshop on the Science of Intense Radioactive Ion Beams which was held at the Los Alamos National Laboratory on April 10--12, 1990. The workshop was attended by 105 people, representing 30 institutions from 10 countries. The thrust of the workshop was to develop the scientific opportunities which become possible with a new generation intense Radioactive Ion Beam (RIB) facility, currently being discussed within North America. The workshop was organized around five primary topics: (1) reaction physics; (2) nuclei far from stability/nuclear structure; (3) nuclear astrophysics; (4) atomic physics, material science, and applied research; and (5) facilities. Overview talks were presented on each of these topics, followed by 1-1/2 days of intense parallel working group sessions. The final half day of the workshop was devoted to the presentation and discussion of the working group summary reports, closing remarks and a discussion of future plans for this effort.

  12. A linear radiofrequency quadrupole ion trap for the cooling and bunching of radioactive ion beams

    CERN Document Server

    Kellerbauer, A G; Dilling, J; Henry, S; Herfurth, F; Kluge, H J; Lamour, E; Moore, R B; Scheidenberger, C; Schwarz, S; Sikler, G; Szerypo, J

    2002-01-01

    A linear radiofrequency quadrupole ion guide and beam buncher has been installed at the ISOLTRAP mass spectrometry experiment at the ISOLDE facility at CERN. The apparatus is being used as a beam cooling, accumulation, and bunching system. It operates with a buffer gas that cools the injected ions and converts the quasicontinuous 60- keV beam from the ISOLDE facility to 2.5-keV beam pulses with improved normalized transverse emittance. Recent measurements suggest a capture efficiency of the ion guide of up to 40% and a cooling and bunching efficiency of at least 12% which is expected to still be increased. The improved ISOLTRAP setup has so far been used very successfully in three on-line experiments. (12 refs).

  13. Development of a surface ionization source for the production of radioactive alkali ion beams in SPIRAL

    Energy Technology Data Exchange (ETDEWEB)

    Eleon, C. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France)], E-mail: sceleon@triumf.ca; Jardin, P.; Gaubert, G.; Saint-Laurent, M.-G.; Alcantara-Nunez, J.; Alves Conde, R.; Barue, C.; Boilley, D.; Cornell, J. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Delahaye, P. [3 CERN ISOLDE, 1211 Geneva 23 (Switzerland); Dubois, M.; Jacquot, B.; Leherissier, P.; Leroy, R.; Lhersonneau, G. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Marie-Jeanne, M. [3 CERN ISOLDE, 1211 Geneva 23 (Switzerland); Maunoury, L. [CIRIL, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Pacquet, J.Y.; Pellemoine, F. [GANIL, CEA/DSM CNRS/IN2P3, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France); Pierret, C. [CIRIL, Bd H. Becquerel, BP 55027, 14076 CAEN cedex 5 (France)] (and others)

    2008-10-15

    In the framework of the production of radioactive alkali ion beams by the isotope separation on-line (ISOL) method in SPIRAL I, a surface ionization source has been developed at GANIL to produce singly-charged ions of Li, Na and K. This new source has been designed to work in the hostile environment whilst having a long lifetime. This new system of production has two ohmic heating components: the first for the target oven and the second for the ionizer. The latter, being in carbon, offers high reliability and competitive ionization efficiency. This surface ionization source has been tested on-line using a {sup 48}Ca primary beam at 60.3 A MeV with an intensity of 0.14 pA. The ionization efficiencies obtained for Li, Na and K are significantly better than the theoretical values of the ionization probability per contact. The enhanced efficiency, due to the polarization of the ionizer, is shown to be very important also for short-lived isotopes. In the future, this source will be associated with the multicharged electron-cyclotron-resonance (ECR) ion source NANOGAN III for production of multicharged alkali ions in SPIRAL. The preliminary tests of the set up are also presented in this contribution.

  14. Criteria for selection of target materials and design of high-efficiency-release targets for radioactive ion beam generation

    CERN Document Server

    Alton, G D; Liu, Y

    1999-01-01

    In this report, we define criteria for choosing target materials and for designing, mechanically stable, short-diffusion-length, highly permeable targets for generation of high-intensity radioactive ion beams (RIBs) for use at nuclear physics and astrophysics research facilities based on the ISOL principle. In addition, lists of refractory target materials are provided and examples are given of a number of successful targets, based on these criteria, that have been fabricated and tested for use at the Holifield Radioactive Ion Beam Facility (HRIBF).

  15. Neutron-rich Λ-Hypernuclei study with the FINUDA experiment

    Directory of Open Access Journals (Sweden)

    Botta E.

    2014-03-01

    Full Text Available The FINUDA experiment at DAΦNE, Frascati, has found evidence for the neutron-rich hypernucleus HΛ6${}_ \\wedge ^6{\\rm{H}}$ studying (π+, π− pairs in coincidence from the Kstop−+L6i→HΛ6+π+$K_{{\\rm{stop}}}^ - + {}^{\\rm{6}}{\\rm{Li}} \\to {}_ \\wedge ^6{\\rm{H}} + {\\pi ^ + }$ production reaction followed by HΛ6→H6e +π−${}_ \\wedge ^6{\\rm{H}} \\to {}^6{\\rm{He + }}{\\pi ^ - }$ weak decay. The production rate of HΛ6${}_ \\wedge ^6{\\rm{H}}$ undergoing this two-body π− decay has been found to be (2.9±2.0⋅10−6/Kstop−$(2.9 \\pm 2.0 \\cdot {10^{ - 6}}/K_{{\\rm{stop}}}^ - $. Its binding energy has been evaluated to be BΛ(HΛ6=(4.0±1.1${B_ \\wedge }({}_ \\wedge ^6H = (4.0 \\pm 1.1$ MeV with respect to (H5+Λ$({}^5{\\rm{H}} + \\Lambda $, jointly from production and decay. A systematic difference of (0.98 ± 0.74 MeV between BΛ values derived separately from decay and from production has been tentatively assigned to the HΛ6 0g.s.+→1+${}_\\Lambda ^6{\\rm{H 0}}_{{\\rm{g}}{\\rm{.s}}{\\rm{.}}}^ + \\to {1^ + }$ excitation. A similar investigation has been carried out for the neutron-rich hypernucleus HΛ9e${}_\\Lambda ^9{\\rm{He}}$ studying the Kstop−+B9e→HΛ9e+π+$K_{{\\rm{stop}}}^ - + {}_{}^{\\rm{9}}{\\rm{Be}} \\to {}_\\Lambda ^9{\\rm{He}} + {\\pi ^ + }$ reaction in coincidence with the H Λ 9e→ L 9i +  π −${}_\\Lambda ^9{\\rm{He}} \\to {}_{}^{\\rm{9}}{\\rm{Li + }}{\\pi ^ - }$ weak decay; an upper limit for the production rate of HΛ9e${}_\\Lambda ^9{\\rm{He}}$ undergoing the two-body π− decay has been found to be 4.2⋅10 −6 /K stop− $4.2 \\cdot {10^{ - 6}}/{\\rm{K}}_{stop}^ - $ (90% C.L..

  16. Lifetime measurement of neutron-rich even-even molybdenum isotopes

    Science.gov (United States)

    Ralet, D.; Pietri, S.; Rodríguez, T.; Alaqeel, M.; Alexander, T.; Alkhomashi, N.; Ameil, F.; Arici, T.; Ataç, A.; Avigo, R.; Bäck, T.; Bazzacco, D.; Birkenbach, B.; Boutachkov, P.; Bruyneel, B.; Bruce, A. M.; Camera, F.; Cederwall, B.; Ceruti, S.; Clément, E.; Cortés, M. L.; Curien, D.; De Angelis, G.; Désesquelles, P.; Dewald, M.; Didierjean, F.; Domingo-Pardo, C.; Doncel, M.; Duchêne, G.; Eberth, J.; Gadea, A.; Gerl, J.; Ghazi Moradi, F.; Geissel, H.; Goigoux, T.; Goel, N.; Golubev, P.; González, V.; Górska, M.; Gottardo, A.; Gregor, E.; Guastalla, G.; Givechev, A.; Habermann, T.; Hackstein, M.; Harkness-Brennan, L.; Henning, G.; Hess, H.; Hüyük, T.; Jolie, J.; Judson, D. S.; Jungclaus, A.; Knoebel, R.; Kojouharov, I.; Korichi, A.; Korten, W.; Kurz, N.; Labiche, M.; Lalović, N.; Louchart-Henning, C.; Mengoni, D.; Merchán, E.; Million, B.; Morales, A. I.; Napoli, D.; Naqvi, F.; Nyberg, J.; Pietralla, N.; Podolyák, Zs.; Pullia, A.; Prochazka, A.; Quintana, B.; Rainovski, G.; Reese, M.; Recchia, F.; Reiter, P.; Rudolph, D.; Salsac, M. D.; Sanchis, E.; Sarmiento, L. G.; Schaffner, H.; Scheidenberger, C.; Sengele, L.; Singh, B. S. Nara; Singh, P. P.; Stahl, C.; Stezowski, O.; Thoele, P.; Valiente Dobon, J. J.; Weick, H.; Wendt, A.; Wieland, O.; Winfield, J. S.; Wollersheim, H. J.; Zielinska, M.; PreSPEC Collaboration

    2017-03-01

    Background: In the neutron-rich A ≈100 mass region, rapid shape changes as a function of nucleon number as well as coexistence of prolate, oblate, and triaxial shapes are predicted by various theoretical models. Lifetime measurements of excited levels in the molybdenum isotopes allow the determination of transitional quadrupole moments, which in turn provides structural information regarding the predicted shape change. Purpose: The present paper reports on the experimental setup, the method that allowed one to measure the lifetimes of excited states in even-even molybdenum isotopes from mass A =100 up to mass A =108 , and the results that were obtained. Method: The isotopes of interest were populated by secondary knock-out reaction of neutron-rich nuclei separated and identified by the GSI fragment separator at relativistic beam energies and detected by the sensitive PreSPEC-AGATA experimental setup. The latter included the Lund-York-Cologne calorimeter for identification, tracking, and velocity measurement of ejectiles, and AGATA, an array of position sensitive segmented HPGe detectors, used to determine the interaction positions of the γ ray enabling a precise Doppler correction. The lifetimes were determined with a relativistic version of the Doppler-shift-attenuation method using the systematic shift of the energy after Doppler correction of a γ -ray transition with a known energy. This relativistic Doppler-shift-attenuation method allowed the determination of mean lifetimes from 2 to 250 ps. Results: Even-even molybdenum isotopes from mass A =100 to A =108 were studied. The decays of the low-lying states in the ground-state band were observed. In particular, two mean lifetimes were measured for the first time: τ =29 .7-9.1+11.3 ps for the 4+ state of 108Mo and τ =3 .2-0.7+0.7 ps for the 6+ state of 102Mo. Conclusions: The reduced transition strengths B (E 2 ) , calculated from lifetimes measured in this experiment, compared to beyond

  17. Radioactive beam EXperiments at ISOLDE : Coulomb excitation and neutron transfer reactions of exotic nuclei.

    CERN Multimedia

    Kugler, E; Ratzinger, U; Wenander, F J C

    2002-01-01

    % IS347 \\\\ \\\\We propose to perform a pilot experiment to study very neutron rich (A<32) Na-Mg and (A<52) K-Ca isotopes in the region around the neutron shell closures of N=20 and N=28 after Coulomb excitation and neutron transfer, and to demonstrate highly efficient and cost-effective ways to bunch, charge-state breed and accelerate already existing mass-separated singly-charged radioactive ion beams. \\\\ \\\\To do this we plan to accelerate the ISOLDE beams up to 2~MeV/u by means of a novel acceleration scheme and to install an efficient $\\gamma$-ray array for low-multiplicity events around the target position.

  18. Radioactive ion exchange resin pretreatment and treatment system and corresponding process. Systemes de pre-traitement et de traitement de resines echangeuses d'ions radioactives et procede de traitement correspondant

    Energy Technology Data Exchange (ETDEWEB)

    Cochet, G.; Ranc, R.

    1989-05-12

    Spent organic ion exchange resins contain Li (cationic resins) and B (amionic resins) which interfere with cement after encapsulation. Radioactive anionic and cationic resins or their mixture are treated by a soluble aluminum salt for precipitation of insoluble lithium aluminate, then neutralized and mixed with the cement containing calcium oxide for precipitation of boron.

  19. Purification of radioactive decontamination liquids from NPP Paks with reactive adsorption and ion-exchange process

    Energy Technology Data Exchange (ETDEWEB)

    Szaanya, T.; Hanaak, L.; Marton, Gy.; Salamon, T. [University of Veszprem, Veszprem (Hungary); Tilky, P. [Nuclear Power Plant, Paks (Hungary)

    1999-07-01

    In nuclear power plant Paks, Hungary, alkaline oxidative (NaOH, KMnO{sub 4}, H{sub 2}O) and acidic reductive (citric- and oxalic acid, water) liquids are using for the decontamination of primary circuit equipment (main liquid circulating pumps, steam generators, pipelines etc). The above mentioned decontamination liquids are containing {sup 110m}Ag, {sup 95}Nb, {sup 54}Mn, {sup 58} Co, {sup 60}Co, {sup 51} Cr, {sup 124} Sb radioisotopes, summarized radioactivity is between 10{sup 3}-8x10{sup 4} kBq/dm{sup 3} liquid. The decontamination liquid can be cleaned with reactive adsorption (active carbon) and ion-exchange process at elevated temperature (333-368 K) in multilayered columns. After purification the summarized radioactivity for {sup 54}Mn, {sup 60}Co, and {sup 110m}Ag are in the outlet liquid below 1 kBq/dm{sup 3}. Decontamination factor DF{approx_equal}10{sup 3}-10{sup 4}, volumetric reduction factor VRF{approx_equal}50-500.

  20. A Monte Carlo code to optimize the production of Radioactive Ion Beams by the ISOL technique

    CERN Document Server

    Santana-Leitner, M

    2005-01-01

    Currently the nuclear chart includes around 3000 nuclides, distributed as ${\\beta}^+$, ${\\beta}^-$ and $\\alpha$-emitters, stable and spontaneously fissioning isotopes. A similar amount of unknown nuclei belongs to the so-called \\textit{terra incognita}, the uncertain region contained also within the proton, neutron and (fast) fission driplines and thereby stable against nucleon emission. The exploration of this zone is to be assisted by the use of radioactive ion beams (RIB) and could provide a new understanding of several nuclear properties. Moreover, besides pointing at crucial questions such as the validity of the shell model, the dilute matter and the halo structure, challenging experiments outside nuclear physics are also attended, e.g., explanations of the nucleosythesis processes that may justify why the matter in the universe has evolved to present proportions of elements, and which represents a major challenge to nuclear physics. These, together with other fascinating research lines in particle physi...

  1. Analysis methods of safe Coulomb-excitation experiments with radioactive ion beams using the GOSIA code

    Energy Technology Data Exchange (ETDEWEB)

    Zielinska, M. [CEA Saclay, IRFU/SPhN, Gif-sur-Yvette (France); Gaffney, L.P. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); University of the West of Scotland, School of Engineering, Paisley (United Kingdom); Wrzosek-Lipska, K. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Clement, E. [GANIL, Caen Cedex (France); Grahn, T.; Pakarinen, J. [University of Jyvaskylae, Department of Physics, Jyvaskylae (Finland); University of Helsinki, Helsinki Institute of Physics, Helsinki (Finland); Kesteloot, N. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); SCK-CEN, Belgian Nuclear Research Centre, Mol (Belgium); Napiorkowski, P. [University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Duppen, P. van [KU Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium); Warr, N. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany)

    2016-04-15

    With the recent advances in radioactive ion beam technology, Coulomb excitation at safe energies becomes an important experimental tool in nuclear-structure physics. The usefulness of the technique to extract key information on the electromagnetic properties of nuclei has been demonstrated since the 1960s with stable beam and target combinations. New challenges present themselves when studying exotic nuclei with this technique, including dealing with low statistics or number of data points, absolute and relative normalisation of the measured cross-sections and a lack of complementary experimental data, such as excited-state lifetimes and branching ratios. This paper addresses some of these common issues and presents analysis techniques to extract transition strengths and quadrupole moments utilising the least-squares fit code, GOSIA. (orig.)

  2. Beam Dynamics Design Studies of a Superconducting Radioactive Ion Beam Post-accelerator

    CERN Document Server

    Fraser, MA; Pasini, M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post- accelerated by the normal conducting REX linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of trans- verse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wa...

  3. Elastic scattering and total reaction cross sections with low-energy light radioactive ion beams.

    Directory of Open Access Journals (Sweden)

    Guimarães Valdir

    2011-10-01

    Full Text Available Elastic scattering experiments have being performed with low-energy radioactive ion beams produced by the RIBRAS facility in Sao Paulo, Brazil. Here I present the results for elastic scattering of 6He on several targets and light beams on 12C target. Special emphasis is given to the analysis of experiments were angular distributions for the elastic scattering of beryllium isotopes projectiles, 7Be, 9Be and 10Be, on a light target 12C were obtained. These elastic scattering angular distributions have been analysed in terms of optical model using the double-folding Sao Paulo potential. From this analysis, the total reaction cross section were also deduced and compared to the total reaction cross sections for many other light projectiles on 12C target. The comparison was made in terms of Universal Function reduction method.

  4. First Results From GRIFFIN: Half-Lives of Neutron Rich 128-130Cd

    Science.gov (United States)

    Dunlop, Ryan; Griffin Collaboration

    2016-09-01

    Half-lives of N = 82 nuclei below doubly-magic 132Sn are key input parameters for any astrophysical r-process scenario and play an important role in the formation and shape of the second r-process abundance peak. Shell-model calculations for neutron-rich nuclei near the N = 82 neutron shell closure that are not yet experimentally accessible have been performed by adjusting the quenching of the Gamow-Teller (GT) operator to reproduce the 130Cd half-life. The calculated half-lives of other nuclei in the region are known to be systematically too long. Recently, a shorter half-life for 130Cd was measured by the EURICA collaboration that resolves this discrepancy by scaling the GT quenching by a constant factor for all of the nuclei in the region. Distinguishing between these discrepant half-life measurements for 130Cd is thus of critical importance. We have measured the half-lives of 128-130Cd using the high-efficiency GRIFFIN γ-ray spectrometer at TRIUMF, which improves the precision of the 128,129Cd half-lives, and confirms the shorter half-life of 130Cd recently reported by the EURICA collaboration. Details of the GRIFFIN experiments will be presented and the implications of the resulting half-lives discussed.

  5. Symmetry energy and surface properties of neutron-rich exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gaidarov, M. K.; Antonov, A. N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Sarriguren, P. [Instituto de Estructura de la Materia, IEM-CSIC, Serrano 123, E-28006 Madrid (Spain); Moya de Guerra, E. [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain)

    2014-07-23

    The symmetry energy, the neutron pressure and the asymmetric compressibility of spherical Ni, Sn, and Pb and deformed Kr and Sm neutron-rich even-even nuclei are calculated within the coherent density fluctuation model using the symmetry energy as a function of density within the Brueckner energy-density functional. The correlation between the thickness of the neutron skin and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for isotopic chains of these nuclei in the framework of the deformed self-consistent mean-field Skyrme HF+BCS method. The mass dependence of the nuclear symmetry energy and the neutron skin thickness are also studied together with the role of the neutron-proton asymmetry. The studied correlations reveal a smoother behavior in the case of spherical nuclei than for deformed ones. We also notice that the neutron skin thickness obtained for {sup 208}Pb with SLy4 force is found to be in a good agreement with the recent data. In addition to the interest that this study may have by itself, we give some numerical arguments in proof of the existence of peculiarities of the studied quantities in Ni and Sn isotopic chains that are not present in the Pb chain.

  6. Investigation of reduced transition-strengths in neutron-rich chromium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Braunroth, Thomas; Dewald, Alfred; Fransen, Christoph; Litzinger, Julia [Institut fuer Kernphysik, Universitaet Koeln (Germany); Iwasaki, Hironori [National Superconducting Cyclotron Laboratory, MSU (United States); Lemasson, Antoine [GANIL, Laboratoire Commun DSM/CEA (France); Lenzi, Silvia [Department of Physics and Astronomy, University of Padova (Italy); INFN, Sezione di Padova (Italy)

    2015-07-01

    Neutron-rich nuclei close to N=40 are known for their rapid changes in nuclear structure. While {sup 68}Ni exhibits signatures of a shell closure, experimental data - e.g. excitation energies of the 2{sup +}{sub 1}-state and B(E2;2{sup +}{sub 1} → 0{sup +}{sub 1})-values - along the isotopic chains in even more exotic Fe and Cr-isotopes suggest a sudden rise in collective behaviour for N → 40. Lifetimes of low-lying yrast states in {sup 58,60,62}Cr were measured with the Recoil Distance Doppler-shift (RDDS) technique at NSCL, MSU (USA) to deduce model independent B(E2)-values. After fragmentation of a primary {sup 82}Se beam (E=140 AMeV) on a {sup 9}Be target and subsequent filtering with the A1900 fragment separator, high purity {sup 59,61,63}Mn-beams (E ∝ 95 AMeV) impinged on the {sup 9}Be plunger target, where excited states in the above mentioned Cr-isotopes were then populated in one proton knockout reactions. The S800 spectrograph allowed a clear recoil identification, which then lead to clean γ-spectra as measured by the Segmented Germanium Array (SeGA). Final results of this experiment will be shown and discussed in the context of state-of-the-art shell-model calculations.

  7. Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers

    Science.gov (United States)

    Wraith, C.; Yang, X. F.; Xie, L.; Babcock, C.; Bieroń, J.; Billowes, J.; Bissell, M. L.; Blaum, K.; Cheal, B.; Filippin, L.; Garcia Ruiz, R. F.; Gins, W.; Grob, L. K.; Gaigalas, G.; Godefroid, M.; Gorges, C.; Heylen, H.; Honma, M.; Jönsson, P.; Kaufmann, S.; Kowalska, M.; Krämer, J.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Nowacki, F.; Otsuka, T.; Papuga, J.; Sánchez, R.; Tsunoda, Y.; Yordanov, D. T.

    2017-08-01

    Collinear laser spectroscopy was performed on Zn (Z = 30) isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N = 33- 49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N = 50. Exactly one long-lived (>10 ms) isomeric state has been established in each 69-79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell-model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ = 1 /2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction. The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N = 43, while the progression towards 79Zn points to the stability of the Z = 28 and N = 50 shell gaps, supporting the magicity of 78Ni.

  8. Exotic neutron-rich medium-mass nuclei with realistic nuclear forces

    CERN Document Server

    Tsunoda, Naofumi; Shimizu, Noritaka; Hjorth-Jensen, Morten; Takayanagi, Kazuo; Suzuki, Toshio

    2016-01-01

    We present the first application of the newly developed theory of effective nucleon-nucleon interactions to the structure of exotic nuclei. This theory, a novel revision of many-body perturbation theory, enables us to perform shell-model calculations with several major shells ({\\it e.g.} $sd$+$pf$). Using the Entem-Machleidt QCD-based $\\chi\\mathrm{N}^3\\mathrm{LO}$ interaction and the Fujita-Miyazawa three-body force, exotic neutron-rich Ne, Mg and Si isotopes are studied systematically, with a good description of ground-state energies, 2$_1^+$ and 4$_1^+$ levels, and E2 transitions, as the first shell-model calculation for the "island of inversion" without two-body matrix elements fitted to experiment. The drip lines are predicted. We show effective single-particle energies from this interaction, exhibiting the shell evolution produced by the $\\chi\\mathrm{N}^3\\mathrm{LO}$ interaction + three-body force. The doubly-magic structure of ${}^{34}\\mathrm{Si}$ is demonstrated.

  9. Collective structural evolution in neutron-rich Yb, Hf, W, Os and Pt isotopes

    CERN Document Server

    Nomura, K; Rodriguez-Guzman, R; Robledo, L M; Sarriguren, P

    2011-01-01

    The low-lying quadrupole collective states in neutron-rich even-even Yb, Hf, W, Os, and Pt isotopes are studied in a systematic way. Spectroscopic calculations are performed in terms of the Interacting Boson Model Hamiltonian, which is determined from the Hartree-Fock-Bogoliubov (HFB) approach with Gogny Energy Density Functionals (EDFs). The multi-fermion dynamics of the surface deformation is simulated by the bosonic degrees of freedom so that the potential energy surface (PES) with quadrupole degrees of freedom, obtained from the constrained HFB calculations, is mapped onto the corresponding PES of the IBM system. The interaction strengths of the proton-neutron IBM (IBM-2) Hamiltonian are determined through this procedure, which enables one to access the spectroscopic properties. We demonstrate the occurrence of a prolate-to-oblate shape/phase transition as a function of neutron number in the considered isotope chains in both HFB (with D1S and D1M EDFs) and the corresponding mapped IBM PESs. The shape tran...

  10. Nuclear structure studies of the neutron-rich Rubidium isotopes using Coulomb excitation

    CERN Multimedia

    Reiter, P; Blazhev, A A; Voulot, D; Meot, V H; Simpson, G S; Georgiev, G P; Gaudefroy, L; Roig, O

    We propose to study the properties of odd-mass neutron-rich rubidium isotopes by the Coulomb-excitation technique, using the Miniball array coupled to the REX-ISOLDE facility. The results from similar measurements from the recent years (e.g. for the odd-mass and the odd-odd Cu isotopes, IS435) have shown the strong potential in such measurements for gaining information both for single-particle-like and collective states in exotic nuclei. Since there is practically no experimental information for excited states in the odd-mass Rb isotopes beyond $^{93}$Rb, the present study should be able to provide new data in a region of spherical ($^{93}$Rb and $^{95}$Rb) as well as well-deformed nuclei ($^{97}$Rb and $^{99}$Rb). Of particular interest is the rapid shape change that occurs when going from $^{95}$Rb (${\\varepsilon}_{2}$=0.06) to $^{97}$Rb (${\\varepsilon}_{2}$=0.3). These results should be of significant astrophysical interest as well, due to the close proximity of the r-process path.

  11. Decay studies and mass measurements on isobarically pure neutron-rich Hg and Tl isotopes

    CERN Multimedia

    Schweikhard, L C; Savreux, R P; Hager, U D K; Beck, D; Blaum, K

    2007-01-01

    We propose to perform mass measurements followed by $\\beta$- and $\\gamma$-decay studies on isobarically pure beams of neutron-rich Hg and Tl isotopes, which are very poorly known due to a large contamination at ISOL-facilities with surface-ionised francium. The aim is to study the binding energies of mother Hg and Tl nuclides, as well as the energies, spins and parities of the excited and ground states in the daughter Tl and Pb isotopes. The proposed studies will address a new subsection of the nuclear chart, with Z 126, where only 9 nuclides have been observed so far. Our studies will provide valuable input for mass models and shell-model calculations: they will probe the proton hole-neutron interaction and will allow to refine the matrix elements for the two-body residual interaction. Furthermore, they also give prospects for discovering new isomeric states or even new isotopes, for which the half-lives are predicted in the minute- and second-range.\\\\ To reach the isobaric purity, the experiments will be p...

  12. β-decay spectroscopy of neutron-rich 160,161,162Sm isotopes

    Science.gov (United States)

    Patel, Z.; Podolyák, Zs.; Walker, P. M.; Regan, P. H.; Söderström, P.-A.; Watanabe, H.; Ideguchi, E.; Simpson, G. S.; Nishimura, S.; Browne, F.; Doornenbal, P.; Lorusso, G.; Rice, S.; Sinclair, L.; Sumikama, T.; Wu, J.; Xu, Z. Y.; Aoi, N.; Baba, H.; Bello Garrote, F. L.; Benzoni, G.; Daido, R.; Dombrádi, Zs.; Fang, Y.; Fukuda, N.; Gey, G.; Go, S.; Gottardo, A.; Inabe, N.; Isobe, T.; Kameda, D.; Kobayashi, K.; Kobayashi, M.; Komatsubara, T.; Kojouharov, I.; Kubo, T.; Kurz, N.; Kuti, I.; Li, Z.; Liu, H. L.; Matsushita, M.; Michimasa, S.; Moon, C.-B.; Nishizuka, H.; Nishizuka, I.; Odahara, A.; Şahin, E.; Sakurai, H.; Schaffner, H.; Suzuki, H.; Takeda, H.; Tanaka, M.; Taprogge, J.; Vajta, Zs.; Xu, F. R.; Yagi, A.; Yokoyama, R.

    2016-09-01

    Neutron-rich 160,161,162Sm isotopes have been populated at the RIBF, RIKEN via β first time. β-coincident γ rays were observed in all three isotopes including γ rays from the isomeric decay of 160Sm and 162Sm. The isomers in 160Sm and 162Sm have previously been observed but have been populated via β decay for the first time. The isomeric state in 162Sm is assigned a {4^ - }v{{7 over 2}^ + }≤ft[ {633} right] otimes v{{1 over 2}^ - }≤ft[ {521} right] configuration based on the decay pattern. The level schemes of 160Sm and 162Sm are presented. The ground states in the parent nuclei 160Pm and 162Pm are both assigned a {6^ - }v{{7 over 2}^ + }≤ft[ {633} right] otimes π {{5 over 2}^ - }≤ft[ {532} right] configuration based on the population of states in the daughter nuclei. Blocked BCS calculations were performed to further investigate the spin-parities of the ground states in 160Pm, 161Pm, and 162Pm, and the isomeric state in 162Sm

  13. Beta-decay studies of neutron-rich Sc-Cr nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Gaudefroy, L.; Sorlin, O.; Donzaud, C.; Azaiez, F.; Bourgeois, C.; Chiste, V.; Guillemaud-Mueller, D.; Ibrahim, F.; Pougheon, F.; Stanoiu, M. [IN2P3-CNRS, Institut de Physique Nucleaire, Orsay Cedex (France); Angelique, J.C.; Grevy, S. [LPC, ISMRA, Caen Cedex (France); Dlouhy, Z.; Mrasek, J. [AS CR, Nuclear Physics Institute, Rez (Czech Republic); Kratz, K.-L.; Pfeiffer, B. [Universitaet Mainz, Institut fuer Kernchemie, Mainz (Germany); Lewitowicz, M.; Matea, I.; De Oliveira Santos, F.; Saint-Laurent, M.G. [GANIL, B.P. 5027, Caen Cedex (France); Lukyanov, S.M. [FLNR, JINR, Dubna, Moscow region (Russian Federation); Nowacki, F.; Penionzhkevich, Yu.-E. [Universite Louis Pasteur, IReS, IN2P3-CNRS, BP 28, Strasbourg Cedex (France)

    2005-01-01

    The neutron-rich nuclei{sup 57,58}{sub 21}Sc,{sup 58-60}{sub 22}Ti,{sup 60-63}{sub 23}V,{sup 62-66}{sub 24}Cr have been produced at Ganil via interactions of a 61.8A MeV {sup 76}Ge beam with a {sup 58}Ni target. Beta-decay studies have been performed using combined {beta}- and {gamma}-ray spectroscopy. Half-lives have been determined and {beta}-decay schemes are proposed for {sup 58}Ti, {sup 61}V and {sup 62}Cr. From these studies, new hints for the existence of {beta}-decaying isomers in {sup 60}V and in {sup 62}Mn are provided. These results are compared to shell model calculations. The role of the {pi}f{sub 7/2}- {nu}f{sub 5/2} proton-neutron interaction is examined through its influence on the lifetime values. (orig.)

  14. Direct Evidence of Octupole Deformation in Neutron-Rich $^{144}$Ba

    CERN Document Server

    Bucher, B; Wu, C Y; Janssens, R V F; Cline, D; Hayes, A B; Albers, M; Ayangeakaa, A D; Butler, P A; Campbell, C M; Carpenter, M P; Chiara, C J; Clark, J A; Crawford, H L; Cromaz, M; David, H M; Dickerson, C; Gregor, E T; Harker, J; Hoffman, C R; Kay, B P; Kondev, F G; Korichi, A; Lauritsen, T; Macchiavelli, A O; Pardo, R C; Richard, A; Riley, M A; Savard, G; Scheck, M; Seweryniak, D; Smith, M K; Vondrasek, R; Wiens, A

    2016-01-01

    The neutron-rich nucleus $^{144}$Ba ($t_{1/2}$=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers $A$ less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced $E1$ transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multi-step Coulomb excitation of a post-accelerated 650-MeV $^{144}$Ba beam on a 1.0-mg/cm$^2$ $^{208}$Pb target. The measured value of the matrix element, $\\langle 3_1^- \\| \\mathcal{M}(E3) \\| 0_1^+ \\rangle=0.65(^{+17}_{-23})$ $e$b$^{3/2}$, corresponds to a reduced $B(E3)$ transition probability of 48($^{+25}_{-34}$) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.

  15. Neutron-rich polonium isotopes studied with in-source laser spectroscopy

    CERN Document Server

    Dexters, Wim; Cocolios, T E

    This work studies the unknown region of neutron rich polonium isotopes. The polonium isotopes, with Z=84, lie above the magic lead nuclei (Z=82). The motivation for this research can mainly be found in these lead nuclei. When looking at the changes in the mean square charge radii beyond the N=126 shell gap, a kink is observed. This kink is also found in the radon (Z=86) and radium (Z=88) isotopes. The observed effect cannot be reproduced with our current models. The polonium isotopes yield more information on the kink and they are also able to link the known charge radii in lead isotopes to those in radon and radium. Additionally, the nuclear moments of the odd-neutron isotope $^{211}$Po are investigated. This nucleus has two protons and one neutron more than the doubly magic nucleus $^{208}$Pb. Nuclear moments of isotopes close to this doubly magic nucleus are good tests for the theoretic models. Besides pushing the models to their limits, the nuclear moments of $^{211}$Po also yield new information on the f...

  16. Coulomb excitation of neutron-rich odd-$A$ Cd isotopes

    CERN Multimedia

    Reiter, P; Kruecken, R; Gernhaeuser, R A; Kroell, T; Leske, J; Marginean, N M

    We propose to study excited states in the odd-${A}$ isotopes $^{123,125,127}$Cd by ${\\gamma}$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to determine the B(E2) values connecting excited states with the ground state as well as the long-lived (11/2$^{-}$) isomer. The proposed study profits from the unique capability of ISOLDE to produce beams containing Cd in the ground state or in the isomeric state. Our recent results on the neutron-rich even-A Cd nuclei appear to show that these nuclei may possess some collectivity beyond that calculated by modern shell-model predictions. Beyond-mean-field calculations also predict these nuclei to be weakly deformed. These facets are surprising considering their proximity to the doubly magic $^{132}$Sn. Coulomb-excitation studies of odd-${A}$ Cd isotopes may give a unique insight into the deformation-driving roles played by different orbits in this region. Such studies of the onset of collectivity become especially important in light of recent...

  17. Evolution of Single Particle and Collective properties in the Neutron-Rich Mg Isotopes

    CERN Multimedia

    Reiter, P; Wiens, A; Fitting, J; Lauer, M; Van duppen, P L E; Finke, F

    2002-01-01

    We propose to study the single particle and collective properties of the neutron-rich Mg isotopes in transfer reactions and Coulomb excitation using REX-ISOLDE and MINIBALL. From the Coulomb excitation measurement precise and largely model independent B( E2 ; 0$^{+}_{g.s.}\\rightarrow$ 2$^{+}_{1}$ ) will be determined for the even-even isotopes. For the odd isotopes the distribution of the E2 strength over a few low-lying states will be measured. The sign of the M1/E2 mixing ratio, extracted from angular distributions, is characteristic of the sign of the deformation, as is the resulting level scheme. The neutron-pickup channel in the transfer reactions will allow for a determination of the single particle properties (spin, parity, spectroscopic factors) of these nuclei. This information will give new insights in changes of nuclear structure in the vicinity of the island of deformation around $^{32}$Mg. A total of 24 shifts of REX beam time is requested.

  18. Low-lying dipole resonance in neutron-rich Ne isotopes

    Science.gov (United States)

    Yoshida, Kenichi; van Giai, Nguyen

    2008-07-01

    Microscopic structure of the low-lying isovector dipole excitation mode in neutron-rich Ne26,28,30 is investigated by performing deformed quasiparticle-random-phase-approximation (QRPA) calculations. The particle-hole residual interaction is derived from a Skyrme force through a Landau-Migdal approximation. We obtain the low-lying resonance in Ne26 at around 8.6 MeV. It is found that the isovector dipole strength at ExThomas-Reiche-Kuhn dipole sum rule. This excitation mode is composed of several QRPA eigenmodes, one is generated by a ν(2s1/2-12p3/2) transition dominantly and the other mostly by a ν(2s1/2-12p1/2) transition. The neutron excitations take place outside of the nuclear surface reflecting the spatially extended structure of the 2s1/2 wave function. In Ne30, the deformation splitting of the giant resonance is large, and the low-lying resonance overlaps with the giant resonance.

  19. Pygmy dipole mode in deformed neutron-rich Mg isotopes close to the drip line

    Science.gov (United States)

    Yoshida, Kenichi

    2009-10-01

    We investigate the microscopic structure of the low-lying isovector-dipole excitation mode in neutron-rich Mg36,38,40 close to the drip line by means of the deformed quasiparticle random-phase approximation employing the Skyrme and the local pairing energy-density functionals. It is found that the low-lying bump structure above the neutron emission-threshold energy develops when the drip line is approached, and that the isovector dipole strength at ExThomas-Reiche-Kuhn dipole sum rule in Mg40. We obtained the collective dipole modes at around 8-10 MeV in Mg isotopes, that consist of many two-quasiparticle excitations of the neutron. The transition density clearly shows an oscillation of the neutron skin against the isoscalar core. We found significant coupling effects between the dipole and octupole excitation modes due to the nuclear deformation. It is also found that the responses for the compressional dipole and isoscalar octupole excitations are much enhanced in the lower energy region.

  20. Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers

    Directory of Open Access Journals (Sweden)

    C. Wraith

    2017-08-01

    Full Text Available Collinear laser spectroscopy was performed on Zn (Z=30 isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N=33–49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N=50. Exactly one long-lived (>10 ms isomeric state has been established in each 69–79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell–model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ=1/2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction. The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N=43, while the progression towards 79Zn points to the stability of the Z=28 and N=50 shell gaps, supporting the magicity of 78Ni.

  1. High-Spin Structure in Neutron-Rich 108Ru Nucleus

    Institute of Scientific and Technical Information of China (English)

    CHE Xing-Lai; J. O. Rasmussen; Y. X. Luo; W. C. Ma; ZHU Sheng-Jiang; J.H Hamilton; A.V.Ramayya; J.K.Hwang; U Yong-Nam; LI Ming-Liang; ZHENG Rang-Chen; I.Y.Lee

    2004-01-01

    High spin states in the neutron-rich 108Ru nucleus have been studied through measuring prompt γγ-ray coincidences following the spontaneous fission of 252Cf with the Gammasphere detector array. The yrast band has been confirmed. The one-phonon γ-vibrational band and the two-quasiparticle band based on the 5- level have been extended up to 13+ and 15-, respectively. In addition, two levels at 1644.8kev and 1826.5kev excitation energies are newly identified and proposed to be the members of a two-phonon γ-vibrational band. It is shown that the 108Ru nucleus has triaxial deformation with parametersβ2 ~ 0.29 and γγ = -22° from the total Routhian surface calculations. The observed band crossing in the yrast band is due to the alignment of a pair of h11/2 neutrons according to the cranked shell model calculations. The possible configuration for the two-quasiparticle band has been discussed.

  2. Isomer-delayed gamma-ray spectroscopy of neutron-rich 166Tb

    Science.gov (United States)

    Gurgi, L. A.; Regan, P. H.; Söderström, P.-A.; Watanabe, H.; Walker, P. M.; Podolyák, Zs.; Nishimura, S.; Berry, T. A.; Doornenbal, P.; Lorusso, G.; Isobe, T.; Baba, H.; Xu, Z. Y.; Sakurai, H.; Sumikama, T.; Catford, W. N.; Bruce, A. M.; Browne, F.; Lane, G. J.; Kondev, F. G.; Odahara, A.; Wu, J.; Liu, H. L.; Xu, F. R.; Korkulu, Z.; Lee, P.; Liu, J. J.; Phong, V. H.; Yagi, A.; Zhang, G. X.; Alharbi, T.; Carroll, R. J.; Chae, K. Y.; Dombradi, Zs.; Estrade, A.; Fukuda, N.; Griffin, C.; Ideguchi, E.; Inabe, N.; Kanaoka, H.; Kojouharov, I.; Kubo, T.; Kubono, S.; Kurz, N.; Kuti, I.; Lalkovski, S.; Lee, E. J.; Lee, C. S.; Lotay, G.; Moon, C. B.; Nishizuka, I.; Nita, C. R.; Patel, Z.; Roberts, O. J.; Schaffner, H.; Shand, C. M.; Suzuki, H.; Takeda, H.; Terashima, S.; Vajta, Zs.; Kanaya, S.; Valiente-Dobòn, J. J.

    2017-09-01

    This short paper presents the identification of a metastable, isomeric-state decay in the neutron-rich odd-odd, prolate-deformed nucleus 166Tb. The nucleus of interest was formed using the in-flight fission of a 345 MeV per nucleon 238U primary beam at the RIBF facility, RIKEN, Japan. Gamma-ray transitions decaying from the observed isomeric states in 166Tb were identified using the EURICA gamma-ray spectrometer, positioned at the final focus of the BigRIPS fragments separator. The current work identifies a single discrete gamma-ray transition of energy 119 keV which de-excites an isomeric state in 166Tb with a measured half-life of 3.5(4) μs. The multipolarity assignment for this transition is an electric dipole and is made on the basis internal conversion and decay lifetime arguments. Possible two quasi-particle Nilsson configurations for the initial and final states which are linked by this transition in 166Tb are made on the basis of comparison with Blocked BCS Nilsson calculations, with the predicted ground state configuration for this nucleus arising from the coupling of the v(1-/2)?[521] and ? π(3+/2) Nilsson orbitals.

  3. β-decay spectroscopy of neutron-rich 160,161,162Sm isotopes

    Directory of Open Access Journals (Sweden)

    Patel Z.

    2016-01-01

    Full Text Available Neutron-rich 160,161,162Sm isotopes have been populated at the RIBF, RIKEN via β first time. β-coincident γ rays were observed in all three isotopes including γ rays from the isomeric decay of 160Sm and 162Sm. The isomers in 160Sm and 162Sm have previously been observed but have been populated via β decay for the first time. The isomeric state in 162Sm is assigned a 4−v72+[ 633 ]⊗v12−[ 521 ]${4^ - }v{{7 \\over 2}^ + }\\left[ {633} \\right] \\otimes v{{1 \\over 2}^ - }\\left[ {521} \\right]$ configuration based on the decay pattern. The level schemes of 160Sm and 162Sm are presented. The ground states in the parent nuclei 160Pm and 162Pm are both assigned a 6−v72+[633]⊗π52−[532]${6^ - }v{{7 \\over 2}^ + }\\left[ {633} \\right] \\otimes \\pi {{5 \\over 2}^ - }\\left[ {532} \\right]$ configuration based on the population of states in the daughter nuclei. Blocked BCS calculations were performed to further investigate the spin-parities of the ground states in 160Pm, 161Pm, and 162Pm, and the isomeric state in 162Sm

  4. Shape transitions in neutron-rich Ru isotopes: spectroscopy of 109,110,111,112Ru

    Energy Technology Data Exchange (ETDEWEB)

    Hua, H; Cline, D; Hayes, A B; Teng, R; Riley, D; Clark, R M; Fallon, P; Goergen, A; Macchiavelli, A O; Vetter, K

    2005-06-29

    The spectroscopy of neutron-rich {sup 109,110,111,112}Ru nuclei was studied by measuring the prompt {gamma} rays originated from fission fragments, produced by the {sup 238}U({alpha},f) fusion-fission reaction, in coincidence with the detection of both fragments. For {sup 109,111}Ru, both the negative-parity (h{sub 11/2} orbitals) and positive-parity (g{sub 7/2} and/or d{sub 5/2} orbitals) bands were extended to substantially higher spin and excitation energy than known previously. The ground-state and {gamma}-vibrational bands of {sup 110,112}Ru also were extended to higher spin, allowing observation of the second band crossing at the rotational frequency of {approx}450 keV in {sup 112}Ru, which is {approx}50 keV above the first band crossing. At a similar rotational frequency, the first band crossing for the h{sub 11/2} band in {sup 111}Ru was observed, which is absent in {sup 109}Ru. These band crossings most likely are caused by the alignment of the g{sub 9/2} proton pair. This early onset of the band crossing for the aligned {pi}g{sub 9/2} orbitals may be evidence of a triaxial shape transition from prolate to oblate occurring in {sup 111}Ru. The data together with a comparison of cranked shell model predictions are presented.

  5. Measurement of the dipole response of neutron-rich nuclei in the A approx 20 region

    CERN Document Server

    Datta-Pramanik, U; Leistenschneider, A; Boretzky, K; Cortina-Gil, D; Elze, T W; Emling, H; Geissel, H; Grünschloss, A; Hellström, M; Holzmann, R; Ilievski, S; Iwasa, N; Kratz, J V; Kulessa, R; Leifels, Y; Lubkiewicz, E; Münzenberg, G; Reiter, P; Rejmund, M; Scheidenberger, C; Schlegel, C; Simon, H; Stroth, J; Sümmerer, K; Wajda, E; Walús, W

    2002-01-01

    Coulomb break up of the neutron-rich sup 1 sup 5 sup , sup 1 sup 7 C and sup 1 sup 7 sup - sup 2 sup 2 O isotopes has been studied experimentally using secondary beams at energies of 500-600 MeV/u. A comparison between differential cross sections, d sigma/dE sup * , with that obtained from a binary model shows that the main ground-state configuration of sup 1 sup 5 C is sup 1 sup 4 C(0 sup +)centre dot nu sub S sub sub 1 sub sub / sub sub 2 as expected. For sup 1 sup 7 C, our preliminary data analysis reveals that the predominant (approx 64%) configuration of the ground state is sup 1 sup 6 C(2 sup +)centre dot nu sub s sub , sub d. For sup 1 sup 7 sup - sup 2 sup 2 O, the low-lying E1 strength amounts up to about 12% of the energy weighted sum rule strength depending on neutron number. The energy weighted E1 strength (integrated up to 15 MeV excitation energy) increases up to sup 2 sup 0 O then decreases for sup 2 sup 1 sup , sup 2 sup 2 O. These data are compared to a shell model calculation.

  6. Shape coexistence in neutron-rich Sr isotopes : Coulomb excitation of $^{96}$Sr

    CERN Multimedia

    Clement, E; Siem, S; Czosnyka, T

    2007-01-01

    The nuclei in the mass region A $\\cong$ 100 around Sr and Zr show a dramatic change of the nuclear ground-state shape from near spherical for N $\\leq$ 58 to strongly deformed for N $\\geq$ 60. Theoretical calculations predict the coexistence of slightly oblate and strongly prolate deformed configurations in the transitional region. However, excited rotational structures based on the highly deformed configuration, which becomes the ground state at N = 60, are not firmly established in the lighter isotopes, and the earlier interpretation of a very abrupt change of shape has been challenged by recent experimental results in favor of a rather gradual change. We propose to study the electromagnetic properties of the neutron-rich nucleus $_{38}^{96}$Sr$_{58}$ by low-energy Coulomb excitation using the REX-ISOLDE facility and the MINIBALL detector array. Both transitional and diagonal matrix elements will be extracted, resulting in a complete description of the transition strengths and quadrupole moments of the low-l...

  7. Advanced model for the prediction of the neutron-rich fission product yields

    Directory of Open Access Journals (Sweden)

    Rubchenya V. A.

    2013-12-01

    Full Text Available The consistent models for the description of the independent fission product formation cross sections in the spontaneous fission and in the neutron and proton induced fission at the energies up to 100 MeV is developed. This model is a combination of new version of the two-component exciton model and a time-dependent statistical model for fusion-fission process with inclusion of dynamical effects for accurate calculations of nucleon composition and excitation energy of the fissioning nucleus at the scission point. For each member of the compound nucleus ensemble at the scission point, the primary fission fragment characteristics: kinetic and excitation energies and their yields are calculated using the scission-point fission model with inclusion of the nuclear shell and pairing effects, and multimodal approach. The charge distribution of the primary fragment isobaric chains was considered as a result of the frozen quantal fluctuations of the isovector nuclear matter density at the scission point with the finite neck radius. Model parameters were obtained from the comparison of the predicted independent product fission yields with the experimental results and with the neutron-rich fission product data measured with a Penning trap at the Accelerator Laboratory of the University of Jyväskylä (JYFLTRAP.

  8. Microscopic description of fission in neutron-rich radium isotopes with the Gogny energy density functional

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Guzman, R. [Kuwait University, Physics Department, Kuwait (Kuwait); Robledo, L.M. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain)

    2016-01-15

    Mean-field calculations, based on the D1S, D1N and D1M parametrizations of the Gogny energy density functional, have been carried out to obtain the potential energy surfaces relevant to fission in several Ra isotopes with the neutron number 144 ≤ N ≤ 176. Inner and outer barrier heights as well as first and second isomer excitation energies are given. The existence of a well-developed third minimum along the fission paths of Ra nuclei is analyzed in terms of the energetics of the ''fragments'' defining such elongated configuration. The masses and charges of the fission fragments are studied as functions of the neutron number in the parent Ra isotope. The comparison between fission and α-decay half-lives, reveals that the former becomes faster for increasing neutron numbers. Though there exists a strong variance of the results with respect to the parameters used in the computation of the spontaneous fission rate, a change in tendency is observed at N = 164 with a steady increase that makes heavier neutron-rich Ra isotopes stable against fission, diminishing the importance of fission recycling in the r-process. (orig.)

  9. Precision mass measurements of neutron-rich yttrium and niobium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Hager, U. [Department of Physics, University of Jyvaeskylae, PO Box 35 (YFL), FIN-40014 (Finland)], E-mail: ulrike.hager@phys.jyu.fi; Jokinen, A.; Elomaa, V.-V.; Eronen, T.; Hakala, J.; Kankainen, A.; Rahaman, S.; Rissanen, J.; Moore, I.D.; Rinta-Antila, S.; Saastamoinen, A.; Sonoda, T.; Aystoe, J. [Department of Physics, University of Jyvaeskylae, PO Box 35 (YFL), FIN-40014 (Finland)

    2007-09-01

    The atomic masses of neutron-rich {sup 95-101}Y and {sup 101-107}Nb produced in proton-induced fission of uranium were determined using the JYFLTRAP double Penning trap setup. Accuracies of better than 10 keV could be reached for most nuclides. The masses of {sup 106,107}Nb were measured for the first time. The energies of the isomeric states in {sup 96}Y and {sup 100}Y were measured as 1541(10) keV and 145(15) keV. The niobium isotopes appear to be systematically less bound than the values given in the latest Atomic Mass Evaluation. The new data lie in a region of the nuclear chart characterised by the transition from spherical to strongly deformed shapes. These structural changes are explored by studying different systematic trends. The data are also compared to several model predictions to test their ability to reproduce the structural changes along the isotopic chains of yttrium and niobium.

  10. The neutron-rich oxygen isotopes {sup 25,26}O

    Energy Technology Data Exchange (ETDEWEB)

    Caesar, Christoph [TU Darmstadt, Institut fuer Kernphysik (Germany); Collaboration: R3B-Collaboration

    2014-07-01

    The R3B-collaboration has studied the neutron-rich oxygen isotopes {sup 25,26}O by utilizing a kinematically complete measurement at relativistic beam energies with the R3B-LAND-setup[1]. The isotopes of interest have been populated via proton removal from {sup 26,27}F, respectively. The ground-state masses of both isotopes have been extracted: E{sub r}({sup 25}O(gs)) = 725{sup +54}{sub -29} keV; E{sub r}({sup 26}O(gs)) ≤ 40/120 (68%/95% c.l.) keV. Furthermore, limits on the lifetime of both ground-states have been extracted for the first time: τ({sup 25}O(gs)) ≥ 8.2 x 10{sup -12} ns; τ({sup 26}O(gs)) ≤ 5.7 ns. The determined ground-state energies have been compared to theoretical shell-model calculations based on chiral effective field theory potentials using chiral NN and 3N forces. In addition residual three-valence-neutron forces, which become more important with increasing neutron number along isotopic chains are included.

  11. Decay Spectroscopy of Neutron-Rich Cd Around the N = 82 Shell Closure

    Science.gov (United States)

    Bernier, Nikita; Dillmann, Iris; Kruecken, Reiner; Griffin Collaboration

    2016-09-01

    The neutron-rich region around A = 132 is of special interest for nuclear astrophysics and nuclear structure. This region is connected with the second r-process abundance peak at A 130 and the waiting-point nuclei around N = 82. For nuclear structure studies, the neighbours of the doubly-magic 132Sn (Z = 50, N = 82) are an ideal test ground for shell model predictions. The beta-decay of the N = 82 isotope 130Cd into 130In was first investigated a decade ago, but the information for states of the lighter indium isotopes (128,129In) is still limited. In the present experiment, a detailed gamma-spectroscopy of the beta-decay of 128-132Cd was achieved with the newly commissioned GRIFFIN (Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei) gamma-ray spectrometer, which is capable of measuring down to rates of 0.1 pps. The low-energy cadmium isotopes were implanted into a movable tape at the central focus of the array from the ISAC-I facility at TRIUMF. The beta-tagging was performed using the auxiliary beta-particle detector SCEPTAR. The required beta-gamma(-gamma) coincidence data in high statistics needed to fill the spectroscopic gaps described in literature were obtained. The ongoing analysis of these data will be presented. Work supported by the Natural Sciences and Engineering Research Council of Canada and the National Research Council of Canada.

  12. Coulomb breakup of neutron-rich $^{29,30}$Na isotopes near the island of inversion

    CERN Document Server

    Rahaman, A; Aumann, T; Beceiro-Novo, S; Boretzky, K; Caesar, C; Carlson, B V; Catford, W N; Chakraborty, S; Chartier, M; Cortina-Gil, D; Angelis, G De; Gonzalez-Diaz, D; Emling, H; Fernandez, P Diaz; Fraile, L M; Ershova, O; Geissel, H; Jonson, B; Johansson, H; Kalantar-Nayestanaki, N; Krücken, R; Kröll, T; Kurcewicz, J; Langer, C; Bleis, T Le; Leifels, Y; Münzenberg, G; Marganiec, J; Nilsson, T; Nociforo, C; Nowacki, F; Najafi, A; Panin, V; Paschalis, S; Plag, R; Poves, A; Ray, I; Reifarth, R; Rigollet, C; Ricciardi, V; Rossi, D; Scheit, H; Simon, H; Scheidenberger, C; Typel, S; Taylor, J; Togano, Y; Volkov, V; Weick, H; Wagner, A; Wamers, F; Weigand, M; Winfield, J S; Yakorev, D; Zoric, M

    2016-01-01

    First results are reported on the ground state configurations of the neutron-rich $^{29,30}$Na isotopes, obtained via Coulomb dissociation (CD) measurements as a method of the direct probe. The invariant mass spectra of those nuclei have been obtained through measurement of the four-momentum of all decay products after Coulomb excitation on a $^{208}Pb$ target at energies of 400-430 MeV/nucleon using FRS-ALADIN-LAND setup at GSI, Darmstadt. Integrated Coulomb-dissociation cross-sections (CD) of 89 $(7)$ mb and 167 $(13)$ mb up to excitation energy of 10 MeV for one neutron removal from $^{29}$Na and $^{30}$Na respectively, have been extracted. The major part of one neutron removal, CD cross-sections of those nuclei populate core, in its' ground state. A comparison with the direct breakup model, suggests the predominant occupation of the valence neutron in the ground state of $^{29}$Na${(3/2^+)}$ and $^{30}$Na${(2^+)}$ is the $d$ orbital with small contribution in the $s$-orbital which are coupled with ground ...

  13. Shape coexistence in neutron-rich odd-mass S isotopes

    Science.gov (United States)

    Mijatovic, Tea; Kobayashi, Nobuyuki; Iwasaki, Hiro; Loelius, Charles; Whitmore, Kenneth; Elder, Robert; Gade, Alexandra; Bazin, Daniel; Weisshaar, Dirk; Bender, Peter; Belarge, Joe; Lunderberg, Eric; Elman, Brandon; Longfellow, Brenden; Dewald, Alfred; Haylett, Thoryn; Mathry, Michael; Heil, Sebastian

    2017-01-01

    Collective motions in atomic nuclei at low excitation energies have been characterized by the ground-state shape as a single basis. This picture can be altered in exotic nuclei with unusual proton-to-neutron ratios if the nuclear shape can change drastically at low spin. Recently, there has been an increasing interest for shape-coexistence phenomena in neutron-rich S isotopes and studies suggested fairly large collectivity in 40 , 42 , 44S isotopes. We will discuss the search for isomeric or long-lived states in 45S for which no excited states are known in the literature and the pursuit to fully characterize the band structure of the low-lying states in 43,45S, which provide key information to establish a comprehensive picture of the shape coexistence in this region. Direct model-independent measurements of the 43,45S excited states were realized by applying the Recoil Distance Method with the TRIPLEX Plunger in conjunction with GRETINA to fast rare isotope beams at the NSCL.

  14. Deformation in the neutron rich sulfur isotopes {sup 40}S and {sup 42}S

    Energy Technology Data Exchange (ETDEWEB)

    Glasmacher, T.; Scheit, H.; Brown, B.A. [Michigan State Univ., East Lansing, MI (United States)] [and others

    1996-12-31

    In the experiment described here radioactive beams of {sup 40,42}S and {sup 44,46}Ar (E{approx}40 MeV/nucl.) were produced in the A1200 fragment separator at the National Superconducting Cyclotron Laboratory at Michigan State University by fragmenting an 80 MeV/nucleon {sup 48}Ca{sup 13+} beam in a 379 mg/cm{sup 2} {sup 9}Be target. The exotic ions were positively identified by a time of flight measurement before interacting with the secondary gold target (93.5 mg/cm{sup 2} or 184.1 mg/cm{sup 2}). After interacting with the virtual photon field in the gold target, fragments scattered into a lab angle of less than 4.1{degrees} were detected in a fast/slow plastic phoswich detector located downstream from the secondary target. The energy loss - total energy measurement allowed the rejection of events which led to the breakup of the projectile in the target. Photons from the deexcitation of the projectile were measured in coincidence with beam particles. The photons emitted from the excited projectile can be clearly distinguished from photons coming from the target by their Doppler shift and Doppler broadening.

  15. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    Directory of Open Access Journals (Sweden)

    M. A. Fraser

    2011-02-01

    Full Text Available The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wave resonator and the asymmetry of the rf defocusing forces in the solenoid focusing channel. A racetrack shaped beam port aperture was shown to improve the symmetry of the fields in the high-β quarter-wave resonator and reduce the loss of acceptance under the offset used to compensate the steering force. The methods used to compensate the beam steering are described and an optimization routine written to minimize the steering effect when all cavities of a given family are offset by the same amount, taking into account the different velocity profiles across the range of mass-to-charge states accepted. The assumptions made in the routine were shown to be adequate and the results well correlated with the beam quality simulated in multiparticle beam dynamics simulations. The specification of the design tolerances is outlined based on studies of the sensitivity of the beam to misalignment and errors, with particular

  16. First on-line mass measurements at SHIPTRAP and mass determinations of neutron-rich Fr and Ra isotopes at ISOLTRAP

    CERN Document Server

    Rahaman, Saidu

    SHIPTRAP is an ion trap facility behind the velocity filter SHIP at GSI/Darmstadt. Its aim are precision studies of transuranium nuclides produced in a fusion reaction and separated by SHIP. The current set-up for high-precision mass measurements consists of three main functional parts: (i) a gas cell for stopping the energetic ions from SHIP, (ii) radiofrequency quadrupole structures to cool and to bunch the ions extracted from the gas cell, and (iii) a superconducting magnet with two cylindrical Penning traps at a field strength of 7 T. In this work the Penning trap system has been installed and extensively characterized. The first on-line mass measurements of short-lived nuclides were carried out and the masses of $^{147}$Er and $^{148}$Er could be experimentally determined for the first time. Here a relative mass uncertainty of $\\delta$ m/m of about 1$\\times$ 10$^{-6}$ was achieved. Furthermore the masses of heavy neutron-rich $^{229-232}$Ra and $^{230}$Fr isotopes have been determined with a relative m...

  17. Nuclear reactions with 11C and 14O radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Fanqing

    2004-12-09

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F were fitted with an R-matrix calculation. Spins and parities were assigned to the two observed resonances. This new measurement of the 15F ground state supports the disappearance of the Z

  18. SHyPIE: a new source for on-line production of multicharged radioactive condensable ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Lecesne, N.; Foury, P.; Gaubert, G.; Huguet, Y.; Jardin, P.; Leroy, R.; Lewitowicz, M.; Marry, C.; Maunoury, L.; Pacquet, J.Y.; Robert, E.; Saint-Laurent, M.G.; Seron, D.; Sortais, P.; Villari, A.C.C. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France); Angelique, J.C.; Orr, N.A. [Laboratoire de Physique Corpusculaire (CNRS/IN2P3), ISMRA, 14 - Caen (France); Blank, B. [CENBG, Centre d' Etudes Nucleaires de Bordeaux Gradignan, 33 (France); Clapier, F.; Ducourtieux, M.; Kandri-Rody, S.; Obert, J.; Pauwels, N.; Proust, J.; Putaux, J.C. [Institut de Physique Nucleaire, (IN2P3/CNRS) 91 - Orsay (France); Lepine, A. [IFUSP, C.P., Sao Paulo (Brazil)

    1999-07-01

    In order to define the future intensity and reliability of the on line radioactive beams for the SPIRAL project, an intense activity of research and development is being done around the target and the ion source problems. The main instrument for this purpose is the isotopic separator SIRa (Separateur d'Ions Radioactifs) installed in the D2 experimental cave at GANIL. One of the research axis is the production of multicharged radioactive condensable ions. In this aim, we have built a new compact ECR ion source, SHyPIE (Source Hybride pour la Production d'Ions Exotiques), whose original magnetic configuration is under patent since 1997. This new magnetic structure allows to place an internal production target very close to the plasma, while avoiding radiation damages of the sensitive permanent magnets. A series of on line experiments have been done, using SHyPIE with several internal target systems, and around thirty species of condensable and noble gases radioactive multicharged ion beams have been produced. The behaviour of the plasma in a close geometry with the production target has been studied. (authors)

  19. Precision mass measurements on neutron-rich Zn isotopes and their consequences on the astrophysical r-process

    Energy Technology Data Exchange (ETDEWEB)

    Baruah, Sudarshan

    2008-07-15

    The rapid neutron-capture or the r-process is responsible for the origin of about half of the neutron-rich atomic nuclei in the universe heavier than iron. For the calculation of the abundances of those nuclei, atomic masses are required as one of the input parameters with very high precision. In the present work, the masses of the neutron rich Zn isotopes (A=71 to 81) lying in the r-process path have been measured in the ISOLTRAP experiment at ISOLDE/CERN. The mass of {sup 81}Zn has been measured directly for the rst time. The half-lives of the nuclides ranged from 46.5 h ({sup 72}Zn) down to 290 ms ({sup 81}Zn). In case of all the nuclides, the relative mass uncertainty ({delta}m=m) achieved was in the order of 10{sup -8} corresponding to a 100-fold improvement in precision over previous measurements. (orig.)

  20. Decay Study for the very Neutron-Rich Sn Nuclides, $^{135-140}$Sn Separated by Selective Laser Ionization

    CERN Multimedia

    2002-01-01

    %IS378 %title\\\\ \\\\ In this investigation, we wish to take advantage of chemically selective laser ionization to separate the very-neutron-rich Sn nuclides and determine their half-lives and delayed-neutron branches (P$_{n}$) using the Mainz $^{3}$He-delayed neutron spectrometer and close-geometry $\\gamma$-ray spectroscopy system. The $\\beta$-decay rates are dependent on a number of nuclear structure factors that may not be well described by models of nuclear structure developed for nuclides near stability. Determination of these decay properties will provide direct experimental data for r-process calculations and test the large number of models of nuclear structure for very-neutron rich Sn nuclides now in print.

  1. Charge-changing cross section measurement of neutron-rich carbon isotopes at 50 AMeV

    Directory of Open Access Journals (Sweden)

    Tran D.T.

    2016-01-01

    Full Text Available Charge Changing Cross Sections (CCCS or σCC of neutron-rich carbon isotopes on carbon target were measured at low energy (50A MeV for the first time. The consistency between Glauber calculation and experimental σCC of 12C isotope at low energy region shows that proton distribution radii can be derived from CCCS at low energy.

  2. Study of Neutron-Rich $^{124,126,128}$Cd Isotopes; Excursion from Symmetries to Shell-Model Picture

    CERN Multimedia

    Nieminen, A M; Reponen, M

    2002-01-01

    A short outline is given on a number of topics that are present in the long series of even-even Cd nuclei and therefore, may turn out to constitute an ideal test bench in order to verify a number of theoretical ideas on how collective motion, near closed shells, builds up taking into account both the valence and core nucleons when studying the nucleon correlations. Moreover, these experiments can reveal new challenges when moving towards very neutron-rich systems.

  3. The production of unknown neutron-rich isotopes in $^{238}$U+$^{238}$U collisions at near-barrier energy

    CERN Document Server

    Zhao, Kai; Zhang, Yingxun; Wang, Ning; Li, Qingfeng; Shen, Caiwan; Wang, Yongjia; Wu, Xizhen

    2016-01-01

    The production cross sections for primary and residual fragments with charge number from $Z$=70 to 120 produced in the collision of $^{238}$U+$^{238}$U at 7.0 MeV/nucleon are calculated by the improved quantum molecular dynamics (ImQMD) model incorporated with the statistical evaporation model (HIVAP code). The calculation results predict that about sixty unknown neutron-rich isotopes from element Ra ($Z$=88) to Db ($Z$=105) can be produced with the production cross sections above the lower bound of $10^{-8}$ mb in this reaction. And almost all of unknown neutron-rich isotopes are emitted at the laboratory angles $\\theta_{lab}\\leq$ 60$^\\circ$. Two cases, i.e. the production of the unknown uranium isotopes with $A\\geq$ 244 and that of rutherfordium with $A\\geq$ 269 are investigated for understanding the production mechanism of unknown neutron-rich isotopes. It is found that for the former case the collision time between two uranium nuclei is shorter and the primary fragments producing the residues have smaller...

  4. Study of chemically synthesized ZnO nano particles under a bio template using radioactive ion beam

    CERN Multimedia

    This is a project proposal to study nano sized semiconductor ZnO system, useful in biology and medicinal purposes, using radioactive ion beam from ISOLDE. Doping of the nano particles with Cu, Cd and Ga ions (in their variable valancy states) are expected to impart changes in the electrical structure and properties in the said system under study. The morphological changes, chemical environment, micro structure, electrical and optical properties of the nano size particles of ZnO system (developed under a bio template of folic acid) after the interaction with radioactive ion beam will be studied. The provision of perturbed angular correlation (PAC) study with respect to the changes in chemical environment, where ever possible will be attempted.

  5. Lifetimes in neutron-rich Nd isotopes measured by Doppler profile method

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Lister, C.J.; Morss, L.R. [and others

    1995-08-01

    Lifetimes of the rotational levels in neutron-rich even-even Nd isotopes were deduced from the analysis of the Doppler broadened line shapes. The experiment was performed at Daresbury with the Eurogam array, which at that time consisted of 45 Compton-suppressed Ge detectors and 5 Low-Energy Photon Spectrometers. The source was in the form of a 7-mm pellet which was prepared by mixing 5-mg; {sup 248}Cm and 65-mg KCl and pressing it under high pressure. Events for which three or more detectors fired were used to construct a cubic data array whose axes represented the {gamma}-ray energies and the contents of each channel the number of events with that particular combination of {gamma}-ray energies. From this cubic array, one-dimensional spectra were generated by placing gates on peaks on the other two axes. Gamma-ray spectra of even-even Nd isotopes were obtained by gating on the transitions in the complimentary Kr fragments. The gamma peaks de-exciting states with I {>=} 12 h were found to be broader than the instrumental line width due to the Doppler effect. The line shapes of they-ray peaks were fitted separately with a simple model for the feeding of the states and assuming a rotational band with constant intrinsic quadruple moment and these are shown in Fig. I-27. The quadrupole moments thus determined were found to be in good agreement with the quadrupole moments measured previously for lower spin states. Because of the success of this technique for the Nd isotopes, we intend to apply this technique to the new larger data set collected with the Eurogam II array. The results of this study were published.

  6. The impact of the intruder orbitals on the structure of neutron-rich Ag isotopes

    Science.gov (United States)

    Kim, Y. H.; Biswas, S.; Rejmund, M.; Navin, A.; Lemasson, A.; Bhattacharyya, S.; Caamaño, M.; Clément, E.; de France, G.; Jacquot, B.

    2017-09-01

    The low-lying high-spin yrast band structure of neutron-rich 113 , 118- 121Ag has been established for the first time using prompt γ-ray spectroscopy of isotopically identified fission fragments produced in the 9Be(238U, fγ) fusion- and transfer-induced fission processes. The newly obtained level energies follow the systematics of the neighboring isotopes. The sequences of levels exhibit an energy inheritance from states in the corresponding Cd core. A striking constancy of a large signature splitting in odd-A Ag throughout the long chain of isotopes with 50 < N < 82 and a signature inversion in even-A Ag isotopes, which are indications of triaxiality, were evidenced. These observed features were reproduced by large-scale shell-model calculations with a spherical basis for the first time in the Ag isotopic chain, revealing microscopically their complex nature with severely broken seniority ordering. The essential features of the observed signature splitting were further examined in the light of simplified, two-orbital shell-model calculations including only two intruder orbitals πg9/2 and νh11/2 from two consecutive shells above Z = 50 and N = 82 for protons and neutrons respectively, resulting in the πg9/2-3 × νh11/2m configurations. The newly established bands were understood as fairly pure, built mainly on unique-parity intruder configurations and coupled to the basic states of the Cd core.

  7. Antisymmetrized molecular dynamics studies for exotic clustering phenomena in neutron-rich nuclei

    Science.gov (United States)

    Kimura, M.; Suhara, T.; Kanada-En'yo, Y.

    2016-12-01

    We present a review of recent works on clustering phenomena in unstable nuclei studied by antisymmetrized molecular dynamics (AMD). The AMD studies in these decades have uncovered novel types of clustering phenomena brought about by the excess neutrons. Among them, this review focuses on the molecule-like structure of unstable nuclei. One of the earliest discussions on the clustering in unstable nuclei was made for neutron-rich Be and B isotopes. AMD calculations predicted that the ground state clustering is enhanced or reduced depending on the number of excess neutrons. Today, the experiments are confirming this prediction as the change of the proton radii. Behind this enhancement and reduction of the clustering, there are underlying shell effects called molecular and atomic orbits. These orbits form covalent and ionic bonding of the clusters analogous to the atomic molecules. It was found that this "molecular-orbit picture" reasonably explains the low-lying spectra of Be isotopes. The molecular-orbit picture is extended to other systems having parity asymmetric cluster cores and to the three cluster systems. O and Ne isotopes are the candidates of the former, while the 3 α linear chains in C isotopes are the latter. For both subjects, many intensive studies are now in progress. We also pay a special attention to the observables which are the fingerprint of the clustering. In particular, we focus on the monopole and dipole transitions which are recently regarded as good probe for the clustering. We discuss how they have and will reveal the exotic clustering.

  8. The impact of the intruder orbitals on the structure of neutron-rich Ag isotopes

    Directory of Open Access Journals (Sweden)

    Y.H. Kim

    2017-09-01

    Full Text Available The low-lying high-spin yrast band structure of neutron-rich 113,118–121Ag has been established for the first time using prompt γ-ray spectroscopy of isotopically identified fission fragments produced in the 9Be(238U, fγ fusion- and transfer-induced fission processes. The newly obtained level energies follow the systematics of the neighboring isotopes. The sequences of levels exhibit an energy inheritance from states in the corresponding Cd core. A striking constancy of a large signature splitting in odd-A Ag throughout the long chain of isotopes with 50

  9. Antisymmetrized molecular dynamics studies for exotic clustering phenomena in neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, M. [Hokkaido University, Department of Physics, Sapporo (Japan); Hokkaido University, Nuclear Reaction Data Centre, Faculty of Science, Sapporo (Japan); Suhara, T. [Matsue College of Technology, Matsue (Japan); Kanada-En' yo, Y. [Kyoto University, Department of Physics, Kyoto (Japan)

    2016-12-15

    We present a review of recent works on clustering phenomena in unstable nuclei studied by antisymmetrized molecular dynamics (AMD). The AMD studies in these decades have uncovered novel types of clustering phenomena brought about by the excess neutrons. Among them, this review focuses on the molecule-like structure of unstable nuclei. One of the earliest discussions on the clustering in unstable nuclei was made for neutron-rich Be and B isotopes. AMD calculations predicted that the ground state clustering is enhanced or reduced depending on the number of excess neutrons. Today, the experiments are confirming this prediction as the change of the proton radii. Behind this enhancement and reduction of the clustering, there are underlying shell effects called molecular and atomic orbits. These orbits form covalent and ionic bonding of the clusters analogous to the atomic molecules. It was found that this ''molecular-orbit picture'' reasonably explains the low-lying spectra of Be isotopes. The molecular-orbit picture is extended to other systems having parity asymmetric cluster cores and to the three cluster systems. O and Ne isotopes are the candidates of the former, while the 3α linear chains in C isotopes are the latter. For both subjects, many intensive studies are now in progress. We also pay a special attention to the observables which are the fingerprint of the clustering. In particular, we focus on the monopole and dipole transitions which are recently regarded as good probe for the clustering. We discuss how they have and will reveal the exotic clustering. (orig.)

  10. THE HYPHI PROJECT : HYPERNUCLEAR SPECTROSCOPY WITH STABLE HEAVY ION BEAMS AND RARE ISOTOPE BEAMS AT GSI AND FAIR

    NARCIS (Netherlands)

    Bianchin, S.; Achenbach, P.; Ajimura, S.; Borodina, O.; Fukuda, T.; Hoffmann, J.; Kavatsyuk, M.; Koch, K.; Koike, T.; Kurz, N.; Maas, F.; Minami, S.; Mizoi, Y.; Nagae, T.; Nakajima, D.; Okamura, A.; Ott, W.; Ozel, B.; Pochodzalla, J.; Rappold, C.; Saito, T. R.; Sakaguchi, A.; Sako, M.; Sekimoto, M.; Sugimura, H.; Takahashi, T.; Tamura, H.; Tanida, K.; Trautmann, W.

    2009-01-01

    The HypHI collaboration aims to perform a precise hypernuclear spectroscopy with stable heavy ion beams and rare isotope beams at GSI and FAIR in order to study hypernuclei at extreme isospin, especially neutron rich hypernuclei to look insight hyperon-nucleon interactions in the neutron rich medium

  11. Exchangers of inorganic ions in the administration of radioactive wastes; Intercambiadores de iones inorganicos en la gestion de desechos radioactivos

    Energy Technology Data Exchange (ETDEWEB)

    Badillo A, V. E.; Lopez R, C., E-mail: veronica.badillo@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-11-15

    The prediction of the radionuclide migration in geologic mean requires of a quantitative knowledge of the physiochemical phenomenon of retention in the surface of mineral phases. With this purpose, is necessary the study of the radionuclides retention in solids named model solids are the oxides and phosphates of polyvalent cations. This work presents experimental evidence of the convenience of using two exchangers of inorganic ions, alumina and apatite, in the administration of radioactive wastes due to its selectivity for the main products of divalent fission, Pd and Sr with regard to the anion species represented by Tc. The retention of Sr(III), Pd(II) and Tc(-I) in hydroxyapatite and alumina, in NaCl O.02 M in function of the ph is studied. The likeness of retention of the solids for the fission products is expressed in terms of the distribution coefficient kD which is obtained using the homologous radionuclides {sup 109}Pd and {sup 87m}Sr as well as the {sup 99m}Tc. The retention of Pd was of 100% and the Tc near to 0%. (Author)

  12. Advanced target concepts for production of radioactive ions and neutrino beams

    CERN Document Server

    Ravn, H L

    2003-01-01

    The 1-20 MW of proton beam power which modern accelerator technology put at our disposal for production of intense secondary beams presents a major technically challenge to the production targets. A conceptual design is presented for a high-power pion production target and collection system, which was originally suggested to be used as the source for the proposed CERN muon-neutrino factory. It will be shown that the major parts of this target could also serve as an efficient spallation neutron source for production of 6He and fission products in the two-step converter-target concept. The heart of the system consists of a free surface Mercury jet with a high axial velocity, which allows the heat to be carried away efficiently from the production region. For the neutrino factory the secondary pions are collected and injected into the pion decay-channel by means of a magnetic horn. For the radioactive ion-beam facility the Hg-jet is surrounded by the high-temperature ISOL production-target. The suggested mechani...

  13. High Power Molten Targets for Radioactive Ion Beam Production: from Particle Physics to Medical Applications

    CERN Document Server

    De Melo Mendonca, T M

    2014-01-01

    Megawatt-class molten targets, combining high material densities and good heat transfer properties are being considered for neutron spallation sources, neutrino physics facilities and radioactive ion beam production. For this last category of facilities, in order to cope with the limitation of long diffusion times affecting the extraction of short-lived isotopes, a lead-bismuth eutectic (LBE) target loop equipped with a diffusion chamber has been proposed and tested offline during the EURISOL design study. To validate the concept, a molten LBE loop is now in the design phase and will be prototyped and tested on-line at CERN-ISOLDE. This concept was further extended to an alternative route to produce 1013 18Ne/s for the Beta Beams, where a molten salt loop would be irradiated with 7 mA, 160 MeV proton beam. Some elements of the concept have been tested by using a molten fluoride salt static unit at CERNISOLDE. The investigation of the release and production of neon isotopes allowed the measurement of the diffu...

  14. Determination of the isomeric fraction in a postaccelerated radioactive ion beam using the coupled decay-chain equations

    CERN Document Server

    Ekstrom, A; Dijulio, D D; Cederkall, J; Van de Walle, J

    2010-01-01

    A method based on the coupled decay-chain equations for extracting the isotopic and the isomeric composition of a postaccelerated radioactive ion beam is presented and demonstrated on a data set from a Coulomb excitation experiment. This is the first attempt of analyzing the content of a postaccelerated radioactive ion beam using this technique. The beam composition is required for an absolute normalization of the measurement. The strength of the method, as compared to present online-based methods, lies in the determination of the isomeric fraction of a partially isomeric beam using all data accumulated during the experiment. We discuss the limitations and sensitivity of the method with respect to the gamma-ray detection efficiency and the accumulated flux. (C) 2010 Elsevier B.V. All rights reserved.

  15. Collinear laser spectroscopy on radioactive praseodymium ions and cadmium ions; Kollineare Laserspektroskopie an radioaktiven Praseodymionen und Cadmiumatomen

    Energy Technology Data Exchange (ETDEWEB)

    Froemmgen, Nadja

    2013-11-21

    Collinear laser spectroscopy is a tool for the model independent determination of spins, charge radii and electromagnetic moments of nuclei in ground and long-lived isomeric states. In the context of this thesis a new offline ion source for high evaporating temperatures and an ion beam analysis system were implemented at the TRIGA-LASER Experiment at the Institute for Nuclear Chemistry at the University of Mainz. The main part of the thesis deals with the determination of the properties of radioactive praseodymium and cadmium isotopes by collinear laser spectroscopy at ISOLDE/CERN. The necessary test measurements for the spectroscopy of praseodymium ions have been conducted with the aforementioned offline ion source at the TRIGA-LASER experiment. The spectroscopy of the praseodymium ions was motivated by the observation of a modulation of the electron capture decay rates of hydrogen-like {sup 140}Pr{sup 58+}. The nuclear magnetic moment of the nucleus is, among others, required for the explanation of the so-called GSI Oscillations and has not been studied experimentally before. Additionally, the determined electron capture decay constant of hydrogen-like {sup 140}Pr{sup 58+} is lower than the one of helium-like {sup 140}Pr{sup 57+}. The explanation of this phenomenon requires a positive magnetic moment. During the experiment at the COLLAPS apparatus the magnetic moments of the neutron-deficient isotopes {sup 135}Pr, {sup 136}Pr and {sup 137}Pr could be determined for the first time. Unfortunately, due to a too low production yield the desired isotope {sup 140}Pr could not be studied.The systematic study of cadmium isotopes was motivated by nuclear physics in the tin region. With Z=48 two protons are missing for the shell closure and the isotopes extend from the magic neutron number N=50 to the magic neutron number N=82. The extracted nuclear properties allow tests of different nuclear models in this region. In this thesis the obtained results of the spectroscopy of

  16. Neutron-rich rare isotope production from projectile fission of heavy beams in the energy range of 20 MeV/nucleon

    CERN Document Server

    Vonta, N; Loveland, W D; Kwon, Y K; Tshoo, K; Jeong, S C; Veselsky, M; Bonasera, A; Botvina, A

    2016-01-01

    We investigate the possibilities of producing neutron-rich nuclides in projectile fission of heavy beams in the energy range of 20 MeV/nucleon expected from low-energy facilities. We report our efforts to theoretically describe the reaction mechanism of projectile fission following a multinucleon transfer collision at this energy range. Our calculations are mainly based on a two-step approach: the dynamical stage of the collision is described with either the phenomenological Deep-Inelastic Transfer model (DIT), or with the microscopic Constrained Molecular Dynamics model (CoMD). The deexcitation/fission of the hot heavy projectile fragments is performed with the Statistical Mul- tifragmentation Model (SMM). We compared our model calculations with our previous experimental projectile-fission data of 238U (20 MeV/nucleon)+208Pb and 197Au (20 MeV/nucleon)+197Au and found an overall reasonable agreement. Our study suggests that projectile fission following periph- eral heavy-ion collisions at this energy range of...

  17. Setting up the photoluminescence laboratory at ISOLDE & Perturbed Angular Correlation spectroscopy for BIO physics experiments using radioactive ions

    CERN Document Server

    Savva, Giannis

    2016-01-01

    The proposed project I was assigned was to set up the photoluminescence (PL) laboratory at ISOLDE, under the supervision of Karl Johnston. My first week at CERN coincided with the run of a BIO physics experiment using radioactive Hg(II) ions in which I also participated under the supervision of Stavroula Pallada. This gave me the opportunity to work in two projects during my stay at CERN and in the present report I describe briefly my contribution to them.

  18. Design of a two-ion-source (2-IS) beam transport line for the production of multi charged radioactive ion beams

    CERN Document Server

    Banerjee, V; Bandyopadhyay, A; Chattopadhyay, S; Polley, A; Nakagawa, T; Kamigaito, O; Goto, A; Yano, Y

    2000-01-01

    A 'two-ion-source' beam transport line between a surface ionization source and a 6.4 GHz on-line Electron Cyclotron Resonance Ion Source (ECRIS) for the production of multi-charged radioactive ions has been designed. The 1 sup + ions from the surface ionization source are decelerated and focused onto the ECRIS plasma so that they can be efficiently trapped there and further ionized to charge state q>1 sup +. A scheme for stepwise and gradual deceleration of the 1 sup + ion beam consisting of a multi-electrode decelerator and a tuning electrode placed before the ECRIS has been optimized. The beam dynamics calculations show that the 1 sup + beam decelerated to energies of 20-50 eV could be focused to a spot size smaller than the radial dimensions of the ECR plasma zone.

  19. Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams.

    Science.gov (United States)

    Manzolaro, M; Meneghetti, G; Andrighetto, A; Vivian, G

    2016-03-01

    The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The transfer line enables the unstable isotopes generated by the (238)U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

  20. Electrical-thermal-structural finite element simulation and experimental study of a plasma ion source for the production of radioactive ion beams

    Science.gov (United States)

    Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.

    2016-03-01

    The production target and the ion source constitute the core of the selective production of exotic species (SPES) facility. In this complex experimental apparatus for the production of radioactive ion beams, a 40 MeV, 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The transfer line enables the unstable isotopes generated by the 238U fissions in the target to reach the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work, the plasma ion source currently adopted for the SPES facility is analyzed in detail by means of electrical, thermal, and structural numerical models. Next, theoretical results are compared with the electric potential difference, temperature, and displacement measurements. Experimental tests with stable ion beams are also presented and discussed.

  1. Shell-model studies of the N=14 and 16 shell closures in neutron-rich nuclei

    Institute of Scientific and Technical Information of China (English)

    YUAN Cen-Xi; QI Chong; XU Fu-Rong

    2009-01-01

    Shell-model studies on the N = 14 and 16 shell closures in neutron-rich Be, C, O and Ne isotopes are presented. We calculate, with the WBT interaction, the excited states in these nuclei. The calculations agree with recent experiment data. Excited energies and B(E2) values are displayed to discuss the shell closures.Our results support the N = 16 shell closure in these isotopes, while indicating a disappearance of N = 14 shell closure in Be and C isotopes.

  2. Spectroscopy of neutron rich nuclei using cold neutron induced fission of actinide targets at the ILL: the EXILL campaign

    Directory of Open Access Journals (Sweden)

    de France G.

    2014-03-01

    Full Text Available A combination of germanium detectors has been installed at the PF1B neutron guide of the ILL to perform the prompt spectroscopy of neutron-rich nuclei produced in the neutron-capture induced-fission of 235U and 241Pu. In addition LaBr3 detectors from the FATIMA collaboration have been installed in complement with the EXOGAM clovers to measure lifetimes of low-lying excited states. The measured characteristics and online spectra indicate very good performances of the overall setup.

  3. New Levels in 118pd Observed in theβ Decay of Very Neutron-Rich 118Rh Isotope

    Institute of Scientific and Technical Information of China (English)

    WANG You-Bao; K. Per(a)j(a)rvi; S. Rinta-Antila; J. Szerypo; J. C. Wang; J. (A)yst(o); P. Dendooven; J. Huikari; A. Jokinen; V. S. Kolhinen; G. Lhersonneau; A. Nieminen; S. Nummela; H. Penttil(a)

    2006-01-01

    @@ We investigate theβ decay of very neutron-rich 118Rh isotope using on-line mass-separated sources which are produced by applying 25 Me V proton induced symmetric fission of natural uranium at the IGISOL facility. The β-γ and γ-γ coincidence spectroscopy is employed to establish the level scheme of daughter nucleus 118 pd. Five low-lying new levels are identified for the first time with tentative spin and parity assignments based on the even-mass Pd systematics.

  4. First one-line mass measurements at SHIPTRAP and mass determinations of neutron-rich Fr and Ra isotopes at ISOLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Rahaman, M.S.

    2005-02-16

    SHIPTRAP is an ion trap facility behind the velocity lter SHIP at GSI/Darmstadt. Its aim are precision studies of transuranium nuclides produced in a fusion reaction and separated by SHIP. The current set-up for high-precision mass measurements consists of three main functional parts: (i) a gas cell for stopping the energetic ions from SHIP, (ii) radiofrequency quadrupole structures to cool and to bunch the ions extracted from the gas cell, and (iii) a superconducting magnet with two cylindrical Penning traps at a eld strength of 7 T. In this work the Penning trap system has been installed and extensively characterized. The rst on-line mass measurements of short-lived nuclides were carried out and the masses of {sup 147}Er and {sup 148}Er could be experimentally determined for the rst time. Here a relative mass uncertainty of {delta}m/m of about 1 x 10{sup -6} was achieved. Furthermore the masses of heavy neutron-rich {sup 229-232}Ra and {sup 230}Fr isotopes have been determined with a relative mass uncertainty of about 1 x 10{sup -7} with the ISOLTRAP mass spectometer at ISOLDE/CERN. The isotope {sup 232}Ra is the heaviest unstable nuclide ever investigated with a Penning trap. Underlying nuclear structure effects of these nuclides far from {beta}-stability were studied by a comparison of the resulting two-neutron separation energies S{sub 2n} with those given by the theoretical Infinite Nuclear Mass model. (orig.)

  5. Development of materials for the removal of metal ions from radioactive and non-radioactive waste streams

    Science.gov (United States)

    Hasan, Md. Shameem

    Nuclear wastes that were generated during cold-war era from various nuclear weapon programs are presently stored in hundreds of tanks across the United States. The composition of these wastes is rather complex containing both radionuclides and heavy metals, such as 137Cs, 90Sr, Al, Pb, Cr, and Cd. In this study, chitosan based biosorbents were prepared to adsorb some of these metal ions. Chitosan is a partially acetylated glucosamine biopolymer encountered in the cell walls of fungi. In its natural form this material is soft and has a tendency to agglomerate or form gels. Various methods were used to modify chitosan to avoid these problems. Chitosan is generally available commercially in the form of flakes. For use in an adsorption system, chitosan was made in the form of beads to reduce the pressure drop in an adsorption column. In this research, spherical beads were prepared by mixing chitosan with perlite and then by dropwise addition of the slurry mixture into a NaOH precipitation bath. Beads were characterized using Fourier Transform InfraRed Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy dispersive spectroscopy (EDS), Tunneling Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Thermogravimetric Analysis (TGA). The SEM, EDS, and TEM data indicated that the beads were porous in nature. The TGA data showed that bead contained about 32% chitosan. The surface area, pore volume, and porosity of the beads were determined from the BET surface area that was measured using N2 as adsorbate at 77K. Adsorption and desorption of Cr(VI), Cr(III), Cd(II), U(VI), Cu(II), from aqueous solutions of these metal ions were studied to evaluate the adsorption capacities of the beads for these metals ions. Equilibrium adsorption data of these metals on the beads were found to correlate well with the Langmuir isotherm equation. Chitosan coated perlite beads had negligible adsorption capacity for Sr(II) and Cs(I). It was found that Fullers earth

  6. Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams.

    Science.gov (United States)

    Manzolaro, M; Meneghetti, G; Andrighetto, A; Vivian, G; D'Agostini, F

    2016-02-01

    In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10(13) fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

  7. 用于产生放射性离子束ECR离子源%ECR Ion Sources for Radioactive Ion Beam Production

    Institute of Scientific and Technical Information of China (English)

    P.Jardin; F.Lemagnen; R.Leroy; J.Y.Pacquet; M.G.Saint Laurent; A.C.C.Villari; C.Canet; J.C.Cornell; M.Dupuis; C.Eleon; J.L.Flambard; G.Gaubert; N.Lecesne; P.Leherissier

    2007-01-01

    ECRIS's dedicated to radioactive ion production must be as efficient as those used for production of stable elements,but in addition they are subject to more specific constraints such as radiation hardness,short atom-to-ion transformation time,beam purity and low cost.Up to now,different target/ion-source systems(TISSs)have been designed,using singly-charged ECRISs,multi.charged ion sources or an association of singly-to-multi-charged ECRISs.The main goals,constraints and advantages of different existing ECR setups will be compared before a more detailed description is given of the one designed for the SPIRAL Ⅱ project and its future improvements.

  8. Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Manzolaro, M., E-mail: mattia.manzolaro@lnl.infn.it; Andrighetto, A. [INFN, Laboratori Nazionali di Legnaro, Viale dell’Universita’ 2, Legnaro, 35020 Padova (Italy); Meneghetti, G. [Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padova (Italy); Vivian, G.; D’Agostini, F. [INFN, Laboratori Nazionali di Legnaro, Viale dell’Universita’ 2, Legnaro, 35020 Padova (Italy); Department of Industrial Engineering, University of Padova, Via Venezia 1, 35131 Padova (Italy)

    2016-02-15

    In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 10{sup 13} fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

  9. Thermal-electric coupled-field finite element modeling and experimental testing of high-temperature ion sources for the production of radioactive ion beams

    Science.gov (United States)

    Manzolaro, M.; Meneghetti, G.; Andrighetto, A.; Vivian, G.; D'Agostini, F.

    2016-02-01

    In isotope separation on line facilities the target system and the related ion source are two of the most critical components. In the context of the selective production of exotic species (SPES) project, a 40 MeV 200 μA proton beam directly impinges a uranium carbide target, generating approximately 1013 fissions per second. The radioactive isotopes produced in this way are then directed to the ion source, where they can be ionized and finally accelerated to the subsequent areas of the facility. In this work both the surface ion source and the plasma ion source adopted for the SPES facility are presented and studied by means of numerical thermal-electric models. Then, numerical results are compared with temperature and electric potential difference measurements, and finally the main advantages of the proposed simulation approach are discussed.

  10. Submicro and Nano Structured Porous Materials for the Production of High-Intensity Exotic Radioactive Ion Beams

    CERN Document Server

    Fernandes, Sandrina; Stora, Thierry

    2010-01-01

    ISOLDE, the CERN Isotope Separator On-line DEvice is a unique source of low energy beams of radioactive isotopes - atomic nuclei that have too many or too few neutrons to be stable. The facility is like a small ‘chemical factory’, giving the possibility of changing one element to another, by selecting the atomic mass of the required isotope beam in the mass separator, rather as the ‘alchemists’ once imagined. It produces a total of more than 1000 different isotopes from helium to radium, with half-lives down to milliseconds, by impinging a 1.4 GeV proton beam from the Proton Synchrotron Booster (PSB) onto special targets, yielding a wide variety of atomic fragments. Different components then extract the nuclei and separate them according to mass. The post-accelerator REX (Radioactive beam EXperiment) at ISOLDE accelerates the radioactive beams up to 3 MeV/u for many experiments. A wide international user radioactive ion beam (RIB) community investigates fundamental aspects of nuclear physics, particle...

  11. Impact of new data for neutron-rich heavy nuclei on theoretical models for r-process nucleosynthesis

    Science.gov (United States)

    Kajino, Toshitaka; Mathews, Grant J.

    2017-08-01

    Current models for the r process are summarized with an emphasis on the key constraints from both nuclear physics measurements and astronomical observations. In particular, we analyze the importance of nuclear physics input such as beta-decay rates; nuclear masses; neutron-capture cross sections; beta-delayed neutron emission; probability of spontaneous fission, beta- and neutron-induced fission, fission fragment mass distributions; neutrino-induced reaction cross sections, etc. We highlight the effects on models for r-process nucleosynthesis of newly measured β-decay half-lives, masses, and spectroscopy of neutron-rich nuclei near the r-process path. We overview r-process nucleosynthesis in the neutrino driven wind above the proto-neutron star in core collapse supernovae along with the possibility of magneto-hydrodynamic jets from rotating supernova explosion models. We also consider the possibility of neutron star mergers as an r-process environment. A key outcome of newly measured nuclear properties far from stability is the degree of shell quenching for neutron rich isotopes near the closed neutron shells. This leads to important constraints on the sites for r-process nucleosynthesis in which freezeout occurs on a rapid timescale.

  12. Mass measurements of neutron rich isotopes in the Fe region and electron capture processes in neutron star crusts

    Energy Technology Data Exchange (ETDEWEB)

    Estrade, Alfredo [National Superconducting Cyclotron Laboratory (NSCL); Matos, M. [Louisiana State University; Schatz, Hendrik [Michigan State University, East Lansing; Amthor, A. M. [National Superconducting Cyclotron Laboratory (NSCL); Beard, Mary [University of Notre Dame, IN; Brown, Edward [Michigan State University, East Lansing; Bazin, D. [National Superconducting Cyclotron Laboratory (NSCL); Becerril, A. [National Superconducting Cyclotron Laboratory (NSCL); Elliot, T [National Superconducting Cyclotron Laboratory (NSCL); Gade, A. [National Superconducting Cyclotron Laboratory (NSCL); Galaviz, D. [National Superconducting Cyclotron Laboratory (NSCL); Gupta, Sanjib [Indian Institute of Technology, Kanpur; Hix, William Raphael [ORNL; Lau, Rita [National Superconducting Cyclotron Laboratory (NSCL); Moeller, Peter [Los Alamos National Laboratory (LANL); Pereira, J. [National Superconducting Cyclotron Laboratory (NSCL); Portillo, M. [National Superconducting Cyclotron Laboratory (NSCL); Rogers, A. M. [National Superconducting Cyclotron Laboratory (NSCL); Shapira, Dan [ORNL; Smith, E. [Ohio State University; Stolz, A. [Michigan State University, East Lansing; Wallace, M. [Los Alamos National Laboratory (LANL); Wiescher, Michael [University of Notre Dame, IN

    2010-01-01

    Experimental knowledge of nuclear masses of exotic nuclei is important for understanding nu- clear structure far from the valley of -stability, and as a direct input into astrophysical models. Electron capture processes in the crust of accreting neutron stars have been proposed as a heat source that can affect the thermal structure of the star. Nuclear masses of very neutron-rich nu- clides are necessary inputs to model the electron capture process. The time-of-flight (TOF) mass measurement technique allows measurements on very short-lived nuclei. It has been effectively applied using the fast fragment beams produced at the National Superconducting Cyclotron Lab (NSCL) to reach masses very far from stability. Measurements were performed for neutron-rich isotopes in the region of the N=32 and N=40 subshells, which coincides with the mass range of carbon superburst ashes. We discuss reaction network calculations performed to investigate the impact of our new measurements and to compare the effect of using different global mass models in the calculations. It is observed that the process is sensitive to the differences in the odd-even mass staggering predicted by the mass models, and our new result for 66Mn has a significant impact on the distribution of heat sources in the crust.

  13. Identification of new neutron-rich rare-earth nuclei produced in /sup 252/Cf spontaneous fission

    CERN Document Server

    Greenwood, R C; Gehrke, R J; Meikrantz, D H

    1981-01-01

    A program of systematic study of the decay properties of neutron-rich rare-earth nuclei with 30 sneutron-rich rare-earth isotopes including /sup 155/Pm (t/sub 1/2/=48+or-4 s) and /sup 163/Gd (t/sub 1 /2/=68+or-3 s), in addition to 5.51 min /sup 158/Sm which was identified in an earlier series of experiments. (11 refs).

  14. Ground-state properties and symmetry energy of neutron-rich and neutron-deficient Mg isotopes

    CERN Document Server

    Gaidarov, M K; Antonov, A N; de Guerra, E Moya

    2015-01-01

    A comprehensive study of various ground-state properties of neutron-rich and neutron-deficient Mg isotopes with $A$=20-36 is performed in the framework of the self-consistent deformed Skyrme-Hartree-Fock plus BCS method. The correlation between the skin thickness and the characteristics related with the density dependence of the nuclear symmetry energy is investigated for this isotopic chain following the theoretical approach based on the coherent density fluctuation model and using the Brueckner energy-density functional. The results of the calculations show that the behavior of the nuclear charge radii and the nuclear symmetry energy in the Mg isotopic chain is closely related to the nuclear deformation. We also study, within our theoretical scheme, the emergence of an "island of inversion" at neutron-rich $^{32}$Mg nucleus, that was recently proposed from the analyses of spectroscopic measurements of $^{32}$Mg low-lying energy spectrum and the charge rms radii of all magnesium isotopes in the $sd$ shell.

  15. The identification of autoionizing states of atomic chromium for the resonance ionization laser ion source of the ISOLDE radioactive ion beam facility

    Science.gov (United States)

    Day Goodacre, T.; Chrysalidis, K.; Fedorov, D. V.; Fedosseev, V. N.; Marsh, B. A.; Molkanov, P. L.; Rossel, R. E.; Rothe, S.; Seiffert, C.

    2017-03-01

    This paper presents the results of an investigation into autoionizing states of atomic chromium, in the service of the resonance ionization laser ion source (RILIS): the principal ion source of the ISOLDE radioactive ion beam facility based at CERN. The multi-step resonance photo-ionization process enables element selective ionization which, in combination with mass separation, allows isotope specific selectivity in the production of radioactive ion beams at ISOLDE. The element selective nature of the process requires a multi-step "ionization scheme" to be developed for each element. Using the method of in-source resonance ionization spectroscopy, an optimal three-step, three-resonance photo-ionization scheme originating from the 3d5(6S)4s a7S3 atomic ground state has been developed for chromium. The scheme uses an ionizing transition to one of the 15 newly observed autoionizing states reported here. Details of the spectroscopic studies are described and the new ionization scheme is summarized.

  16. Titanium carbide-carbon porous nanocomposite materials for radioactive ion beam production: processing, sintering and isotope release properties

    CERN Document Server

    AUTHOR|(CDS)2081922; Stora, Thierry

    2017-01-26

    The Isotope Separator OnLine (ISOL) technique is used at the ISOLDE - Isotope Separator OnLine DEvice facility at CERN, to produce radioactive ion beams for physics research. At CERN protons are accelerated to 1.4 GeV and made to collide with one of two targets located at ISOLDE facility. When the protons collide with the target material, nuclear reactions produce isotopes which are thermalized in the bulk of the target material grains. During irradiation the target is kept at high temperatures (up to 2300 °C) to promote diffusion and effusion of the produced isotopes into an ion source, to produce a radioactive ion beam. Ti-foils targets are currently used at ISOLDE to deliver beams of K, Ca and Sc, however they are operated at temperatures close to their melting point which brings target degradation, through sintering and/or melting which reduces the beam intensities over time. For the past 10 years, nanostructured target materials have been developed and have shown improved release rates of the produced i...

  17. Production of neutron-rich isotopes by cold fragmentation in the reaction {sup 197}Au + Be at 950 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Benlliure, J.; Pereira, J. [Universidad de Santiago de Compostela (Spain)]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Schmidt, K.H.; Cortina-Gil, D.; Enqvist, T.; Heinz, A.; Junghans, A.R. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Farget, F. [Institut de Physique Nucleaire, 91 - Orsay (France); Taieb, J. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)]|[Institut de Physique Nucleaire, 91 - Orsay (France)

    1999-09-01

    The production cross sections and longitudinal-momentum distributions of very neutron-rich isotopes have been investigated in the fragmentation of a 950 A MeV {sup 179}Au beam in a beryllium target. Seven new isotopes ({sup 193}Re, {sup 194}Re, {sup 191}W, {sup 192}W, {sup 189}Ta, {sup 187}Hf and {sup 188}Hf) and the five-proton-removal channel were observed for the first time. The reaction mechanism leading to the formation of these very neutron-rich isotopes is explained in terms of the cold-fragmentation process. An analytical model describing this reaction mechanism is presented. (orig.)

  18. $\\beta$-decay study of neutron-rich Tl, Pb, and Bi by means of the pulsed-release technique and resonant laser ionisation

    CERN Multimedia

    Lettry, J

    2002-01-01

    It is proposed to study new neutron-rich nuclei around the Z = 82 magic shell closure, with major relevance for understanding the evolution of nuclear structure at extreme isospin values. Following the IS354 experiment, $\\beta$-decay studies of neutron-rich thallium, lead and bismuth isotopes will be performed for 215 $\\leqslant$ A $\\leqslant$ 219. To this purpose the pulsed-release technique, which was pioneered at ISOLDE, will be optimised. It will be complemented with the higher element selectivity that can be obtained by the unique features of resonant laser ionisation, available at ISOLDE from the RILIS source.

  19. Trojan Horse method and radioactive ion beams: study of $^{18}$F(p,$\\alpha$)$^{15}$O reaction at astrophysical energies

    CERN Document Server

    Gulino, M; Rapisarda, G G; Kubono, S; Lamia, L; La Cognata, M; Yamaguchi, H; Hayakawa, S; Wakabayashi, Y; Iwasa, N; Kato, S; Komatsubara, H; Teranishi, T; Coc, A; De Séréville, N; Hammache, F; Spitaleri, C

    2012-01-01

    The Trojan Horse Method was applied for the first time to a Radioactive Ion Beam induced reaction to study the reaction $^{18}$F(p,$\\alpha$)$^{15}$O via the three body reaction $^{18}$F(d,$\\alpha$ $^{15}$O)n at the low energies relevant for astrophysics. The abundance of $^{18}$F in Nova explosions is an important issue for the understanding of this astrophysical phenomenon. For this reason it is necessary to study the nuclear reactions that produce or destroy $^{18}$F in Novae. $^{18}$F(p,$\\alpha$)$^{15}$O is one of the main $^{18}$F destruction channels. Preliminary results are presented in this paper.

  20. Reaction dynamics induced by the radioactive ion beam 7Be on medium-mass and heavy targets

    Science.gov (United States)

    Mazzocco, M.; Boiano, A.; Boiano, C.; La Commara, M.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Stefanini, C.; Strano, E.; Torresi, D.; Acosta, L.; Di Meo, P.; Fernandez-Garcia, J. P.; Glodariu, T.; Grebosz, J.; Guglielmetti, A.; Keeley, N.; Lay, J. A.; Marquinez-Duran, G.; Martel, I.; Mazzocchi, C.; Molini, P.; Nicoletto, M.; Pakou, A.; Parkar, V. V.; Rusek, K.; Sánchez-Benítez, A. M.; Sandoli, M.; Sava, T.; Sgouros, O.; Signorini, C.; Silvestri, R.; Soramel, F.; Soukeras, V.; Stiliaris, E.; Stroe, L.; Toniolo, N.; Zerva, K.

    2015-10-01

    We studied the reaction dynamics induced at Coulomb barrier energies by the weakly-bound Radioactive Ion Beam 7Be (Sα = 1.586 MeV) on medium-mass (58Ni) and heavy (208Pb) targets. The experiments were performed at INFN-LNL (Italy), where a 2-3×105 pps 7Be secondary beam was produced with the RIB in-flight facility EXOTIC. Charged reaction products were detected by means of high-granularity silicon detectors in rather wide angular ranges. The contribution presents an up-to-date status of the data analysis and theoretical interpretation for both systems.

  1. First results of Trojan horse method using radioactive ion beams: {sup 18}F(p,α) at astrophysical energies

    Energy Technology Data Exchange (ETDEWEB)

    Cherubini, S.; Spitaleri, C.; Puglia, S.; Rapisarda, G.; Romano, S. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy); Gulino, M. [Università KORE, Enna, Italy and INFN - Laboratori Nazionali del Sud, Catania (Italy); La Cognata, M. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Lamia, L. [Dipartimento di Fisica e Astronomia, Università di Catania, Catania (Italy); Kubono, S.; Wakabayashi, Y. [Center for Nuclear Study, University of Tokyo, Tokyo, Japan and present address RIKEN Nishina Center, Wako, Saitama (Japan); Yamaguchi, H.; Hayakawa, S.; Kurihara, Y. [Center for Nuclear Study, University of Tokyo, Tokyo (Japan); Binh, D. [Center for Nuclear Study, University of Tokyo, Tokyo, Japan and present address Institute of Physics and Electronics, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Bishop, S. [RIKEN Nishina Center, Wako, Saitama, Japan and present address Physik Department E12, Technische Universität München, Garching (Germany); Coc, A. [Centre de Spectrométrie Nucléaire et de Spectrométrie de masse, IN2P3, Orsay (France); De Séréville, N.; Hammache, F. [Institut de Physique Nucléaire, IN2P3, Orsay (France)

    2014-05-02

    The abundance of {sup 18}F in Nova explosions is considered to be an important piece of information for the understanding of this astrophysical phenomenon. It is then necessary to study the nuclear processess that both produce and destroy this isotope in Novae. Among these latter reactions, the {sup 18}F(p,α){sup 15}O is one of the most important {sup 18}F destruction channels. Here we report on an experiment performed using the CRIB apparatus of the Center for Nuclear Study of the University of Tokyo. This was the first experiment that used the Trojan Horse method applied to a Radioactive Ion Beam induced reaction.

  2. One- and two neutron decay of light neutron-rich nuclei

    Science.gov (United States)

    Thoennessen, Michael

    2014-09-01

    Direct reactions with radioactive beams have been used very successfully to populate and measure nuclei beyond the neutron dripline and neutron unbound excited states of nuclei close to the neutron dripline. The use of different reactions (for example neutron removal and proton removal) to populate the same final nucleus can be used to selectively populate different states. Recent results from the MoNA-LISA setup at the NSCL, including 10He, 10,11Li, and 12,13Be will be presented. Direct reactions with radioactive beams have been used very successfully to populate and measure nuclei beyond the neutron dripline and neutron unbound excited states of nuclei close to the neutron dripline. The use of different reactions (for example neutron removal and proton removal) to populate the same final nucleus can be used to selectively populate different states. Recent results from the MoNA-LISA setup at the NSCL, including 10He, 10,11Li, and 12,13Be will be presented. This work was supported in part by the NSF, Grant PHY-11-02511.

  3. Beta-Decay Half-Lives and Neutron-Emission Probabilities of Very Neutron-Rich Y to Tc Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Mehren, T.; Pfeiffer, B.; Schoedder, S.; Kratz, K. [Institut fuer Kernchemie, Universitaet Mainz, D-55099 Mainz (Germany); Huhta, M.; Dendooven, P.; Honkanen, A.; Lhersonneau, G.; Oinonen, M.; Parmonen, J.; Penttilae, H.; Popov, A.; Rubchenya, V.; Aeystoe, J. [Department of Physics, Accelerator Laboratory, University of Jyvaeskylae, FIN-40351 Jyvaeskylae (Finland)

    1996-07-01

    Neutron-rich {sub 39}Y to {sub 43}Tc isotopes have been produced by fission of uranium with a 50MeV H{sub 2}{sup +} beam. Beta-decay half-lives, delayed neutron-emission probabilities, and production yields have been measured and compared with theory. Beta decay of 4 new isotopes is reported, and the {beta}-delayed neutron-emission mode has been discovered for 12 isotopes of the elements niobium and technetium. The results compared to quasiparticle random phase approximation predictions indicate the increasing importance of fast {beta} transitions to high-lying states of nuclei with large neutron excess. {copyright} {ital 1996 The American Physical Society.}

  4. Competing γ-rigid and γ-stable vibrations in neutron-rich Gd and Dy isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Budaca, R.; Budaca, A.I. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

    2015-10-15

    An exactly separable version of the Bohr Hamiltonian which combines the γ-stable and γ-rigid axial vibration-rotation is used to describe the collective properties of few neutron-rich transitional nuclei. The coupling between the two types of collective motion is managed through a rigidity parameter which also influences the geometry of the shape phase space. While the γ-angular part of the problem associated to axially symmetric shapes is treated within the small angles approximation and the stiff γ oscillation hypothesis, the β vibration is described by means of a Davidson potential. The resulting model have three free parameters not counting the scale and was successfully applied for the description of the collective spectra for few heavier isotopes of Gd and Dy. In both cases a critical nucleus was identified through a discontinuous behavior in respect to the rigidity parameter and relevant experimental observables. (orig.)

  5. Low-lying level structure of the neutron-rich nucleus {sup 109}Nb: A possible oblate-shape isomer

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H., E-mail: hiroshi@ribf.riken.j [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Sumikama, T. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Li, Z. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Miyashita, Y. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Yamaguchi, K. [Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka 560-0043 Toyonaka (Japan); Baba, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Berryman, J.S. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Blasi, N. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Bracco, A.; Camera, F. [INFN, Sezione di Milano, via Celoria 16, I-20133 Milano (Italy); Dipartimento di Fisica, Universita di Milano, via Celoria 16, I-20133 Milano (Italy); Chiba, J. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba (Japan); Doornenbal, P. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Go, S.; Hashimoto, T.; Hayakawa, S. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Hinke, C. [Physik Department, Technische Universitaet Muenchen, D-85748 Garching (Germany); Ideguchi, E. [Center for Nuclear Study, University of Tokyo, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Isobe, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2011-01-31

    The neutron-rich nuclei {sup 109}Nb and {sup 109}Zr have been populated using in-flight fission of a {sup 238}U beam at 345 MeV/nucleon at the RIBF facility. A T{sub 1/2}=150(30) ns isomer at 313 keV has been identified in {sup 109}Nb for the first time. The low-lying levels in {sup 109}Nb have been also populated following the {beta}-decay of {sup 109}Zr. Based on the difference in feeding pattern between the isomeric and {beta} decays, the decay scheme from the isomeric state in {sup 109}Nb was established. The observed hindrances of the electromagnetic transitions deexciting the isomeric state are discussed in terms of possible shape coexistence. Potential energy surface calculations for single-proton configurations predict the presence of low-lying oblate-deformed states in {sup 109}Nb.

  6. Study of Ground State Wave-function of the Neutron-rich 29,30Na Isotopes through Coulomb Breakup

    Directory of Open Access Journals (Sweden)

    Rahaman A.

    2014-03-01

    Full Text Available Coulomb breakup of unstable neutron rich nuclei 29,30Na around the ‘island of inversion’ has been studied at energy around 434 MeV/nucleon and 409 MeV/nucleon respectively. Four momentum vectors of fragments, decay neutron from excited projectile and γ-rays emitted from excited fragments after Coulomb breakup are measured in coincidence. For these nuclei, the low-lying dipole strength above one neutron threshold can be explained by direct breakup model. The analysis for Coulomb breakup of 29,30Na shows that large amount of the cross section yields the 28Na, 29Na core in ground state. The predominant ground-state configuration of 29,30Na is found to be 28Na(g.s⊗νs1/2 and 29Na(g.s⊗νs1/2,respectively.

  7. Yrast structure of the neutron-rich N=31 isotones {sup 51}Ca and {sup 52}Sc.

    Energy Technology Data Exchange (ETDEWEB)

    Fornal, B.; Janssens, R. V. F.; Broda, R.; Marginean, N.; Beghini, S.; Carpenter, M. P.; Lauritsen, T.; Seweryniak, D.; Zhu, S.; Physics; Polish Academy of Sciences; INFN, Legnaro; Horia Hulubei; dell' Univ. di Padova; INFN; Univ. of Aizu; Joint Inst. for Heavy Ion Res.; Michigan State Univ.; Univ. of Tokyo; RIKEN; Univ. di Torino; Ruder Boskovic Inst.; INFN, Napoli

    2008-01-01

    The low-lying yrast states in the {sup 51}Ca and {sup 52}Sc nuclei were investigated to obtain information on the evolution of the p1/2 and f5/2 neutron single-particle orbitals in neutron-rich nuclei near proton number Z=20. Level structures associated with neutron excitations into these two orbitals and with proton excitations across the Z=20 shell gap were identified. Shell-model calculations with the recently proposed GXPF1A interaction account reasonably well for the fp-shell states. The energy separation between the {nu}p1/2 and {nu}f5/2 orbitals in the Ca isotopes appears to be overestimated by the GXPF1A Hamiltonian.

  8. Direct Mass Measurements in the Light Neutron-Rich Region Using a Combined Energy and Time-of-Flight Technique

    Science.gov (United States)

    Pillai, C.; Swenson, L. W.; Vieira, D. J.; Butler, G. W.; Wouters, J. M.; Rokni, S. H.; Vaziri, K.; Remsberg, L. P.

    This experiment has demonstrated that direct mass measurements can be performed (albeit of low precision in this first attempt) using the M proportional to ET(2) method. This technique has the advantage that many particle-bound nuclei, produced in fragmentation reactions can be measured simultaneously, independent of their N or Z. The main disadvantage of this approach is that both energy and time-of-flight must be measured precisely on an absolute scale. Although some mass walk with N and Z was observed in this experiment, these uncertainties were largely removed by extrapolating the smooth dependence observed for known nuclei which lie closer to the valley of (BETA)-stability. Mass measurements for several neutron-rich light nuclei ranging from C-17 to NE-26 have been performed. In all cases these measurements agree with the latest mass compilation of Wapstra and Audi. The masses of N-20 N and F-24 have been determined for the first time.

  9. Microscopic study of low-lying yrast spectra and deformation systematics in neutron-rich 98−106Sr isotopes

    Indian Academy of Sciences (India)

    Anil Chandan; Suram Singh; Arun Bharti; S K Khosa

    2009-10-01

    Variation-after-projection (VAP) calculations in conjunction with Hartree–Bogoliubov (HB) ansatz have been carried out for = 98–106 strontium isotopes. In this framework, the yrast spectra with ≥ 10+, (2) transition probabilities, quadrupole deformation parameter and occupation numbers for various shell model orbits have been obtained. The results of the calculation for yrast spectra give an indication that it is important to include the hexadecapole–hexadecapole component of the two-body interaction for obtaining various nuclear structure quantities in Sr isotopes. Besides this, it is also found that the simultaneous polarization of 3/2 and 5/2 proton subshells is a significant factor in making a sizeable contribution to the deformation in neutron-rich Sr isotopes.

  10. Future Perspectives in Nuclear Structure: From high intensity stable to radioactive nuclear beams

    Science.gov (United States)

    de Angelis, Giacomo

    2005-04-01

    Future perspectives in nuclear structure rely on radioactive nuclear beams as well as on high intensity beams of stable ions. Especially for neutron rich nuclei, deep-inelastic and multi-nucleon transfer reactions can be used to populate yrast and non yrast states. Particularly powerful is here the combination of large acceptance spectrometers with highly segmented γ-detector arrays. Such devices, eventually complemented by large cov- erage particle detectors, can provide the necessary channel selectivity to identify very rare signals. An example is the CLARA γ-ray detector array coupled with the PRISMA spectrometer at the Legnaro National Laboratories (LNL). The physics aims achievable with this setup will complement studies performed with current radioactive beam (RIB) facilities. With such set-up we have recently investigated the stability of the N=50 shell closure when moving towards more exotic systems. Here the comparison of the experi- mental data with shell model calculations seems to indicate a persistence of the N=50 shell gap down to Z=32. Future perspectives at LNL are based on an increase in in- tensity as well as on the availability of heavy ion species. Beams like 136Xe or 208Pb, which will be provided by the new PIAVE injector, can be used to drive the multinucleon flux toward the more exotic regions. Moreover a new ISOL facility (SPES) dedicated to the production and acceleration of radioactive neutron rich species is now under develop- ment at LNL. It will be based on an high intensity proton and deuteron LINAC. Induced fission fragments will be ionized and then accelerated using the presently existing super- conductive LINAC (ALPI). Among the new instrumentation the concept of γ-ray tracking has been recently introduced in nuclear spectroscopy. Detectors based on γ-ray tracking have position resolution capabilities with excellent performances both in efficiency and in achievable Doppler correction. A new γ-ray detector array (AGATA) based on

  11. Recent direct reaction experimental studies with radioactive tin beams

    CERN Document Server

    Jones, K L; Allmond, J M; Ayres, A; Bardayan, D W; Baugher, T; Bazin, D; Berryman, J S; Bey, A; Bingham, C; Cartegni, L; Cerizza, G; Chae, K Y; Cizewski, J A; Gade, A; Galindo-Uribarri, A; Garcia-Ruiz, R F; Grzywacz, R; Howard, M E; Kozub, R L; Liang, J F; Manning, B; Matos, M; McDaniel, S; Miller, D; Nesaraja, C D; O'Malley, P D; Padgett, S; Padilla-Rodal, E; Pain, S D; Pittman, S T; Radford, D C; Ratkiewicz, A; Schmitt, K T; Shore, A; Smith, M S; Stracener, D W; Stroberg, S R; Tostevin, J; Varner, R L; Weisshaar, D; Wimmer, K; Winkler, R

    2015-01-01

    Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine (ISOL) method. Some of the most interesting regions to study with direct reactions are close to the magic numbers where changes in shell structure can be tracked. These changes can impact the final abundances of explosive nucleosynthesis. The structure of the chain of tin isotopes is strongly influenced by the Z=50 proton shell closure, as well as the neutron shell closures lying in the neutron-rich, N=82, and neutron-deficient, N=50, regions. Here we present two examples of direct reactions on exotic tin isotopes. The first uses a one-neutron transfer reaction and a low-energy reaccelerated ISOL beam to study states in 131Sn from across the N=82 shell closure. The second example utilizes a one-neutron knockout reaction on fragmentation beams of neutron-deficient 106,108Sn...

  12. ZIRCONIUM—HAFNIUM ISOTOPE EVIDENCE FROM METEORITES FOR THE DECOUPLED SYNTHESIS OF LIGHT AND HEAVY NEUTRON-RICH NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Akram, W.; Schönbächler, M. [School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Sprung, P. [Institut für Planetologie, Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Vogel, N. [Institute for Geochemistry and Petrology, ETH, Clausiusstrasse 25, 8092 Zürich (Switzerland)

    2013-11-10

    Recent work based on analyses of meteorite and terrestrial whole-rock samples showed that the r- and s- process isotopes of Hf were homogeneously distributed throughout the inner solar system. We report new Hf isotope data for Calcium-Aluminum-rich inclusions (CAIs) of the CV3 carbonaceous chondrite Allende, and novel high-precision Zr isotope data for these CAIs and three carbonaceous chondrites (CM, CO, CK). Our Zr data reveal enrichments in the neutron-rich isotope {sup 96}Zr (≤1ε in {sup 96}Zr/{sup 90}Zr) for bulk chondrites and CAIs (∼2ε). Potential isotope effects due to incomplete sample dissolution, galactic and cosmic ray spallation, and the nuclear field shift are assessed and excluded, leading to the conclusion that the {sup 96}Zr isotope variations are of nucleosynthetic origin. The {sup 96}Zr enrichments are coupled with {sup 50}Ti excesses suggesting that both nuclides were produced in the same astrophysical environment. The same CAIs also exhibit deficits in r-process Hf isotopes, which provides strong evidence for a decoupling between the nucleosynthetic processes that produce the light (A ≤ 130) and heavy (A > 130) neutron-rich isotopes. We propose that the light neutron-capture isotopes largely formed in Type II supernovae (SNeII) with higher mass progenitors than the supernovae that produced the heavy r-process isotopes. In the context of our model, the light isotopes (e.g. {sup 96}Zr) are predominantly synthesized via charged-particle reactions in a high entropy wind environment, in which Hf isotopes are not produced. Collectively, our data indicates that CAIs sampled an excess of materials produced in a normal mass (12-25 M{sub ☉}) SNII.

  13. High resolution collinear resonance ionization spectroscopy of neutron-rich $^{76,77,78}$Cu isotopes

    CERN Document Server

    De Groote, Ruben Pieter

    In this work, nuclear magnetic dipole moments, electric quadrupole moments, nuclear spins and changes in the mean-squared charge radii of radioactive copper isotopes are presented. Reaching up to $^{78}$Cu ($Z=29$, $N=49$), produced at rates of only 10 particles per second, these measurements represent the most exotic laser spectroscopic investigations near the doubly-magic and very exotic $^{78}$Ni ($Z=28$,$N=50$) to date. This thesis outlines the technical developments and investigations of laser-atom interactions that were performed during this thesis. These developments were crucial for establishing a high-resolution, high sensitivity collinear resonance ionization spectroscopy experiment at ISOLDE, CERN. This thesis furthermore provides a detailed description of the analysis tools that were implemented and applied to extract the nuclear observables from the experimental data. The results were compared to several large-scale shell model calculations, and provide deep insight into the structure of $^{78}$N...

  14. Calculation of Generation Rate of Electron Ion Pairs Ionized by Radioactive Nuclide in Air

    Institute of Scientific and Technical Information of China (English)

    WU; Xiu-feng; ZHANG; Li-feng; LUO; Zhi-fu

    2015-01-01

    Alpha and beta nuclides are widely employed in industrial production and life for the ability of ionization.Static eliminator,ionization smoke detector,electron capture detector and radioactive lightning rod are some typical examples.Alpha/beta rays produce electrons by ionizing the air,and then the charge is transferred during

  15. Adsorption characteristics of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents.

    Science.gov (United States)

    Humelnicu, Doina; Dinu, Maria Valentina; Drăgan, Ecaterina Stela

    2011-01-15

    Adsorption features of UO(2)(2+) and Th(4+) ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model. The maximum experimental adsorption capacities were 328.32 mg Th(4+)/g composite, and 408.62 mg UO(2)(2+)/g composite. The overall adsorption tendency of CS/CPL composite toward UO(2)(2+) and Th(4+) radiocations in the presence of Cu(2+), Fe(2+) and Al(3+), under competitive conditions, followed the order: Cu(2+)>UO(2)(2+)>Fe(2+)>Al(3+), and Cu(2+)>Th(4+)>Fe(2+)>Al(3+), respectively. The negative values of Gibbs free energy of adsorption indicated the spontaneity of the adsorption of radioactive ions on both the CS/CPL composite and the cross-linked CS. The desorption level of UO(2)(2+) from the composite CS/CPL, by using 0.1M Na(2)CO(3), was around 92%, and that of Th(4+) ions, performed by 0.1M HCl, was around 85%, both values being higher than the desorption level of radiocations from the cross-linked CS, which were 89% and 83%, respectively.

  16. In-Source Laser Spectroscopy with the Laser Ion Source and Trap: First Direct Study of the Ground-State Properties of ^{217,219}Po

    Directory of Open Access Journals (Sweden)

    D. A. Fink

    2015-02-01

    Full Text Available A Laser Ion Source and Trap (LIST for a thick-target, isotope-separation on-line facility has been implemented at CERN ISOLDE for the production of pure, laser-ionized, radioactive ion beams. It offers two modes of operation, either as an ion guide, which performs similarly to the standard ISOLDE resonance ionization laser ion source (RILIS, or as a more selective ion source, where surface-ionized ions from the hot ion-source cavity are repelled by an electrode, while laser ionization is done within a radio-frequency quadrupole ion guide. The first physics application of the LIST enables the suppression of francium contamination in ion beams of neutron-rich polonium isotopes at ISOLDE by more than 1000 with a reduction in laser-ionization efficiency of only 20. Resonance ionization spectroscopy is performed directly inside the LIST device, allowing the study of the hyperfine structure and isotope shift of ^{217}Po for the first time. Nuclear decay spectroscopy of ^{219}Po is performed for the first time, revealing its half-life, α-to-β-decay branching ratio, and α-particle energy. This experiment demonstrates the applicability of the LIST at radioactive ion-beam facilities for the production and study of pure beams of exotic isotopes.

  17. Production of chemically reactive radioactive ion beams through on-line separation; Production de faisceaux d'ions radioactifs chimiquement reactifs par separation en ligne

    Energy Technology Data Exchange (ETDEWEB)

    Joinet, A

    2003-10-01

    The ISOL (isotope separation on line) allows the production of secondary radioactive ion beams through spallation or fragmentation or fission reactions that take place in a thick target bombarded by a high intensity primary beam. The challenge is to increase the intensity and purity of the radioactive beam. The optimization of the system target/source requires the right choice of material for the target by taking into account the stability of the material, its reactivity and the ionization method used. The target is an essential part of the system because radioactive elements are generated in it and are released more or less quickly. Tests have been made in order to select the best fitted material for the release of S, Se, Te, Ge and Sn. Materials tested as target filling are: ZrO{sub 2}, Nb, Ti, V,TiO{sub 2}, CeO{sub x}, ThO{sub 2}, C, ZrC{sub 4} and VC). Other molecules such as: COSe, COS, SeS, COTe, GeS, SiS, SnS have been studied to ease the extraction of recoil nuclei (Se, S, Te, Ge and Sn) produced inside the target.

  18. Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions

    CERN Document Server

    Xiao, Zhi-Gang; Chen, Lie-Wen; Li, Bao-An; Zhang, Ming; Xiao, Guo-Qing; Xu, Nu

    2013-01-01

    The high-density behavior of nuclear symmetry energy is among the most uncertain properties of dense neutron-rich matter. Its accurate determination has significant ramifications in understanding not only the reaction dynamics of heavy-ion reactions especially those induced by radioactive beams but also many interesting phenomena in astrophysics, such as the explosion mechanism of supernova and the properties of neutron stars. The heavy-ion physics community has devoted much effort during the last few years to constrain the high-density symmetry using various probes. In particular, the pion-/pion+ ratio has been most extensively studied both theoretically and experimentally. All models have consistently predicted qualitatively that the pion-/pion+ ratio is a sensitive probe of the high-density symmetry energy especially with beam energies near the pion production threshold. However, the predicted values of the pion-/pion+ ratio are still quite model dependent mostly because of the complexity of modeling pion ...

  19. Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany)]. E-mail: walter.assmann@lmu.de; Schubert, M. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany); Held, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany); Pichler, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Muenchen (Germany); Chill, A. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Kiermaier, S. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Schloesser, K. [Forschungszentrum Karlsruhe, 76021 Karlsruhe (Germany); Busch, H. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Schenk, K. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Streufert, D. [Acri.Tec GmbH, 16761 Hennigsdorf (Germany); Lanzl, I. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany)

    2007-04-15

    A biodegradable, {beta}-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the {beta}-emitter {sup 32}P. The influence of ion implantation and gamma sterilisation on degradation and {sup 32}P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (10{sup 15} ions/cm{sup 2}) and gamma dose (25 kGy) are found to be tolerable.

  20. Invariant-Mass Spectroscopy of Extremely Neutron-Rich Nuclei with SAMURAI at RIBF

    Science.gov (United States)

    Kondo, Yosuke; Nakamura, Takashi; Achouri, N. Lynda; Aumann, Thomas; Baba, Hidetada; Delaunay, Franck; Doornenbal, Pieter; Fukuda, Naoki; Gibelin, Julien; Hwang, Jongwon; Inabe, Naohito; Isobe, Tadaaki; Kameda, Daisuke; Kanno, Daiki; Kim, Sunji; Kobayashi, Nobuyuki; Kobayashi, Toshio; Kubo, Toshiyuki; Leblond, Sylvain; Lee, Jenny; Marqués, F. Miguel; Minakata, Ryogo; Motobayashi, Tohru; Murai, Daichi; Murakami, Tetsuya; Muto, Kotomi; Nakashima, Tomohiro; Nakatsuka, Noritsugu; Navin, Alahari; Nishi, Seijiro; Ogoshi, Shun; Orr, Nigel A.; Otsu, Hideaki; Sato, Hiromi; Satou, Yoshiteru; Shimizu, Yohei; Suzuki, Hiroshi; Takahashi, Kento; Takeda, Hiroyuki; Takeuchi, Satoshi; Tanaka, Ryuki; Togano, Yasuhiro; Tuff, Adam G.; Vandebrouck, Marine; Yoneda, Ken-ichiro

    A first experimental campaign for three physics programs using a spectrometer SAMURAI, which is newly constructed at RIBF at RIKEN, was performed in May 2012. In this campaign, the unbound nuclei 25O and 26O produced by one-proton removal reactions at ˜200 MeV/nucleon were investigated by means of invariant mass method. High statistics data compared with previous experiments could be obtained together with good particle identification resolution for outgoing heavy ion. Preliminary results show high performance of the SAMURAI spectrometer combined with high intense RI beams provided by RIBF.

  1. Introducing the Fission-Fusion Reaction Process: Using a Laser-Accelerated Th Beam to produce Neutron-Rich Nuclei towards the N=126 Waiting Point of the r Process

    CERN Document Server

    Habs, D; Gross, M; Allinger, K; Bin, J; Henig, A; Kiefer, D; Ma, W; Schreiber, J

    2010-01-01

    We propose to produce neutron-rich nuclei in the range of the astrophysical r process around the waiting point N=126 by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a polyethylene layer), where the light fission fragments of the beam fuse with the light fission fragments of the target. Via laser Radiation Pressure Acceleration using a high-intensity, short pulse laser, very efficiently bunches of solid state density of 232Th can be generated from a first Th production target, placed on a CH2 backing. Laser accelerated Th ions with about 7 MeV/u will pass through a thin polyethylene layer placed in front of a thicker second Th foil closely behind the first target and desintegrate into light and heavy fission fragments. In addition light ions (p,C) from the CH2 backing of the first Th target will be accelerated as well, inducing the fission process of 232Th also in the second Th target. The laser-accelerated ion bunches with solid state density, which are about 10^15 ti...

  2. Problems raised by radioactive ion acceleration in the SPIRAL project. Accelerator tuning and stabilisation; Problemes poses par l`acceleration d`ions radioactifs dans le project SPIRAL. Reglage et stabilisation de l`accelerateur

    Energy Technology Data Exchange (ETDEWEB)

    Boy, L. [Paris-6 Univ., 75 (France)

    1997-12-31

    This study is related to the SPIRAL project. This facility uses a cyclotron to accelerate radioactive ion beams produced in a thick target by the Grant Accelerateur National d`Ions Lourds primary beam. The low intensity of radioactive beams and the mixing of several species imply special tuning methods and associated diagnostics. Also, a cyclotron and the beam line will be used to switch from this tuning beam to the radioactive one. We present a theoretical study and a numerical simulation of the tuning of five radioactive beams using three different methods. the beam dynamic is performed through the injection beam line and the cyclotron up to the electrostatic deflector. Within the frame of these methods we have described all the SPIRAL beam diagnostics. Construction and test of a new low intensity diagnosis based on a plastic scintillator for phase measurement inside the cyclotron is described in details. (author). 63 refs.

  3. Fusion studies with low-intensity radioactive ion beams using an active-target time projection chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kolata, J.J., E-mail: jkolata@nd.edu [Physics Department, University of Notre Dame, Notre Dame, IN 46556 (United States); Howard, A.M. [Physics Department, University of Notre Dame, Notre Dame, IN 46556 (United States); Mittig, W. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Ahn, T. [Physics Department, University of Notre Dame, Notre Dame, IN 46556 (United States); Bazin, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Becchetti, F.D. [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States); Beceiro-Novo, S.; Chajecki, Z. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Febbrarro, M. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Fritsch, A.; Lynch, W.G. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Roberts, A. [Physics Department, University of Notre Dame, Notre Dame, IN 46556 (United States); Shore, A. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Torres-Isea, R.O. [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States)

    2016-09-11

    The total fusion excitation function for {sup 10}Be+{sup 40}Ar has been measured over the center-of-momentum (c.m.) energy range from 12 to 24 MeV using a time-projection chamber (TPC). The main purpose of this experiment, which was carried out in a single run of duration 90 h using a ≈100 particle per second (pps) {sup 10}Be beam, was to demonstrate the capability of an active-target TPC to determine fusion excitation functions for extremely weak radioactive ion beams. Cross sections as low as 12 mb were measured with acceptable (50%) statistical accuracy. It also proved to be possible to separate events in which charged particles were emitted from the fusion residue from those in which only neutrons were evaporated. The method permits simultaneous measurement of incomplete fusion, break-up, scattering, and transfer reactions, and therefore fully exploits the opportunities presented by the very exotic beams that will be available from the new generation of radioactive beam facilities.

  4. The development of the sup 1 sup 7 F beam at the Holifield radioactive ion beam facility

    CERN Document Server

    Welton, R F

    2002-01-01

    This report details some of the key technological developments employed at the Holifield Radioactive Ion Beam Facility (HRIBF) to produce beams of sup 1 sup 7 F using the sup 1 sup 6 O(d, n) sup 1 sup 7 F reaction. The oxide fiber target material used at the HRIBF is described and a comparison is made between the sup 1 sup 7 F yield achieved using light (Al) and heavy (Hf) metal oxide fibers. The development of the Kinetic Ejection Negative Ion Source (KENIS) employed in this work is also discussed along with the operational principles of the source. Finally, a detailed description of the HfO sub 2 target configuration used to produce 10 sup 7 -10 sup 8 sup 1 sup 7 F ions/s for over 850 hours of operation is provided. To date, seven nuclear physics experiments using accelerated beams of sup 1 sup 7 F and sup 1 sup 8 F produced using this apparatus have been performed over an energy range of 10-170 MeV.

  5. Reaction dynamics induced by the radioactive ion beam {sup 7}Be on medium-mass and heavy targets

    Energy Technology Data Exchange (ETDEWEB)

    Mazzocco, M., E-mail: marco.mazzocco@pd.infn.it; Stefanini, C.; Strano, E.; Torresi, D.; Lay, J. A.; Molini, P.; Soramel, F. [Dipartimento di Fisica e Astronomia, Università di Padova, via F. Marzolo 8, I-35131 Padova (Italy); INFN-Sezione di Padova, via F. Marzolo 8, I-35131 Padova (Italy); Boiano, A.; Parascandolo, C.; Pierroutsakou, D.; Di Meo, P. [INFN-Sezione di Napoli, via Cintia, I-80126, Napoli (Italy); Boiano, C. [INFN-Sezione di Milano, via Celoria 16, I-20133, Napoli (Italy); La Commara, M.; Sandoli, M.; Silvestri, R. [INFN-Sezione di Napoli, via Cintia, I-80126, Napoli (Italy); Dipartimento di Fisica, Università di Napoli “Federico II”, via Cintia, I-80126, Napoli (Italy); Manea, C.; Nicoletto, M. [INFN-Sezione di Padova, via F. Marzolo 8, I-35131 Padova (Italy); Acosta, L. [Departamento de Fìsica Aplicada, Universidad de Huelva, Campus de El Carmen, E-21071 Huelva (Spain); INFN-Sezione di Catania, via Santa Sofia 64, I-95123, Catania (Italy); Fernandez-Garcia, J. P. [INFN-Sezione di Catania, via Santa Sofia 64, I-95123, Catania (Italy); Glodariu, T. [National Institute for Physics and Nuclear Engineering (NIPNE), 30 Reactorului St., 077125 Magurele (Romania); and others

    2015-10-15

    We studied the reaction dynamics induced at Coulomb barrier energies by the weakly-bound Radioactive Ion Beam {sup 7}Be (S{sub α} = 1.586 MeV) on medium-mass ({sup 58}Ni) and heavy ({sup 208}Pb) targets. The experiments were performed at INFN-LNL (Italy), where a 2-3×10{sup 5} pps {sup 7}Be secondary beam was produced with the RIB in-flight facility EXOTIC. Charged reaction products were detected by means of high-granularity silicon detectors in rather wide angular ranges. The contribution presents an up-to-date status of the data analysis and theoretical interpretation for both systems.

  6. Charge breeding results and future prospects with electron cyclotron resonance ion source and electron beam ion source (invited).

    Science.gov (United States)

    Vondrasek, R; Levand, A; Pardo, R; Savard, G; Scott, R

    2012-02-01

    The Californium Rare Ion Breeder Upgrade (CARIBU) of the Argonne National Laboratory ATLAS facility will provide low-energy and reaccelerated neutron-rich radioactive beams for the nuclear physics program. A 70 mCi (252)Cf source produces fission fragments which are thermalized and collected by a helium gas catcher into a low-energy particle beam with a charge of 1+ or 2+. An electron cyclotron resonance (ECR) ion source functions as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. The final CARIBU configuration will utilize a 1 Ci (252)Cf source to produce radioactive beams with intensities up to 10(6) ions∕s for use in the ATLAS facility. The ECR charge breeder has been tested with stable beam injection and has achieved charge breeding efficiencies of 3.6% for (23)Na(8+), 15.6% for (84)Kr(17+), and 13.7% for (85)Rb(19+) with typical breeding times of 10 ms∕charge state. For the first radioactive beams, a charge breeding efficiency of 11.7% has been achieved for (143)Cs(27+) and 14.7% for (143)Ba(27+). The project has been commissioned with a radioactive beam of (143)Ba(27+) accelerated to 6.1 MeV∕u. In order to take advantage of its lower residual contamination, an EBIS charge breeder will replace the ECR charge breeder in the next two years. The advantages and disadvantages of the two techniques are compared taking into account the requirements of the next generation radioactive beam facilities.

  7. New developments on preparation of cooled and bunched Radioactive Ion beams at ISOL facilities the ISCOOL project and the rotating wall cooling

    CERN Document Server

    Podadera-Aliseda, I

    2006-01-01

    The future of physics research with radioactive isotopes is linked to the development of more accurate and specific experiments which will work with more exotic and energetic nuclei. Requirements from experiments are getting more and more stringent and represent a big challenge for the preparation of ion beams, since each one demands different optical specifications to optimize its setup and improve its results. This thesis focuses on the new developments achieved in preparation of RIB's (Radioactive Ion Beams) at ISOL facilities. Optical beam improvements based on cooling and bunching are the main points of the work. The design of a new general purpose second generation RFQCB (Radio Frequency ion Quadrupole Cooler and Buncher) for ISOLDE, the oldest ISOL facility, will be completely described. Nowadays, RFQCB's are one of the most important devices in the beam preparation stage thanks to the capacity to cool and bunch low-intensity ion beams quickly, easily and with great efficiency. The thesis will detail t...

  8. Laser Spectroscopy Study on the Neutron-Rich and Neutron-Deficient Te Isotopes

    CERN Multimedia

    2002-01-01

    We propose to perform laser spectroscopy measurements on the Te isotopes. This will give access to fundamental properties of the ground and rather long-lived isomeric states such as the change in the mean square charge radius ($\\delta\\langle$r$^2_c\\rangle$) and the nuclear moments. For these medium-mass isotopes, at this moment the optical resolution obtained with RILIS is not high enough to perform isotope shift measurements. Thus we will use the COMPLIS experimental setup which allows Resonant Ionization Spectroscopy (RIS) on laser desorbed atoms. The 5p$^{4}$ $^{3}$P$_{2} \\rightarrow$ 5p$^{3}$ 6s $^{3}$S$_{1}$ and 5p$^{4}$ $^{3}$P$_{2} \\rightarrow$ 5p$^{3}$ 6s $^{5}$S$_{2}$ optical transitions have been used to perform, on the stable Te isotopes, the tests required by the INTC committee. For this purpose stable-ion sources have been built and Te isotopes have been delivered as stable beams by the injector coupled to the COMPLIS setup. ISOLDE offers the opportunity for studying the Te isotope series over a ...

  9. Identification of neutron-rich new isotopes and their half-lives

    Energy Technology Data Exchange (ETDEWEB)

    Okano, Kotoyuki; Taniguchi, Akihiro [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1996-03-01

    Recently, some new isotopes such as {sup 156}Pm, {sup 155}Nd, {sup 154}Pr, {sup 152}Ce were identified using on-line isotope separation apparatus (KUR-ISOL). The half-lives of these isotopes were several seconds and those of other unknown nuclides are assumed to be around one second or extremely shorter. Detections of {sup 150}La, {sup 153}Ce, {sup 157}Nd etc. have not been succeeded by previous studies. In order to raise the efficiency for identification of short-lived nuclides, it seems essential to remarkably increase the beam strength of KUR-ISOL and to secure its safety operating. A mixed-gas jet method has been developed using a mixed gas of N{sub 2} and He and the beam strength increased by more than one digit. In addition, the exchange over time for gas was shortened by increasing the gas flow volume. Next, various aerosols were tested to select a stable and high efficient ion source and PbI{sub 2} aerosol was chosen as the most suitable one. A 4{pi}{beta}-{gamma}-coinsidence spectrometer with plastic scintillator of 1 mm in depth was constructed and simultaneous measurement for {beta}-ray and {gamma}-ray as well as measurement for a single spectre became possible. Thus identification of {sup 150}La was succeeded by those improvements of KUR-ISOL and the use of 4{pi}{beta}-{gamma}-coinsidence spectrometer. (M.N.)

  10. Theoretical and experimental studies of the neutron rich fission product yields at intermediate energies

    Directory of Open Access Journals (Sweden)

    Äystö J.

    2012-02-01

    Full Text Available A new method to measure the fission product independent yields employing the ion guide technique and a Penning trap as a precision mass filter, which allows an unambiguous identification of the nuclides is presented. The method was used to determine the independent yields in the proton-induced fission of 232Th and 238U at 25 MeV. The data were analyzed with the consistent model for description of the fission product formation cross section at the projectile energies up to 100 MeV. Pre-compound nucleon emission is described with the two-component exciton model using Monte Carlo method. Decay of excited compound nuclei is treated within time-dependent statistical model with inclusion of the nuclear friction effect. The charge distribution of the primary fragment isobaric chain was considered as a result of frozen quantal fluctuations of the isovector nuclear density. The theoretical predictions of the independent fission product cross sections are used for normalization of the measured fission product isotopic distributions.

  11. Medium-spin states of the neutron-rich 87,89Br isotopes: configurations and shapes

    Science.gov (United States)

    Nyakó, B. M.; Timár, J.; Csatlós, M.; Dombrádi, Zs; Krasznahorkay, A.; Kuti, I.; Sohler, D.; Tornyi, T. G.; Czerwiński, M.; Rząca-Urban, T.; Urban, W.; Bączyk, P.; Atanasova, L.; Balabanski, D. L.; Sieja, K.; Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T.; de France, G.; Simpson, G. S.; Ur, C. A.

    2016-06-01

    Medium-spin excited states of the neutron-rich 87Br and 89Br nuclei were observed and studied for the first time. They were populated in fission of 235U induced by the cold-neutron beam of the PF1B facility of the Institut Laue-Langevin, Grenoble. The measurement of γ radiation following fission has been performed using the EXILL array of Ge detectors. The observed level schemes were compared with results of large valence space shell model calculations. Both medium-spin level schemes consist of band-like structures, which can be understood as bands built on the πf 5/2, πp 3/2 and πg 9/2 configurations. Both nuclei have 5/2- ground state spin-parity contrary to the odd-mass Br isotopes containing fewer neutrons, which have 3/2- ground state spin-parity. On the basis of the properties of the πg 9/2 decoupled bands the deformations of the 87Br and 89Br fit to the systematics of nuclei in the region. 87Br is close to the vibrational limit, while 89Br is more rotational.

  12. Impact of new data for neutron-rich heavy nuclei on theoretical models for $r$-process nucleosynthesis

    CERN Document Server

    Kajino, Toshitaka

    2016-01-01

    Current models for the $r$ process are summarized with an emphasis on the key constraints from both nuclear physics measurements and astronomical observations. In particular, we analyze the importance of nuclear physics input such as beta-decay rates; nuclear masses; neutron-capture cross sections; beta-delayed neutron emission; probability of spontaneous fission, beta- and neutron-induced fission, fission fragment mass distributions; neutrino-induced reaction cross sections, etc. We highlight the effects on models for $r$-process nucleosynthesis of newly measured $\\beta$-decay half-lives, masses, and spectroscopy of neutron-rich nuclei near the $r$-process path. We overview r-process nucleosynthesis in the neutrino driven wind above the proto-neutron star in core collapse supernovae along with the possibility of magneto-hydrodynamic jets from rotating supernova explosion models. We also consider the possibility of neutron star mergers as an r-process environment. A key outcome of newly measured nuclear prope...

  13. Tetrahedral shapes of neutron-rich Zr isotopes from multidimensionally-constrained relativistic Hartree-Bogoliubov model

    CERN Document Server

    Zhao, Jie; Zhao, En-Guang; Zhou, Shan-Gui

    2016-01-01

    We develop a multidimensionally-constrained relativistic Hartree-Bogoliubov (MDC-RHB) model in which the pairing correlations are taken into account by making the Bogoliubov transformation. In this model, the nuclear shape is assumed to be invariant under the reversion of $x$ and $y$ axes, i.e., the intrinsic symmetry group is $V_4$ and all shape degrees of freedom $\\beta_{\\lambda\\mu}$ with even $\\mu$ are included self-consistently. The RHB equation is solved in an axially deformed harmonic oscillator basis. A separable pairing force of finite range is adopted in the MDC-RHB model. The potential energy curves of neutron-rich even-even Zr isotopes are calculated. The ground state shapes of $^{108-112}$Zr are predicted to be tetrahedral with both functionals DD-PC1 and PC-PK1 and $^{106}$Zr is also predicted to have a tetrahedral ground state with the functional PC-PK1. The tetrahedral ground states are caused by large energy gaps at $Z=40$ and $N=70$ when $\\beta_{32}$ deformation is included. Although the incl...

  14. Separation of Radioactive Elements Using Nitrogen Oxygen Donor Macrocyclic Ion Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Joong; Shim, Min Sook [Korea University, Seoul (Korea, Republic of); Kim, Jeong; Lee, Myung No [Seonam University, Namwon (Korea, Republic of)

    1997-07-01

    The study for the selective separation and recovery of Pd{sup 2+} ion lead to following results. The four kinds of stationary phase, SGB-NTOE, SGB-NTOT, SGB-NEOD, and SGB-NTOD, were synthesized to react NOTE, NTOT, NEOD, and NTOD with 3-glycidyloxypropyltrimethoxy silane and silica gel. Using these macrocycles, selective separation of Hg(II), Pt(II), and Pd(II) from alkali earth and transition metal ions were possible by column chromatography. Maximum separation capability was appeared in SGB-NTOT and it took 12 hours for complete separation of Pd{sup 2+} ion with the column which inner diameter was 24 cm. The results of the study for the selective separation of Cs{sup +} and Sr{sup 2+} are as follows: Sr{sup 2+} ion was effectively separated through liquid membrane with CR22BB and the relative transport ration of Sr{sup 2+}/Na{sup +} was 15. Cs{sup +} ion was effectively separated through liquid membrane with CR22BB(OH)Ph and the relative transport ration of Cs{sup +}/Na{sup +} was 3.4. 9 refs., 7 tabs., 15 figs. (author)

  15. Role of nuclear couplings in the inelastic excitation of weakly-bound neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Dasso, C.H. [Niels Bohr Institute, Copenhagen (Denmark); Lenzi, S.M.; Vitturi, A. [Universita di Padova (Italy)

    1996-12-31

    Much effort is presently devoted to the study of nuclear systems far from the stability line. Particular emphasis has been placed in light systems such as {sup 11}Li, {sup 8}B and others, where the very small binding energy of the last particles causes their density distribution to extend considerably outside of the remaining nuclear core. Some of the properties associated with this feature are expected to characterize also heavier systems in the vicinity of the proton or neutron drip lines. It is by now well established that low-lying concentrations of multipole strength arise from pure configurations in which a peculiar matching between the wavelength of the continuum wavefunction of the particles and the range of the weakly-bound hole states occurs. To this end the authors consider the break-up of a weakly-bound system in a heavy-ion collision and focus attention in the inelastic excitation of the low-lying part of the continuum. They make use of the fact that previous investigations have shown that the multipole response in this region is not of a collective nature and describe their excited states as pure particle-hole configurations. Since the relevant parameter determining the strength distributions is the binding energy of the last bound orbital they find it most convenient to use single-particle wavefunctions generated by a sperical square-well potential with characteristic nuclear dimensions and whose depth has been adjusted to give rise to a situation in which the last occupied neutron orbital is loosely-bound. Spin-orbit couplings are, for the present purpose, ignored. The results of this investigation clearly indicate that nuclear couplings have the predominant role in causing projectile dissociation in many circumstances, even at bombarding energies remarkably below the Coulomb barrier.

  16. Dynamical Dipole mode in heavy-ion fusion reactions by using stable and radioactive beams

    Directory of Open Access Journals (Sweden)

    Molini P.

    2011-10-01

    Full Text Available The existence of the dynamical dipole mode in the 192Pb composite system was investigated through the study of its prompt γ decay employing the 40Ca + 152Sm and 48Ca + 144Sm reactions at Elab =11 and 10.1 MeV/u, respectively. The γ-rays and light charged particles were detected in coincidence with evaporation residues and fission fragments. First results of this experiment show that the dynamical dipole mode survives in collisions involving heavier mass reaction partners than those studied previously. As a fast cooling mechanism on the fusion path, the prompt dipole γ radiation could be of interest for the synthesis of super-heavy elements through ”hot” fusion reactions. Furthermore, by using radioactive beams and the prompt γ radiation as a probe we could get information on the symmetry energy at sub-saturation densities.

  17. Evidence for a change in the nuclear mass surface with the discovery of the most neutron-rich nuclei with 17

    CERN Document Server

    Tarasov, O B; Amthor, A M; Baumann, T; Bazin, D; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Nettleton, A; Pereira, J; Portillo, M; Sherrill, B M; Stolz, A; Thoennessen, M

    2009-01-01

    The results of measurements of the production of neutron-rich nuclei by the fragmentation of a 76-Ge beam are presented. The cross sections were measured for a large range of nuclei including fifteen new isotopes that are the most neutron-rich nuclides of the elements chlorine to manganese (50-Cl, 53-Ar, 55,56-K, 57,58-Ca, 59,60,61-Sc, 62,63-Ti, 65,66-V, 68-Cr, 70-Mn). The enhanced cross sections of several new nuclei relative to a simple thermal evaporation framework, previously shown to describe similar production cross sections, indicates that nuclei in the region around 62-Ti might be more stable than predicted by current mass models and could be an indication of a new island of inversion similar to that centered on 31-Na.

  18. A test-bench for isotope separator on-line of Beijing radioactive ion-beam facility

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Bing, E-mail: tangb364@126.com; Ma, Ruigang; Huang, Qinghua; Chen, Lihua; Ma, Yingjun; Cui, Baoqun; Jiang, Weisheng

    2013-12-15

    Highlights: • The modular design makes the maintenance of target station easily. • The diagnosis for low intensity beam is solved. • A positive surface ion source has been developed. -- Abstract: A test-bench for isotope separator on-line of Beijing radioactive ion-beam facility (BRISOL) has been built in China Institute of Atomic Energy (CIAE). The test-bench consists of target station, charge exchange cell, mass separator, quadrupole, hexapole, multipole and beam diagnostic system. It is nearly the same configuration as the first stage of BRISOL and all these components will be used on the BRISOL. A series of experiments have been carried out on this test-bench, and the primary results showed that all the components worked well. A Li{sup +} beam has been generated from the positive surface-ionization source and its emittance and the transmission of the beam line have been measured. The design, construction and experimental results of this test-bench have been presented.

  19. Yield estimation of neutron-rich rare isotopes induced by 200 MeV/u {sup 132}Sn beams by using GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Won [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Min, Kyung Joo; Ham, Cheolmin [Department of Energy Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Park, Tae-Sun [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Hong, Seung-Woo, E-mail: swhong@skku.ac.kr [Department of Physics, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-04-15

    A so-called “two-step reaction scheme”, in which neutron-rich rare isotopes obtained from ISOL are post-accelerated and bombarded on a second target, is employed to estimate the production yields of exotic rare isotopes. The production yields of neutron-rich rare isotope fragments induced by 200 MeV/u {sup 132}Sn beams bombarded on a {sup 9}Be target are estimated with Monte Carlo code, GEANT4. To substantiate the use of GEANT4 for this study, benchmark calculations are done for 80 MeV/u {sup 59}Co, 95 MeV/u {sup 72}Zn, 500 MeV/u {sup 92}Mo, and 950 MeV/u {sup 132}Sn beams on the {sup 9}Be target. It is found that {sup 132}Sn beams can produce neutron-rich rare isotopes with 45 ⩽ Z ⩽ 50 more effectively than {sup 238}U beams at the same energy per nucleon.

  20. First-forbidden β -decay rates, energy rates of β -delayed neutrons and probability of β -delayed neutron emissions for neutron-rich nickel isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Nabi, Jameel-Un; Iftikhar, Zafar [GIK Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences, Khyber Pakhtunkhwa (Pakistan); Cakmak, Necla [Karabuek University, Department of Physics, Karabuek (Turkey)

    2016-01-15

    First-forbidden (FF) transitions can play an important role in decreasing the calculated half-lives specially in environments where allowed Gamow-Teller (GT) transitions are unfavored. Of special mention is the case of neutron-rich nuclei where, due to phase-space amplification, FF transitions are much favored. We calculate the allowed GT transitions in various pn-QRPA models for even-even neutron-rich isotopes of nickel. Here we also study the effect of deformation on the calculated GT strengths. The FF transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. Later we take into account deformation of nuclei and calculate GT + unique FF transitions, stellar β -decay rates, energy rate of β -delayed neutrons and probability of β -delayed neutron emissions. The calculated half-lives are in excellent agreement with measured ones and might contribute in speeding-up of the r-matter flow. (orig.)

  1. Coulomb excitation of neutron-rich nuclei between the N=40 and N=50 shell gaps using REX-ISOLDE and the Ge MINIBALL array

    CERN Multimedia

    2002-01-01

    We propose to perform Coulomb excitation experiments of neutron-rich nuclei in the vicinity of $^{68}$Ni towards $^{78}$Ni using the REX-ISOLDE facility coupled with the highly efficient MINIBALL array. Major changes in the structure of the atomic nucleus are expected around the N = 40 subshell closure. Recent B(E2) measurements suggested that $^{68}$Ni behaves like a doubly magic nucleus while neutron-rich Zn isotopes with N>38 exhibit a sudden increase of B(E2) values which may be the signature of deformation. We would like to check and test these predictions for neutron-rich nuclei in the vicinity of N = 40 and N = 50 shell closures like $^{72}$Zn, $^{74}$Zn, $^{76}$Zn, $^{68}$Ni, $^{70}$Ni. Our calculations show that an energy upgrade from 2.2 to 3 MeV/nucleon will be of crucial importance for a part of our study while some nuclei can still be very efficiently studied at an energy of 2.2 MeV/nucleon. Therefore, to perform our experiment in an efficient way, we request 21 shifts of beam time before the ene...

  2. Production cross sections from 82Se fragmentation as indications of shell effects in neutron-rich isotopes close to the drip-line

    CERN Document Server

    Tarasov, O B; Morrissey, D J; Amthor, A M; Bandura, L; Baumann, T; Bazin, D; Berryman, J S; Brown, B A; Chubarian, G; Fukuda, N; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Pereira, J; Sherrill, B M; Stolz, A; Sumithrarachichi, C; Thoennessen, M; Weisshaar, D

    2013-01-01

    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 126 neutron-rich isotopes of elements 11 <= Z <= 32 were scanned using an experimental approach of varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 22 <= Z <= 25 (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. The production cross sections are correlated with Qg systematics to reveal trends in the data. The results presented here confirm our previous result from a similar measurement using a 76Ge beam, and can be explained with a shell model that predicts a subshell closure at N = 34 around Z = 20. This is demonstrated by systematic trends and calculations with the Abrasion-Ablation model that ...

  3. Developments of the ISOLDE RILIS for radioactive ion beam production and the results of their application in the study of exotic mercury isotopes

    CERN Document Server

    Day Goodacre, Thomas; Marsh, Bruce

    This work centres around development and applications of the Resonance Ionization Laser Ion Source (RILIS) of the ISOLDE radioactive ion beam facility based at CERN. The RILIS applies step-wise resonance photo-ionization, to achieve an unparalleled degree of element selectivity, without compromising on ion source efficiency. Because of this, it has become the most commonly used ion source at ISOLDE, operating for up to 75% of ISOLDE experiments. In addition to its normal application as an ion source, the RILIS can be exploited as a spectroscopic tool for the study of nuclear ground state and isomer properties, by resolving the influence of nuclear parameters on the atomic energy levels of the ionization scheme. There are two avenues of development by which to widen the applicability of the RILIS: laser ionization scheme development, enabling new or more efficient laser ionized ion beams and the development of new laser-atom interaction regions. New ionization schemes for chromium, tellurium, germanium, mercu...

  4. 26Si excited states via one-neutron removal from a 27Si radioactive ion beam

    Science.gov (United States)

    Chen, J.; Chen, A. A.; Amthor, A. M.; Bazin, D.; Becerril, A. D.; Gade, A.; Galaviz, D.; Glasmacher, T.; Kahl, D.; Lorusso, G.; Matos, M.; Ouellet, C. V.; Pereira, J.; Schatz, H.; Smith, K.; Wales, B.; Weisshaar, D.; Zegers, R. G. T.

    2012-04-01

    A study of 26Si states by neutron removal from a fast radioactive beam of 27Si has been performed. A beam of 27Si of energy 84.3 MeV/nucleon impinged on a polypropylene foil (C3H6) of 180 mg/cm2 thickness. Deexcitation γ rays were detected with a highly segmented germanium detector array, in coincidence with the 26Si recoils, and the corresponding 26Si level energies were determined. In comparing our results to two previous γ-ray spectroscopic studies of 26Si level structures, we find good agreement with a recent measurement of the 12C(16O,2nγ)26Si reaction. Our results support the use of excitation energies from that study in helping determine the important resonance energies for the thermonuclear 25Al(p,γ)26Si reaction rate. We do not observe a bound state at 4093 keV reported in an earlier study of the 24Mg(3He,nγ)26Si reaction.

  5. Off-line production of a sup 7 Be radioactive ion beam

    CERN Document Server

    Gialanella, L; De Cesare, N; D'Onofrio, A; Romano, M; Campajola, L; Formicola, A; Fülöp, Z; Gyürky, G; Imbriani, G; Lubritto, C; Ordine, A; Roca, V; Rogalla, D; Rolfs, C; Russo, M; Sabbarese, C; Somorjai, E; Strieder, F; Terrasi, F; Trautvetter, H P

    2002-01-01

    A sup 7 Be ion beam of several particle pA at 8 MeV has been produced at the TTT3 tandem of the University 'Federico II' in Naples. The sup 7 Be nuclides were formed via the sup 7 Li(p,n) sup 7 Be reaction using a metallic Li target and an 11.4 MeV proton beam of 20 mu A intensity, delivered by the cyclotron in Debrecen. Methods of hot chemistry were used to extract the sup 7 Be nuclides from the Li matrix and to prepare the sup 7 Be cathodes for the ion sputter source of the tandem. Examples of sup 7 Be beam applications are given.

  6. Transportation of a radioactive ion beam for precise laser-trapping experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hirokazu; Inoue, T. [Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Ando, S.; Aoki, T.; Arikawa, H.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Köhler, L.; Sakamoto, K.; Uchiyama, A.; Sakemi, Y. [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan)

    2016-02-15

    Francium is the heaviest species among the alkali elements. Due to its properties, francium is said to be of advantage in measurements of tiny observations, such as atomic parity violation and electric dipole moment. Before executing experiments with francium, it must be produced artificially because it is one of the most unstable elements. We produced francium with the nuclear fusion reaction of an oxygen beam and gold target, ionized the produced francium through a thermal ionization process, and extracted the ion with electrostatic fields. However, the thermal ionization process is known to ionize not only an objective atom but also other atomic species. Therefore, a Wien filter was installed to analyze the composition of the ion beam and purify the beam. This allowed us to improve the beam purity from ∼10{sup −6} to ∼10{sup −3}.

  7. Induced radioactivity problem for high-power heavy-ion accelerators - Experimental investigation and longtime predictions

    CERN Document Server

    Fertman, A; Batyaev, V; Borisenko, N G; Cherkasov, A; Golubev, A A; Kantserov, V A; Karpikhin, E I; Koldobsky, A B; Lipatov, K A; Mulambetov, R D; Mulambetova, S V; Nekrasov, Y V; Prokourounov, M; Roudskoy, I; Sharkov, B Yu; Smirnov, G; Titarenko, Y E; Turtikov, V I; Zhivun, V M; Fehrenbacher, G; Hasse, R W; Hoffmann, Dieter H H; Hofmann, I; Mustafin, E R; Weyrich, K; Wieser, J; Mashnik, S; Barashenkov, V S; Gudima, K K; Nekrasov, Yu.; Titarenko, Yu.

    2002-01-01

    Preliminary results on activation and dose rates of thick copper targets irradiated with carbon ions at 0.1 GeV/A measured at the SIS-18 facility of GSI, Darmstadt and on residual nuclide production cross sections from thin copper and cobalt targets irradiated with carbon ions at 0.2 GeV/A measured at the TWAC facility of ITEP, Moscow are presented and compared with calculations by the Dubna version of the cascade model for nucleus-nucleus interactions realized in the code CASCADE and by the Los Alamos version of the Quark-Gluon String Model code LAQGSM merged with the Generalized Evaporation Model code GEM2 by Furihata, LAQGSM+GEM2.

  8. Self-consistent quasiparticle formulation of a multiphonon method and its application to the neutron-rich O20 nucleus

    Science.gov (United States)

    De Gregorio, G.; Knapp, F.; Lo Iudice, N.; Vesely, P.

    2016-04-01

    A Bogoliubov quasiparticle formulation of an equation-of-motion phonon method, suited for open-shell nuclei, is derived. Like its particle-hole version, it consists of deriving a set of equations of motions whose iterative solution generates an orthonormal basis of n -phonon states (n =0 ,1 ,2 ,... ), built of quasiparticle Tamm-Dancoff phonons, which simplifies the solution of the eigenvalue problem. The method is applied to the open-shell neutron-rich O20 for illustrative purposes. A Hartree-Fock-Bogoliubov canonical basis, derived from an intrinsic two-body optimized chiral Hamiltonian, is used to derive and solve the eigenvalue equations in a space encompassing a truncated two-phonon basis. The spurious admixtures induced by the violation of the particle number and the center-of-mass motion are eliminated to a large extent by a Gram-Schmidt orthogonalization procedure. The calculation takes into account the Pauli principle, is self-consistent, and is parameter free except for the energy cutoff used to truncate the two-phonon basis, which induces an increasing depression of the ground state through its strong coupling to the quasiparticle vacuum. Such a cutoff is fixed so as to reproduce the first 1- level. The two-phonon states are shown to enhance the level density of the low-energy spectrum, consistently with the data, and to induce a fragmentation of the E 1 strength which, while accounting for the very low E 1 transitions, is not sufficient to reproduce the experimental cross section in the intermediate energy region. This and other discrepancies suggest the need of including the three-phonon states. These are also expected to offset the action of the two phonons on the quasiparticle vacuum and, therefore, free the calculation from any parameter.

  9. Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

    Energy Technology Data Exchange (ETDEWEB)

    Mimura, H.; Akiba, K.; Onodera, Y.

    2002-02-26

    The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60Co, 88Y, 152Eu and 241Am, for thirty-four specimens of microcapsules in the presence of 10-1-10-4 M HNO3 were evaluated by the batch method. The distribution coefficient (Kd) of Cs+ above 103 cm3/g was obtained for the microcapsules enclosing CuFC or AMP. The Kd of Sr2+ around 102 cm3/g was obtained for the microcapsules containing clinoptilolite, antimonic acid, zeolite A, zeolite X or titanic acid. The microcapsules enclosing DEHPA exhibited relatively large Kd values of trivalent metal ions above 103 cm3/g; for example, the Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were 1.1x104, 7.5x10, 1.1x10, 1.0x104, 1.4x104, 3.4x103 cm3/g, respectively. The uptake rates of Cs+, Y3+, Eu3+ and Am3+ for this microcapsule were rather fast; the uptake percentage above 90% was obtained after 19 h-shaking and the uptake equilibrium was attained within 1 d. The AMP/CaALG exhibited high uptake ability for Cs+ even after irradiation of 188 kGy, and DEHPA/CaALG microcapsule had similar Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ ions before and after irradiation. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into gelling salt solution. The microcapsules enclosing inorganic ion-exchangers and extractants have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions.

  10. β -Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process

    Energy Technology Data Exchange (ETDEWEB)

    Lorusso, G.; Nishimura, S.; Xu, Z. Y.; Jungclaus, A.; Shimizu, Y.; Simpson, G. S.; Söderström, P. -A.; Watanabe, H.; Browne, F.; Doornenbal, P.; Gey, G.; Jung, H. S.; Meyer, B.; Sumikama, T.; Taprogge, J.; Vajta, Zs.; Wu, J.; Baba, H.; Benzoni, G.; Chae, K. Y.; Crespi, F. C. L.; Fukuda, N.; Gernhäuser, R.; Inabe, N.; Isobe, T.; Kajino, T.; Kameda, D.; Kim, G. D.; Kim, Y. -K.; Kojouharov, I.; Kondev, F. G.; Kubo, T.; Kurz, N.; Kwon, Y. K.; Lane, G. J.; Li, Z.; Montaner-Pizá, A.; Moschner, K.; Naqvi, F.; Niikura, M.; Nishibata, H.; Odahara, A.; Orlandi, R.; Patel, Z.; Podolyák, Zs.; Sakurai, H.; Schaffner, H.; Schury, P.; Shibagaki, S.; Steiger, K.; Suzuki, H.; Takeda, H.; Wendt, A.; Yagi, A.; Yoshinaga, K.

    2015-05-01

    The β -decay half-lives of 110 neutron-rich isotopes of the elements from Rb 37 to Sn 50 were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r -process calculations and reinforce the notion that the second (A≈130 ) and the rare-earth-element (A≈160 ) abundance peaks may result from the freeze-out of an (n,γ)⇌(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r -process events.

  11. Application of a radioactivity detector to the analysis of /sup 14/C-Carmoisine metabolites by ion-pair high-pressure liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Tragni, E.; Costa, L.G.; Marinovich, M.; Galli, C.L.

    1984-04-01

    /sup 14/C-Carmoisine was incubated under anaerobic conditions with a suspension of human feces. Analyses of the incubation medium by high-performance liquid chromatography (HPLC) attached to a radioactivity monitor (RAM) showed the same radioactivity profile as the urine and feces of rats dosed with the same azodye (200 mg kg-1; 25 microCi). The analyses were carried out with a 5 micron RP-C18 chromatographic column, using a linear gradient profile of different concentrations of water, methanol and an ion-pair reagent. Five radioactive peaks were present in the radiochromatogram , in addition to unmodified Carmoisine. The major peak retained half of the specific activity of Carmoisine, and exhibited the retention time and the u.v. spectrum of authentic naphthionic acid. The results demonstrate the value and the advantage of using the in vitro preparation as a model to detect and to identify the metabolites of similar synthetic azodyes used as food additives.

  12. The Role of Diffusion in ISOL Targets for the Production of radioactive Ions Beams

    CERN Document Server

    Beyer, Gerd-Jürgen; Novgorodov, A F; Ravn, H L

    2003-01-01

    On line isotope separation techniques (ISOL) for production of ion beams of short-lived radionuclides require fast separation of nuclear reaction products from irradiated target materials followed by a transfer into an ion source. As a first step in this transport chain the release of nuclear reaction products from refractory metals has been studied systematically and will be reviewed. High-energy protons (500-1000MeV) produce a large number of radionuclides in irradiated materials via the nuclear reactions spallation, fission and fragmentation. Foils and powder of Re, W, Ta, Hf, Mo, Nb, Zr, Y, Ti and C were irradiated with protons (600-1000MeV) at the Dubna synchrocyclotron and at the CERN PS-booster to produce different nuclear reaction products. The main topic of the paper is the determination of diffusion coefficients of the nuclear reaction products in the target matrix, data evaluation and a systematic interpretation of the data. The influence of the ionic radius of the diffusing species and the lattice...

  13. Nuclear reactions with 11C and 14O radioactive ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Fanqing [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has been developed at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. The current BEARS provides two RIBs: a 11C beam of up to 2x108 pps intensity on target and an 14O beam of up to 3x104 pps intensity. While the development of the 11C beam has been relatively easy, a number of challenges had to be overcome to obtain the 14O beam. The excellent 11C beam has been used to investigate several reactions. The first was the 197Au(11C,xn)208-xnAt reaction, which was used to measure excitation functions for the 4n to 8n exit channels. The measured cross sections were generally predicted quite well using the fusion-evaporation code HIVAP. Possible errors in the branching ratios of ?? decays from At isotopes as well as the presence of incomplete fusion reactions probably contribute to specific overpredictions. 15F has been investigated by the p(14O,p)14O reaction with the ERSIKTT technology. Several 14O+p runs have been performed. Excellent energy calibration was obtained using resonances from the p(14N,p)14N reaction in inverse kinematics, and comparing the results to those obtained earlier with normal kinematics. The differences between 14N+p and 14O+p in the stopping power function have been evaluated for better energy calibration. After careful calibration, the energy levels of 15F

  14. The Eurisol report. A feasibility study for a European isotope-separation-on-line radioactive ion beam facility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-12-01

    The Eurisol project aims at a preliminary design study of the next-generation European isotope separation on-line (ISOL) radioactive ion beam (RIB) facility. In this document, the scientific case of high-intensity RIBs using the ISOL method is first summarised, more details being given in appendix A. It includes: 1) the study of atomic nuclei under extreme and so-far unexplored conditions of composition (i.e. as a function of the numbers of protons and neutrons, or the so-called isospin), rotational angular velocity (or spin), density and temperature, 2) the investigation of the nucleosynthesis of heavy elements in the Universe, an important part of nuclear astrophysics, 3) a study of the properties of the fundamental interactions which govern the properties of the universe, and in particular of the violation of some of their symmetries, 4) potential applications of RIBs in solid-state physics and in nuclear medicine, for example, where completely new fields could be opened up by the availability of high-intensity RIBs produced by the ISOL method. The proposed Eurisol facility is then presented, with particular emphasis on its main components: the driver accelerator, the target/ion-source assembly, the mass-selection system and post-accelerator, and the required scientific instrumentation. Special details of these components are given in appendices B to E, respectively. The estimates of the costs of the Eurisol, construction and running costs, have been performed in as much details as is presently possible. The total capital cost (installation manpower cost included) of the project is estimated to be of the order of 630 million Euros within 20%. In general, experience has shown that operational costs per annum for large accelerator facilities are about 10% of the capital cost. (A.C.)

  15. Copper Ferrocyanide Functionalized Core-Shell Magnetic Silica Composites for the Selective Removal of Cesium Ions from Radioactive Liquid Waste.

    Science.gov (United States)

    Lee, Hyun Kyu; Yang, Da Som; Oh, Wonzin; Choi, Sang-June

    2016-06-01

    The copper ferrocyanide functionalized core-shell magnetic silica composite (mag@silica-CuFC) was prepared and was found to be easily separated from aqueous solutions by using magnetic field. The synthesized mag@silica-CuFC composite has a high sorption ability of Cs owing to its strong affinity for Cs as well as the high surface area of the supports. Cs sorption on the mag@silica-CuFC composite quickly reached the sorption equilibrium after 2 h of contact time. The effect of the presence of salts with a high concentration of up to 3.5 wt% on the efficiency of Cs sorption onto the composites was also studied. The maximum sorption ability was found to be maintained in the presence of up to 3.5 wt% of NaCl in the solution. Considering these results, the mag@silica-CuFC composite has great potential for use as an effective sorbent for the selective removal of radioactive Cs ions.

  16. Spectroscopic applications of the ISOLDE laser ion source

    CERN Document Server

    Sebastian, V; Fedosseev, V; Georg, U; Huber, G; Jading, Y; Jonsson, O; Köster, U; Koizumi, M; Kratz, K L; Kugler, E; Lettry, Jacques; Mishin, V I; Ravn, H L; Tamburella, C; Wöhr, A

    1998-01-01

    At the ISOLDE facility radioactive ion beams are produced via proton induced reactions in a target which is connected to a laser ion source. For beryllium a two step excitation scheme with laser light at wavelengths of lambda =235 nm and lambda =297 nm has been developed. Efficient laser ionization of beryllium was achieved with a new optical set-up using frequency tripling with two non-linear BBO crystals to generate laser light in the ultraviolet for the first excitation step. The second step was optimized to reach the 2p/sup 2 1/S/sub 0/ autoionizing state for high ionization efficiency. The isotope shift of /sup 7,9,10,11,12,14/Ba could be measured by tuning the wavelength of the first step. The laser ion source has also been used for the preparation of neutron-rich silver ion beams. Tuning the laser frequency of the first step it was possible to ionize selectively low- and high spin isomers of silver isotopes via the hyperfine structure. In both cases it was demonstrated that laser spectroscopy of exotic...

  17. Use of Radioactive Ion Beams for Biomedical Research 1. in vivo labelling of monoclonal antibodies with radio-lanthanides and $^{225}$Ac

    CERN Multimedia

    2002-01-01

    % IS330 \\\\ \\\\\\begin{enumerate} \\item The aim of this study was to contribute to developments of new radiopharmaceuticals for tumour diagnosis and therapy. CERN-ISOLDE is the leading facility in the world to provide radioactive ion beams with high selectivity, purity and intensity. Radioisotope production by spallation makes available a complete range of rare earth isotopes having as complete a diversity of types and energy of radiation, of half-life, and of ionic properties as one would wish. The availability of exotic nuclei, e.g. radionuclides of rare earth elements and $^{225}$Ac, opens new possibilities for the development of radiopharmaceuticals for diagnosis and therapy.\\\\ \\\\ \\item Two approaches were followed within the experimental program. The radioactive metal ions are bound either to bio-specific ligands (monoclonal antibodies or peptides) or to unspecific low molecular weight form. The aim of the experimental program is to evaluate relationships between physico-chemical parameters of the tracer m...

  18. Control of stopping position of radioactive ion beam in superfluid helium for laser spectroscopy experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X.F., E-mail: yangxf@ribf.riken.jp [School of Physics, Peking University, Chengfu Road, Haidian District, Beijing 100871 (China); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Furukawa, T. [Dept. of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Wakui, T. [Cyclotron and Radioisotope Center Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Imamura, K. [Dept. of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Tetsuka, H. [Dept. of Physics, Tokyo Gakugei University, 4-1-1 Nukuikitamachi, Koganei, Tokyo 184-8501 (Japan); Fujita, T. [Dept. of Physics, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Yamaguchi, Y. [Dept. of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Tsutsui, Y. [Dept. of Physics, Tokyo Gakugei University, 4-1-1 Nukuikitamachi, Koganei, Tokyo 184-8501 (Japan); Mitsuya, Y. [Dept. of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Ichikawa, Y. [Dept. of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo152-8551 (Japan); Ishibashi, Y. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Dept. of Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 (Japan); Yoshida, N.; Shirai, H. [Dept. of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo152-8551 (Japan); Ebara, Y.; Hayasaka, M. [Dept. of Physics, Tokyo Gakugei University, 4-1-1 Nukuikitamachi, Koganei, Tokyo 184-8501 (Japan); Arai, S.; Muramoto, S. [Dept. of Physics, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Hatakeyama, A. [Dept. of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Wada, M.; Sonoda, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); and others

    2013-12-15

    In order to investigate the structure of exotic nuclei with extremely low yields by measuring nuclear spins and moments, a new laser spectroscopy technique – “OROCHI” (Optical Radioisotopes Observation in Condensed Helium as Ion-catcher) has been proposed in recent years. The feasibility of this technique has been demonstrated by means of a considerable amount of offline and online studies of various atoms in superfluid helium. For in-situ laser spectroscopy of atoms in He II, trapping atoms in the observation region of laser is a key step. Therefore, a method which enables us to trap accelerated atoms at a precise position in He II is highly needed for performing experiment. In this work, a technique making use of a degrader, two plastic scintillators and a photon detection system is established for checking the stopping position of beam based on the LISE++ calculation. The method has been tested and verified by on-line experiments with the {sup 84,85,87}Rb beam. Details of the experimental setup, working procedure and testing results of this method are presented.

  19. Application of mixture design to optimize cementation of simulated spent radioactive ion exchange resins

    Institute of Scientific and Technical Information of China (English)

    GAN Xue-Ying; BAO Liang-Jin; LIN Mei-Qiong; James D.NAVRATIL

    2005-01-01

    The aim of this study was to assess the usefulness of a mixture design for spent resin immobilization in cement as well as to examine the cement-slag-ash system for spent resin solidification. Eighteen distinct combinations, consisting of Portland cement, blast furnace slag, fly ash, organic ion exchange resins and water, were selected by a mixture design computer procedure to compose representative experiment points. The measured properties of solidified forms resulting from the combinations included 28-day compressive strength, 42-day immersion strength,42-day immersion weight and slump. These data were fit to a mathematic model with the aid of Scheffe quadratic polynomial, and the effects of each ingredient on the measured properties were identified through an analysis of the response trace plots and contour plots. Utilization of an optimality function singled out an optimal combination comprising water=0.16(wt/wt), slag=0.21, ash=0.10, cement=0.27 and resin=0.26 from which the resulting response was 1 1MPa for the 28-day strength, 110mm for the slump and 5.4% for the 42-day increase in strength.

  20. Nuclear Structure at the Legnaro National Laboratories:. from High Intensity Stable to Radioactive Nuclear Beams

    Science.gov (United States)

    de Angelis, G.

    2007-04-01

    To understand the properties of a nucleus, apart from establishing the interaction between its components, it is necessary to determine the arrangement of the nucleons, i.e. the structure of a nucleus. So far our knowledge about the structure of nuclei is mostly limited to nuclei close to the valley of stability, or nuclei with a deficiency of neutrons, which can be produced in fusion-evaporation reactions with stable beams and stable targets. Future perspectives in nuclear structure rely on radioactive ion beams (RIB) as well as on high intensity beams of stable ions (HISB). A world wide effort is presently going on in order to built the next generation radioactive ion beam facilities like the FAIR and the EURISOL projects. The LNL are contributing to such development through the design study of the EURISOL project as well as through the design and construction of the intermediate facility SPES. Concerning the instrumentation, particularly powerful is the combination of large acceptance spectrometers with highly segmented γ-detector arrays. An example is the CLARA γ-ray detector array coupled with the PRISMA spectrometer at the Legnaro National Laboratories (LNL). The physics aims achievable with such device complement studies performed with current radioactive beam (RIB) facilities. With this set-up we have recently investigated the stability of the N=50 shell closure. Here the comparison of the experimental data with shell model calculations seems to indicate a persistence of the N=50 shell gap down to Z=31. Also the study of proton rich nuclei can strongly benefit from the use of high intensity stable beams using fusion evaporation reactions at energies close to the Coulomb barrier. Future perspectives at LNL are based on an increase in intensity as well as on the availability of heavy ion species. Moreover a new ISOL facility (SPES) dedicated to the production and acceleration of radioactive neutron rich species is now under development at LNL. Among the new

  1. Investigation of (3,3) resonance effects on the properties of neutron-rich double magic spherical finite nucleus, 132Sn, in the ground state and under compression

    Indian Academy of Sciences (India)

    Mohammed H E Abu-Sei'leek

    2011-04-01

    Within the framework of the radially constrained spherical Hartree–Fock (CSHF) approximation, the resonance effects of delta on the properties of neutron-rich double magic spherical nucleus 132Sn were studied. It was found that most of the increase in the nuclear energy generated under compression was used to create massive particles. For 132Sn nucleus under compression at 3.19 times density of the normal nuclear density, the excited nucleons to s were increased sharply up to 16% of the total number of constituents. This result is consistent with the values extracted from relativistic heavy-ion collisions. The single particle energy levels were calculated and their behaviours under compression were examined. A meaningful agreement was obtained between the results with effective Hamiltonian and that with the phenomenological shell model for the low-lying single-particle spectra. The results suggest considerable reduction in compressibility for the nucleus, and softening of the equation of state with the inclusion of s in the nuclear dynamics.

  2. Small-angle proton elastic scattering from the neutron-rich isotopes sup 6 He and sup 8 He, and from sup 4 He, at 0.7 GeV in inverse kinematics

    CERN Document Server

    Neumaier, S R; Andronenko, M N; Dobrovolsky, A V; Egelhof, P; Gavrilov, G E; Geissel, H; Irnich, H; Khanzadeev, A V; Korolev, G A; Lobodenko, A A; Münzenberg, G; Mutterer, M; Schwab, W; Seliverstov, D M; Suzuki, T; Timofeev, N A; Vorobyov, A A; Yatsoura, V I

    2002-01-01

    Absolute differential cross sections for elastic p sup 4 He, p sup 6 He and p sup 8 He small-angle scattering were measured in inverse kinematics with secondary sup 4 sup , sup 6 sup , sup 8 He-beams at an energy near 0.7 GeV/u. The experiment was performed using beams from the heavy-ion synchrotron SIS and the fragment separator FRS of GSI Darmstadt. The hydrogen-filled ionization chamber IKAR served simultaneously as a gas target and a detector for the recoil protons. Projectile scattering angles were measured with multi-wire tracking detectors. For proton scattering from the neutron-rich isotopes sup 6 He and sup 8 He, differential elastic-scattering cross sections d sigma/dt were deduced in the range 0.002<= parallel t parallel <=0.05 (GeV/c) sup 2 of the four-momentum transfer squared t. For elastic p sup 4 He scattering, the data obtained in the t-range 0.002<= parallel t parallel <=0.02 (GeV/c) sup 2 supplement the results from an earlier work performed in direct kinematics. From the differ...

  3. On the use of the (π-,K0) reaction on nuclear targets for the precise determination of the lifetime of the hydrogen hyperisotopes and other neutron-rich Λ-hypernuclei

    Science.gov (United States)

    Agnello, M.; Botta, E.; Bressani, T.; Bufalino, S.; Feliciello, A.

    2016-10-01

    Recent results reported by experiments with relativistic (heavy) ions have raised again the question whether the lifetime of H3Λ is very close to the lifetime of the free Λ hyperon. An updated careful analysis of all the existing experimental data shows that it is not, contrary to theoretical calculations. A similar conclusion can be drawn for the neighbor H4Λ. A clear cut high precision measurement performed with the straightforward method of time delay spectra is however lacking and it is eagerly needed. The idea of using the (π- ,K0) charge-exchange associated production reaction on targets of liquid 3,4He is discussed. A possible realization exploiting a large part of existing facilities at J-PARC is presented. A measurement with a 5% precision seems within reach with a modest effort and in a reasonable amount of time. The same set-up would also serve very well for the measurement of the lifetime of several neutron-rich Λ-hypernuclei of the p-shell, in particular of B12Λ. More importantly, the Weak Decay partial widths Γπ-, Γp and Γπ0 could be simultaneously determined in order to confirm their predicted strong variation with mass number, A, due to nuclear structure effects.

  4. Precision mass measurements of radioactive nuclei at JYFLTRAP

    CERN Document Server

    Rahaman, S; Eronen, T; Hager, U; Hakala, J; Jokinen, A; Kankainen, A; Moore, I D; Pentillä, H; Rinta-Antila, S; Rissanen, J; Saastamoinen, A; Sonoda, T; Weber, C; Äystö, J

    2007-01-01

    The Penning trap mass spectrometer JYFLTRAP was used to measure the atomic masses of radioactive nuclei with an uncertainty better than 10 keV. The atomic masses of the neutron-deficient nuclei around the N = Z line were measured to improve the understanding of the rp-process path and the SbSnTe cycle. Furthermore, the masses of the neutron-rich gallium (Z = 31) to palladium (Z = 46) nuclei have been measured. The physics impacts on the nuclear structure and the r-process paths are reviewed. A better understanding of the nuclear deformation is presented by studying the pairing energy around A = 100.

  5. Experimental study of neutron-rich nuclei near the N = 82 closed shell using the 4096Zr +50124Sn reaction with GASP and PRISMA-CLARA arrays

    Science.gov (United States)

    Rodríguez, W.; Torres, D. A.; Cristancho, F.; Medina, N. H.; Chapman, R.; Smith, J. F.; Mengoni, D.; Truesdale, V.; Grocutt, L.; Mulholland, K.; Kumar, V.; Hadinia, B.; Labiche, M.; Liang, X.; O'Donell, D.; Ollier, J.; Orlandi, R.; Smith, J. F.; Spohr, K. M.; Wady, P.; Wang, Z. M.; Gadea, A.; Ur, C. A.; Lenzi, S. M.; Capponi, L.; Michelangnoli, C.; Bazzacco, D.; Beghini, S.; Mǎrginean, R.; Mengoni, D.; Montagnoli, G.; Recchia, F.; Scarlassara, F.; Lunardi, S.; Kröll, T.; Napoli, D. R.; Corradi, L.; Fioretto, E.; de Angelis, G.; Mǎrginean, N.; Sahin, E.; Stefanini, A. M.; Valiente-Dobon, J. J.; Vedova, F. D.; Axiotis, M.; Martinez, T.; Szilner, S.; Freeman, S. J.; Smith, A. G.; Jones, G.; Thompson, N.; Pollarolo, G.

    2014-11-01

    In this contribution an experimental study of the deep-inelastic reaction 4096Zr +50124Sn at 530 MeV, using the GASP and PRISMA-CLARA arrays, is presented. The experiments populate a wealth of projectile-like and target-like binary fragments, in a large neutron-rich region around N ≥ 50 and Z ≈ 40. Preliminary results on the study of the yrast and near-yrast states for 95Nb will be shown, along with a comparison of the experimental yields obtained in the experiments.

  6. Schottky mass measurements of heavy neutron-rich nuclides in the element range $70\\leq Z\\leq 79$ at the ESR

    CERN Document Server

    Shubina, D; Litvinov, Yu A; Blaum, K; Brandau, C; Bosch, F; Carroll, J J; Casten, R F; Cullen, D M; Cullen, I J; Deo, A Y; Detwiler, B; Dimopoulou, C; Farinon, F; Geissel, H; Haettner, E; Heil, M; Kempley, R S; Kozhuharov, C; Knobel, R; Kurcewicz, J; Kuzminchuk, N; Litvinov, S A; Liu, Z; Mao, R; Nociforo, C; Nolden, F; Patyk, Z; Plass, W R; Prochazka, A; Reed, M W; Sanjari, M S; Scheidenberger, C; Steck, M; Stohlker, Th; Sun, B; Swan, T P D; Trees, G; Walker, P M; Weick, H; Winckler, N; Winkler, M; Woods, P J; Yamaguchi, T; Zhou, C

    2013-01-01

    Storage-ring mass spectrometry was applied to neutron-rich $^{197}$Au projectile fragments. Masses of $^{181,183}$Lu, $^{185,186}$Hf, $^{187,188}$Ta, $^{191}$W, and $^{192,193}$Re nuclei were measured for the first time. The uncertainty of previously known masses of $^{189,190}$W and $^{195}$Os nuclei was improved. Observed irregularities on the smooth two-neutron separation energies for Hf and W isotopes are linked to the collectivity phenomena in the corresponding nuclei.

  7. Shallow and diffuse spin-orbit potential for proton elastic scattering from neutron-rich helium isotopes at 71 MeV/nucleon

    CERN Document Server

    Sakaguchi, S; Aoi, N; Ichikawa, Y; Itoh, K; Itoh, M; Kawabata, T; Kawahara, T; Kondo, Y; Kuboki, H; Nakamura, T; Nakao, T; Nakayama, Y; Sakai, H; Sasamoto, Y; Sekiguchi, K; Shimamura, T; Shimizu, Y; Wakui, T

    2013-01-01

    Vector analyzing powers for proton elastic scattering from 8He at 71 MeV/nucleon have been measured using a solid polarized proton target operated in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a phenomenological optical model analysis is found to be significantly shallower and more diffuse than the global systematics of stable nuclei, which is an indication that the spin-orbit potential is modified for scattering involving neutron-rich nuclei. A close similarity between the matter radius and the root-mean-square radius of the spin-orbit potential is also identified.

  8. Beta-decay half-lives of new neutron-rich isotopes of Re, Os and Ir approaching the r-process path near N = 126

    Energy Technology Data Exchange (ETDEWEB)

    Kurtukian-Nieto, T.; Benlliure, J.; Casarejos, E.; Fernandez-Ordonez, M.; Pereira, J. [Universidade de Santiago de Compostela, Departamento de Fisica de Particulas, Santiago de Compostela (Spain); Schmidt, K.H.; Becker, F.; Borzov, I.N.; Henzlova, D.; Yordanov, O. [GSI-Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Audouin, L. [Institut de Physique Nucleaire, Orsay (France); Blank, B.; Giovinazzo, J.; Jurado, B. [CNRS/IN2P3-Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux-Gradignan, Gradignan (France); Farget, F. [GANIL, CAEN Cedex 5 (France); Langanke, K.; Martinez-Pinedo, G. [GSI-Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); TU Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany)

    2014-09-15

    Heavy neutron-rich nuclei close to N = 126 were produced by fragmentation of a 1A GeV {sup 208}Pb beam at the FRS at GSI. The β-decay half-lives of 7 nuclides have been determined using a novel numerical analysis method. The half-lives of {sup 202,199}Ir, {sup 200,199}Os and {sup 196}Re are reported for the first time. The comparison of the data with model calculations provides indications on the importance of first-forbidden transitions on the β-decay of nuclei around N = 126 and Z < 82. (orig.)

  9. 94 {beta}-Decay Half-Lives of Neutron-Rich 55Cs to 67Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.; Nishimura, S.; Lorusso, G.; Moller, P; Ideguchi, E; Regan, P. H.; Simpson, G. S.; Soderstrom, P. -A.; Walker, P. M.; Watanabe, H.; Kondev, F. G.

    2017-02-17

    The β-decay half-lives of 94 neutron-rich nuclei 144$-$151Cs, 146$-$154Ba, 148$-$156La, 150$-$158Ce, 153$-$160Pr, 156$-$162Nd, 159$-$163Pm, 160$-$166Sm, 161$-$168Eu, 165$-$170Gd, 166$-$172Tb, 169$-$173Dy, 172$-$175Ho, and two isomeric states 174mEr, 172mDy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β-decay half-lives are observed at neutron-number N = 97 for 58Ce, 59Pr, 60Nd, and 62Sm, and N = 105 for 63Eu, 64Gd, 65Tb, and 66Dy. Lastly, features in the data mirror the interplay between pairing effects and microscopic structure. r-process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system

  10. Effect of temperature on the durability of class C fly ash belite cement in simulated radioactive liquid waste: synergy of chloride and sulphate ions.

    Science.gov (United States)

    Guerrero, A; Goñi, S; Allegro, V R

    2009-06-15

    The durability of class C fly ash belite cement (FABC-2-W) in simulated radioactive liquid waste (SRLW) rich in a mixed sodium chloride and sulphate solution is presented here. The effect of the temperature and potential synergic effect of chloride and sulfate ions are discussed. This study has been carried out according to the Koch-Steinegger test, at the temperature of 20 degrees C and 40 degrees C during a period of 180 days. The durability has been evaluated by the changes of the flexural strength of mortar, fabricated with this cement, immersed in a simulated radioactive liquid waste rich in sulfate (0.5M), chloride (0.5M) and sodium (1.5M) ions--catalogued like severely aggressive for the traditional Portland cement--and demineralised water, which was used as reference. The reaction mechanism of sulphate, chloride and sodium ions with the mortar was evaluated by scanning electron microscopy (SEM), porosity and pore-size distribution, and X-ray diffraction (XRD). The results showed that the chloride binding and formation of Friedel's salt was inhibited by the presence of sulphate. Sulphate ion reacts preferentially with the calcium aluminate hydrates forming non-expansive ettringite which precipitated inside the pores; the microstructure was refined and the mechanical properties enhanced. This process was faster and more marked at 40 degrees C.

  11. Effect of temperature on the durability of class C fly ash belite cement in simulated radioactive liquid waste: Synergy of chloride and sulphate ions

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, A., E-mail: aguerrero@ietcc.csic.es [Eduardo Torroja Institute for Construction Science (CSIC), C/Serrano Galvache, 4, 28033 Madrid (Spain); Goni, S., E-mail: sgoni@ietcc.csic.es [Eduardo Torroja Institute for Construction Science (CSIC), C/Serrano Galvache, 4, 28033 Madrid (Spain); Allegro, V.R., E-mail: allegro@ietcc.csic.es [Eduardo Torroja Institute for Construction Science (CSIC), C/Serrano Galvache, 4, 28033 Madrid (Spain)

    2009-06-15

    The durability of class C fly ash belite cement (FABC-2-W) in simulated radioactive liquid waste (SRLW) rich in a mixed sodium chloride and sulphate solution is presented here. The effect of the temperature and potential synergic effect of chloride and sulfate ions are discussed. This study has been carried out according to the Koch-Steinegger test, at the temperature of 20 deg. C and 40 deg. C during a period of 180 days. The durability has been evaluated by the changes of the flexural strength of mortar, fabricated with this cement, immersed in a simulated radioactive liquid waste rich in sulfate (0.5 M), chloride (0.5 M) and sodium (1.5 M) ions - catalogued like severely aggressive for the traditional Portland cement - and demineralised water, which was used as reference. The reaction mechanism of sulphate, chloride and sodium ions with the mortar was evaluated by scanning electron microscopy (SEM), porosity and pore-size distribution, and X-ray diffraction (XRD). The results showed that the chloride binding and formation of Friedel's salt was inhibited by the presence of sulphate. Sulphate ion reacts preferentially with the calcium aluminate hydrates forming non-expansive ettringite which precipitated inside the pores; the microstructure was refined and the mechanical properties enhanced. This process was faster and more marked at 40 deg. C.

  12. New results from isochronous mass measurements of neutron-rich uranium fission fragments with the FRS-ESR-facility at GSI

    Science.gov (United States)

    Knöbel, R.; Diwisch, M.; Geissel, H.; Litvinov, Yu. A.; Patyk, Z.; Plaß, W. R.; Scheidenberger, C.; Sun, B.; Weick, H.; Bosch, F.; Boutin, D.; Chen, L.; Dimopoulou, C.; Dolinskii, A.; Franczak, B.; Franzke, B.; Hausmann, M.; Kozhuharov, C.; Kurcewicz, J.; Litvinov, S. A.; Matoš, M.; Mazzocco, M.; Münzenberg, G.; Nakajima, S.; Nociforo, C.; Nolden, F.; Ohtsubo, T.; Ozawa, A.; Stadlmann, J.; Steck, M.; Suzuki, T.; Walker, P. M.; Winkler, M.; Yamaguchi, T.

    2016-05-01

    Masses of uranium fission fragments have been measured with the FRagment Separator (FRS) combined with the Experimental Storage Ring (ESR) at GSI. A 410-415 MeV/u 238U projectile beam was fast extracted from the synchrotron SIS-18 with an average intensity of 109/spill. The projectiles were focused on a 1g/cm2 beryllium target at the entrance of the FRS to create neutron-rich isotopes via abrasion-fission. The fission fragments were spatially separated with the FRS and injected into the isochronous storage ring ESR for fast mass measurements without applying cooling. The Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without B ρ-tagging at the high-resolution dispersive central focal plane of the FRS. The evaluation has been done for the combined data sets from both experiments with a new method of data analysis. The use of a correlation matrix has provided experimental mass values for 23 different neutron-rich isotopes for the first time and 6 masses with improved values. The new masses were obtained for nuclides in the element range from Se to Ce. The applied analysis has given access even to rare isotopes detected with an intensity of a few atoms per week. The novel data analysis and systematic error determination are described and the results are compared with extrapolations of experimental values and theoretical models.

  13. In-beam γ -ray spectroscopy of the neutron-rich platinum isotope 200Pt toward the N =126 shell gap

    Science.gov (United States)

    John, P. R.; Valiente-Dobón, J. J.; Mengoni, D.; Modamio, V.; Lunardi, S.; Bazzacco, D.; Gadea, A.; Wheldon, C.; Rodríguez, T. R.; Alexander, T.; de Angelis, G.; Ashwood, N.; Barr, M.; Benzoni, G.; Birkenbach, B.; Bizzeti, P. G.; Bizzeti-Sona, A. M.; Bottoni, S.; Bowry, M.; Bracco, A.; Browne, F.; Bunce, M.; Camera, F.; Corradi, L.; Crespi, F. C. L.; Melon, B.; Farnea, E.; Fioretto, E.; Gottardo, A.; Grente, L.; Hess, H.; Kokalova, Tz.; Korten, W.; Kuşoǧlu, A.; Lenzi, S.; Leoni, S.; Ljungvall, J.; Menegazzo, R.; Michelagnoli, C.; Mijatović, T.; Montagnoli, G.; Montanari, D.; Napoli, D. R.; Podolyák, Zs.; Pollarolo, G.; Recchia, F.; Reiter, P.; Roberts, O. J.; Şahin, E.; Salsac, M.-D.; Scarlassara, F.; Sferrazza, M.; Söderström, P.-A.; Stefanini, A. M.; Szilner, S.; Ur, C. A.; Vogt, A.; Walshe, J.

    2017-06-01

    The neutron-rich nucleus 200Pt is investigated via in-beam γ -ray spectroscopy to study the shape evolution in the neutron-rich platinum isotopes towards the N =126 shell closure. The two-neutron transfer reaction 198Pt(82Se, 80Se)200Pt is used to populate excited states of 200Pt. The Advanced Gamma Ray Tracking Array (AGATA) demonstrator coupled with the PRISMA spectrometer detects γ rays coincident with the 80Se recoils, the binary partner of 200Pt. The binary partner method is applied to extract the γ -ray transitions and build the level scheme of 200Pt. The level at 1884 keV reported by Yates et al. [S. W. Yates, E. M. Baum, E. A. Henry, L. G. Mann, N. Roy, A. Aprahamian, R. A. Meyer, and R. Estep, Phys. Rev. C 37, 1889 (1988)] was confirmed to be at 1882.1 keV and assigned as the (61+) state. An additional γ ray was found and it presumably deexcites the (81+) state. The results are compared with state-of-the-art beyond mean-field calculations, performed for the even-even 190 -204Pt isotopes, revealing that 200Pt marks the transition from the γ -unstable behavior of lighter Pt nuclei towards a more spherical one when approaching the N =126 shell closure.

  14. New region of deformation in the neutron-rich {sup 60}{sub 24}Cr{sub 36} and {sup 62}{sub 24}Cr{sub 38}

    Energy Technology Data Exchange (ETDEWEB)

    Sorlin, O.; Donzaud, C.; Azaiez, F.; Bourgeois, C.; Chiste, V.; Guillemaud-Mueller, D.; Ibrahim, F.; Pougheon, F. [Institut de Physique Nucleaire, IN2P3-CNRS, F-91406 Orsay Cedex (France); Nowacki, F. [IReS, IN2P3-CNRS, Universite Louis Pasteur, BP 28, F-67037 Strasbourg Cedex (France); Angelique, J.C.; Grevy, S. [LPC, ISMRA, F-14050 Caen Cedex (France); Dlouhy, Z.; Mrasek, J. [Nuclear Physics Institute, AS CR, CZ 25068, Rez (Czech Republic); Kratz, K.L.; Pfeiffer, B. [Institut fuer Kernchemie, Universitaet Mainz, D-55128 Mainz (Germany); Lewitowicz, M.; de Oliveira Santos, F. [GANIL, B. P. 5027, F-14076 Caen Cedex (France); Lukyanov, S.M.; Penionzhkevich, Yu.E. [FLNR, JINR, 141980 Dubna, Moscow region (Russian Federation); Poves, A. [Departamento de Fisica Teorica, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Saint-Laurent, M.G.; Stanoiu, M.

    2003-01-01

    The neutron-rich nuclei {sub 23}{sup 60-63}V have been produced at GANIL via interactions of a 61.8A.MeV {sup 76}Ge beam with a {sup 58}Ni target. Beta-decay to {sub 24}{sup 60-63}Cr has been investigated using combined {beta}- and {gamma}-ray spectroscopy. Half-lives of the {sup 60-63}V nuclei have been determined, and the existence of a beta-decay isomer in the {sup 60}V nucleus is strongly supported. The observation of low-energy 2{sup +} states in {sup 60}Cr (646keV) and {sup 62}Cr (446keV) suggests that these isotopes are strongly deformed with {beta}{sub 2} {proportional_to}0.3. This is confirmed by shell model calculations which show the dominant influence of the intruder g and d orbitals to obtain low 2{sup +} energies in the neutron-rich Cr isotopes. (orig.)

  15. ${\\beta}$-decay studies of neutron-rich $^{61-70}$Mn isotopes with the new LISOL ${\\beta}$-decay setup

    CERN Multimedia

    Diriken, J V J

    2008-01-01

    The aim of this proposal is to gather new information that will serve as benchmark to test shell model calculations in the region below $^{68}$Ni, where proper residual interactions are still under development. More specifically, the ${\\beta}$-decay experiment of the $^{61-70}$Mn isotopes will highlight the development of collectivity in the Fe isotopes and its daughters. At ISOLDE, neutron-rich Mn isotopes are produced with a UC$_{x}$ target and selective laser ionization. These beams are particularly pure and reasonable yields are obtained for the neutron-rich short lived $^{61-70}$Mn isotopes. We propose to perform ${\\beta}$-decay studies on $^{61-70}$Mn utilizing the newly-developed "LISOL ${\\beta}$-decay setup", consisting of two MINIBALL cluster Ge detectors and a standard tape station. The use of digital electronics in the readout of these detectors enables us to perform a "slow correlation technique" which should indicate the possible existence of isomers in the daughter nuclei.

  16. New results from isochronous mass measurements of neutron-rich uranium fission fragments with the FRS-ESR-facility at GSI

    Energy Technology Data Exchange (ETDEWEB)

    Knoebel, R.; Litvinov, Yu.A.; Weick, H.; Bosch, F.; Boutin, D.; Dimopoulou, C.; Dolinskii, A.; Franczak, B.; Franzke, B.; Kozhuharov, C.; Kurcewicz, J.; Litvinov, S.A.; Matos, M.; Mazzocco, M.; Muenzenberg, G.; Nociforo, C.; Nolden, F.; Stadlmann, J.; Steck, M.; Winkler, M. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Diwisch, M. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Geissel, H.; Plass, W.R.; Scheidenberger, C.; Chen, L. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Patyk, Z. [National Centre for Nuclear Research - NCBJ Swierk, Warszawa (Poland); Sun, B. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); Hausmann, M. [Michigan State University, East Lansing, MI (United States); Nakajima, S.; Suzuki, T.; Yamaguchi, T. [Saitama University, Department of Physics, Saitama (Japan); Ohtsubo, T. [Niigata University, Department of Physics, Niigata (Japan); Ozawa, A. [University of Tsukuba, Institute of Physics, Ibaraki (Japan); Walker, P.M. [University of Surrey, Department of Physics, Guildford (United Kingdom)

    2016-05-15

    Masses of uranium fission fragments have been measured with the FRagment Separator (FRS) combined with the Experimental Storage Ring (ESR) at GSI. A 410-415 MeV/u {sup 238}U projectile beam was fast extracted from the synchrotron SIS-18 with an average intensity of 10{sup 9}/spill. The projectiles were focused on a 1g/cm{sup 2} beryllium target at the entrance of the FRS to create neutron-rich isotopes via abrasion-fission. The fission fragments were spatially separated with the FRS and injected into the isochronous storage ring ESR for fast mass measurements without applying cooling. The Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without B ρ-tagging at the high-resolution dispersive central focal plane of the FRS. The evaluation has been done for the combined data sets from both experiments with a new method of data analysis. The use of a correlation matrix has provided experimental mass values for 23 different neutron-rich isotopes for the first time and 6 masses with improved values. The new masses were obtained for nuclides in the element range from Se to Ce. The applied analysis has given access even to rare isotopes detected with an intensity of a few atoms per week. The novel data analysis and systematic error determination are described and the results are compared with extrapolations of experimental values and theoretical models. (orig.)

  17. Production of fast neutrons from deuteron beams in view of producing radioactive heavy ions beams; Etude de la production de neutrons rapides a partir de faisceaux de deutons en vue de la mise en oeuvre de faisceaux d'ions lourds radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, N

    2000-11-01

    This thesis is part of two research and development programmes for the study of neutron rich radioactive nuclear beam production. The technique is based on the ISOL method and can be summarized as follows. Fast neutrons are generated by the break-up of deuterons in a thick target. These neutrons irradiate a fissionable {sup 238}U target. The resulting fission products are extracted from the target, ionised, mass selected and post-accelerated. The aim of the thesis is to study the neutron angular and energetic distributions. After a bibliographical research to justify the choice of deuterons as the best projectile, we developed more specifically three points: - the extension of the activation detector method for neutron spectroscopy to a wide energy range (1 to 150 MeV), - the experimental measurement of neutron angular and energetic distributions produced by deuterons on thick targets. The deuteron energy ranges from 17 to 200 MeV and the thick targets were Be, C and U, - the realization of a code based on Serber's theory to predict the neutron distribution for any couple (deuteron energy-thick target). We conclude that for our application the most suitable target is C and the best deuteron energy is about 100 MeV. (author)

  18. Immobilization of ion exchange radioactive resins of the TRIGA Mark III nuclear reactor; Inmovilizacion de resinas de intercambio ionico radiactivas del reactor nuclear Triga Mark III

    Energy Technology Data Exchange (ETDEWEB)

    Garcia M, H.; Emeterio H, M.; Canizal S, C. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, C.P. 11801 Mexico D.F. (Mexico)

    2000-07-01

    This work has the objective to develop the process and to define the agglutinating material which allows the immobilization of the ion exchange radioactive resins coming from the TRIGA Mark III nuclear reactor contaminated with Ba-133, Co-60, Cs-137, Eu-152, and Mn-54 through the behavior analysis of different immobilization agents such as: bitumens, cement and polyester resin. According to the International Standardization the archetype samples were observed with the following tests: determination of free liquid, leaching, charge resistance, biodegradation, irradiation, thermal cycle, burned resistance. Generally all the tests were satisfactorily achieved, for each agent. Therefore, the polyester resin could be considered as the main immobilizing. (Author)

  19. The search for super-heavy ions; La quete des noyaux super-lourds

    Energy Technology Data Exchange (ETDEWEB)

    Grevy, St. [Grand Accelerateur National d' Ions Lourds (GANIL-LPC), IN2P3 - CNRS / Ensicaen et Universite, 14 - Caen (France); Stodel, Ch. [Grand Accelerateur National d' Ions Lourds (GANIL), CEA-CNRS-IN2P3, 14 - Caen (France)

    2003-07-01

    The authors present the search for heavy nuclei, they briefly draw a historical review of the production of heavy isotopes and then describe the means and possibilities the French GANIL (national great accelerator of heavy ions) facility offers. The different steps of the experimental process are described: production, selection, detection and identification. The production cross-sections are so weak that every parameter involved in the production process has to be optimized. It appears that the limit of our technological knowledge has been reached and unless an important technical step forward it seems impossible to go down below the pico-barn (10{sup -12}*10{sup -24} cm{sup 2}) for production cross-sections. The 2 remaining ways to improve the situation are: 1) to increase the intensity of the incident particle beam (today we have < 10{sup 13} pps), this implies that an important development about accelerators and ion sources has to be achieved, 2) the other way is to use radioactive ion beams, the excess of neutrons of the incident ion gives a better production rate and will allow us to reach the neutron-rich part of the stability island. (A.C.)

  20. Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon

    OpenAIRE

    Ohnishi, Tetsuya; Kubo*, Toshiyuki; Kusaka, Kensuke; Yoshida, Atsushi; Yoshida, Koichi; Ohtake, Masao; Fukuda, Naoki; Takeda, Hiroyuki; Kameda, Daisuke; Tanaka, Kanenobu; Inabe, Naohito; Yanagisawa, Yoshiyuki; Gono, Yasuyuki; Watanabe, Hiroshi; Otsu, Hideaki

    2010-01-01

    A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238U beam has been carried out at the RI Beam Factory at the RIKEN Nishina Center. Fission fragments were analyzed and identified by using the superconducting in-flight separator BigRIPS. We observed 45 new neutron-rich isotopes: 71Mn, 73,74Fe, 76Co, 79Ni, 81,82Cu, 84,85Zn, 87Ga, 90Ge, 95Se, 98Br, 101Kr, 103Rb, 106,107Sr, 108,109Y, 111,112Zr, 114,115Nb, 115,116,117Mo, 119,120Tc, 121,122,123,124Ru, 123,124,125,126Rh, 127,12...

  1. Study of fission barriers in neutron-rich nuclei using the (p,2p) reaction. Status of SAMURAI-experiment NP1306 SAMURAI14

    Energy Technology Data Exchange (ETDEWEB)

    Reichert, Sebastian [TU Munich (Germany); Collaboration: NP1306-SAMURAI14-Collaboration

    2015-07-01

    Violent stellar processes are currently assumed to be a major origin of the elements beyond iron and their abundances. The conditions during stellar explosions lead to the so called r-process in which the rapid capture of neutrons and subsequent β decays form heavier elements. This extension of the nuclei stops at the point when the repulsive Coulomb energy induces fission. Its recycling is one key aspect to describe the macroscopic structure of the r-process and the well known elemental abundance pattern. The RIBF at RIKEN is able to provide such neutron rich heavy element beams and a first test with the primary beam {sup 238}U was performed to understand the response of the SAMURAI spectrometer and detectors for heavy beams. The final goal is the definition of the fission barrier height with a resolution of 1 MeV (in σ) using the missing mass method using (p,2p) reactions in inverse kinematics.

  2. Shape coexistence in the N = 19 neutron-rich nucleus 31Mg explored by β-γ spectroscopy of spin-polarized 31Na

    Science.gov (United States)

    Nishibata, H.; Shimoda, T.; Odahara, A.; Morimoto, S.; Kanaya, S.; Yagi, A.; Kanaoka, H.; Pearson, M. R.; Levy, C. D. P.; Kimura, M.

    2017-04-01

    The structure of excited states in the neutron-rich nucleus 31Mg, which is in the region of the "island of inversion" associated with the neutron magic number N = 20, is studied by β-γ spectroscopy of spin-polarized 31Na. Among the 31Mg levels below the one neutron separation energy of 2.3 MeV, the spin values of all five positive-parity levels are unambiguously determined by observing the anisotropic β decay. Two rotational bands with Kπ = 1 /2+ and 1 /2- are proposed based on the spins and energies of the levels. Comparison on a level-by-level basis is performed between the experimental results and theoretical calculations by the antisymmetrized molecular dynamics (AMD) plus generator coordinate method (GCM). It is found that various nuclear structures coexist in the low excitation energy region in 31Mg.

  3. Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon

    CERN Document Server

    Ohnishi, Tetsuya; Kusaka, Kensuke; Yoshida, Atsushi; Yoshida, Koichi; Ohtake, Masao; Fukuda, Naoki; Takeda, Hiroyuki; Kameda, Daisuke; Tanaka, Kanenobu; Inabe, Naohito; Yanagisawa, Yoshiyuki; Gono, Yasuyuki; Watanabe, Hiroshi; Otsu, Hideaki; Baba, Hidetada; Ichihara, Takashi; Yamaguchi, Yoshitaka; Takechi, Maya; Nishimura, Shunji; Ueno, Hideki; Yoshimi, Akihiro; Sakurai, Hiroyoshi; Motobayashi, Tohru; Nakao, Taro; Mizoi, Yutaka; Matsushita, Masafumi; Ieki, Kazuo; Kobayashi, Nobuyuki; Tanaka, Kana; Kawada, Yosuke; Tanaka, Naoki; Deguchi, Shigeki; Satou, Yoshiteru; Kondo, Yosuke; Nakamura, Takashi; Yoshinaga, Kenta; Ishii, Chihiro; Yoshii, Hideakira; Miyashita, Yuki; Uematsu, Nobuya; Shiraki, Yasutsugu; Sumikama, Toshiyuki; Chiba, Junsei; Ideguchi, Eiji; Saito, Akito; Yamaguchi, Takayuki; Hachiuma, Isao; Suzuki, Takeshi; Moriguchi, Tetsuaki; Ozawa, Akira; Ohtsubo, Takashi; Famiano, Michael A; Geissel, Hans; Nettleton, Anthony S; Tarasov, Oleg B; Bazin, Daniel P; Sherrill, Bradley M; Manikonda, Shashikant L; Nolen, Jerry A

    2010-01-01

    A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238U beam has been carried out at the RI Beam Factory at the RIKEN Nishina Center. Fission fragments were analyzed and identified by using the superconducting in-flight separator BigRIPS. We observed 45 new neutron-rich isotopes: 71Mn, 73,74Fe, 76Co, 79Ni, 81,82Cu, 84,85Zn, 87Ga, 90Ge, 95Se, 98Br, 101Kr, 103Rb, 106,107Sr, 108,109Y, 111,112Zr, 114,115Nb, 115,116,117Mo, 119,120Tc, 121,122,123,124Ru, 123,124,125,126Rh, 127,128Pd, 133Cd, 138Sn, 140Sb, 143Te, 145I, 148Xe, and 152Ba.

  4. Spectroscopy of Neutron-Rich $^{168,170}$Dy: Yrast Band Evolution Close to the $N_{p}N_{n}$ Valence Maximum

    CERN Document Server

    Söderström, P A; Regan, P H; Algora, A; de Angelis, G; Ashley, S F; Aydin, S; Bazzacco, D; Casperson, R J; Catford, W N; Cederkäll, J; Chapman, R; Corradi, L; Fahlander, C; Farnea, E; Fioretto, E; Freeman, S J; Gadea, A; Gelletly, W; Gottardo, A; Grodner, E; He, C Y; Jones, G A; Keyes, K; Labiche, M; Liang, X; Liu, Z; Lunardi, S; Muarginean, N; Mason, P; Menegazzo, R; Mengoni, D; Montagnoli, G; Napoli, D; Ollier, J; Pietri, S; Podolyák, Z; Pollarolo, G; Recchia, F; Şahin, E; Scarlassara, F; Silvestri, R; Smith, J F; Spohr, K M; Steer, S J; Stefanini, A M; Szilner, S; Thompson, N J; Tveten, G M; Ur, C A; Valiente-Dobón, J J; Werner, V; Williams, S J; Xu, F R; Zhu, J Y

    2010-01-01

    The yrast sequence of the neutron-rich dysprosium isotope Dy-168 has been studied using multi-nucleon transfer reactions following the collision of a 460-MeV Se-82 beam and a Er-170 target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2+ and 4+ members of the previously measured ground state rotational band of Dy-168 was confirmed and the yrast band extended up to 10+. A tentative candidate for the 4+ to 2+ transition in Dy-170 was also identified. The data on this and lighter even-even dysprosium isotopes are interpreted in terms of Total Routhian Surface calculations and the evolution of collectivity approaching the proton-neutron valence product maximum is discussed.

  5. Discovery and cross-section measurement of neutron-rich isotopes in the element range from neodymium to platinum with the FRS

    Energy Technology Data Exchange (ETDEWEB)

    Kurcewicz, J., E-mail: j.kurcewicz@gsi.de [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Farinon, F.; Geissel, H. [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Justus-Liebig-Universitaet Giessen, 35392 Giessen (Germany); Pietri, S.; Nociforo, C. [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Prochazka, A. [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Justus-Liebig-Universitaet Giessen, 35392 Giessen (Germany); Weick, H.; Winfield, J.S. [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Estrade, A. [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Astronomy and Physics Department, Saint Mary' s University, Halifax, Nova Scotia B3H 3C3 (Canada); Allegro, P.R.P. [Institute of Physics, Universidade de Sao Paulo, CEP 05508-090 Cidade Universitaria, Sao Paulo (Brazil); Bail, A.; Belier, G. [CEA DAM DiF, 91290 Arpajon Cedex (France); Benlliure, J. [Universidad de Santiago de Compostela, E-15706 Santiago de Compostella (Spain); Benzoni, G. [INFN sezione di Milano, I-20133 Milano (Italy); Bunce, M.; Bowry, M. [Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH (United Kingdom); Caballero-Folch, R. [Universitat Politecnica de Catalunya, 08034 Barcelona (Spain); and others

    2012-10-31

    Using the high-resolution performance of the fragment separator FRS at GSI we have discovered 60 new neutron-rich isotopes in the atomic number range of 60 Less-Than-Or-Slanted-Equal-To Z Less-Than-Or-Slanted-Equal-To 78. The new isotopes were unambiguously identified in reactions with a {sup 238}U beam impinging on a Be target at 1 GeV/nucleon. The production cross-section for the new isotopes have been measured down to the pico-barn level and compared with predictions of different model calculations. For elements above hafnium fragmentation is the dominant reaction mechanism which creates the new isotopes, whereas fission plays a dominant role for the production of the new isotopes up to thulium.

  6. Direct mass measurements of neutron-rich $^{86}$Kr projectile fragments and the persistence of neutron magic number $N$ = 32 in Sc isotopes

    CERN Document Server

    Xu, Xing; Zhang, Yu-hu; Xu, Hu-shan; Shuai, Peng; Tu, Xiao-lin; Litvinov, Yuri A; Zhou, Xiao-hong; Sun, Bao-hua; Yuan, You-jin; Xia, Jia-wen; Yang, Jian-cheng; Blaum, KLaus; Chen, Rui-jiu; Chen, Xiang-cheng; Fu, Chao-yi; Ge, Zhuang; Hu, Zheng-guo; Huang, Wen-jia; Liu, Da-wei; Lam, Yi-hua; Ma, Xin-wen; Mao, Rui-shi; Uesaka, T; Xiao, Guo-ging; Xing, Yuan-ming; Yamaguchi, T; Yamaguchi, Y; Zeng, Qi; Yan, Xin-liang; Zhao, Hong-wei; Zhao, Tie-cheneg; Zhang, Wei; Zhan, Wen-long

    2016-01-01

    In this paper, we present direct mass measurements of neutron-rich $^{86}$Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of $^{52-54}$Sc nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, $^{53}$Sc and $^{54}$Sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number $N$ = 32 in Sc isotopes.

  7. Observation of isotonic symmetry for enhanced quadrupole collectivity in neutron-rich 62,64,66Fe isotopes at N=40

    CERN Document Server

    Rother, W; Iwasaki, H; Lenzi, S M; Starosta, K; Bazin, D; Baugher, T; Brown, B A; Crawford, H L; Fransen, C; Gade, A; Ginter, T N; Glasmacher, T; Grinyer, G F; Hackstein, M; Ilie, G; Jolie, J; McDaniel, S; Miller, D; Petkov, P; Pissulla, Th; Ratkiewicz, A; Ur, C A; Voss, P; Walsh, K A; Weisshaar, D; Zell, K -O

    2010-01-01

    The transition rates for the 2_{1}^{+} states in 62,64,66Fe were studied using the Recoil Distance Doppler-Shift technique applied to projectile Coulomb excitation reactions. The deduced E2 strengths illustrate the enhanced collectivity of the neutron-rich Fe isotopes up to N=40. The results are interpreted by the generalized concept of valence proton symmetry which describes the evolution of nuclear structure around N=40 as governed by the number of valence protons with respect to Z~30. The deformation suggested by the experimental data is reproduced by state-of-the-art shell calculations with a new effective interaction developed for the fpgd valence space.

  8. Half-life systematics across the N=126 shell closure: role of first-forbidden transitions in the β decay of heavy neutron-rich nuclei.

    Science.gov (United States)

    Morales, A I; Benlliure, J; Kurtukián-Nieto, T; Schmidt, K-H; Verma, S; Regan, P H; Podolyák, Z; Górska, M; Pietri, S; Kumar, R; Casarejos, E; Al-Dahan, N; Algora, A; Alkhomashi, N; Álvarez-Pol, H; Benzoni, G; Blazhev, A; Boutachkov, P; Bruce, A M; Cáceres, L S; Cullen, I J; Denis Bacelar, A M; Doornenbal, P; Estévez-Aguado, M E; Farrelly, G; Fujita, Y; Garnsworthy, A B; Gelletly, W; Gerl, J; Grebosz, J; Hoischen, R; Kojouharov, I; Kurz, N; Lalkovski, S; Liu, Z; Mihai, C; Molina, F; Mücher, D; Rubio, B; Shaffner, H; Steer, S J; Tamii, A; Tashenov, S; Valiente-Dobón, J J; Walker, P M; Wollersheim, H J; Woods, P J

    2014-07-11

    This Letter reports on a systematic study of β-decay half-lives of neutron-rich nuclei around doubly magic (208)Pb. The lifetimes of the 126-neutron shell isotone (204)Pt and the neighboring (200-202)Ir, (203)Pt, (204)Au are presented together with other 19 half-lives measured during the "stopped beam" campaign of the rare isotope investigations at GSI collaboration. The results constrain the main nuclear theories used in calculations of r-process nucleosynthesis. Predictions based on a statistical macroscopic description of the first-forbidden β strength reveal significant deviations for most of the nuclei with Nforbidden transitions reproduce more satisfactorily the trend in the measured half-lives for the nuclei in this region, where the r-process pathway passes through during β decay back to stability.

  9. Small-angle proton elastic scattering from the neutron-rich isotopes {sup 6}He and {sup 8}He, and from {sup 4}He, at 0.7 GeV in inverse kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Neumaier, S.R.; Alkhazov, G.D.; Andronenko, M.N.; Dobrovolsky, A.V.; Egelhof, P. E-mail: p.egelhof@gsi.de; Gavrilov, G.E.; Geissel, H.; Irnich, H.; Khanzadeev, A.V.; Korolev, G.A.; Lobodenko, A.A.; Muenzenberg, G.; Mutterer, M.; Schwab, W.; Seliverstov, D.M.; Suzuki, T.; Timofeev, N.A.; Vorobyov, A.A.; Yatsoura, V.I

    2002-12-30

    Absolute differential cross sections for elastic p {sup 4}He, p {sup 6}He and p {sup 8}He small-angle scattering were measured in inverse kinematics with secondary {sup 4,6,8}He-beams at an energy near 0.7 GeV/u. The experiment was performed using beams from the heavy-ion synchrotron SIS and the fragment separator FRS of GSI Darmstadt. The hydrogen-filled ionization chamber IKAR served simultaneously as a gas target and a detector for the recoil protons. Projectile scattering angles were measured with multi-wire tracking detectors. For proton scattering from the neutron-rich isotopes {sup 6}He and {sup 8}He, differential elastic-scattering cross sections d{sigma}/dt were deduced in the range 0.002{<=} parallel t parallel {<=}0.05 (GeV/c){sup 2} of the four-momentum transfer squared t. For elastic p {sup 4}He scattering, the data obtained in the t-range 0.002{<=} parallel t parallel {<=}0.02 (GeV/c){sup 2} supplement the results from an earlier work performed in direct kinematics. From the differential cross sections the integral elastic-scattering cross sections {sigma}{sub el}, the total cross sections {sigma}{sub tot}, and the total reaction cross sections {sigma}{sub r} for the proton-nucleus strong interaction were evaluated. The data obtained on d{sigma}/dt allow the radial matter distributions in the {sup 6}He and {sup 8}He nuclei to be determined and the corresponding root-mean-square matter radii to be deduced.

  10. Adsorption characteristics of UO{sub 2}{sup 2+} and Th{sup 4+} ions from simulated radioactive solutions onto chitosan/clinoptilolite sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Humelnicu, Doina, E-mail: doinah@uaic.ro [' Al. I. Cuza' University of Iasi, Faculty of Chemistry, Bd. 11 Carol I, 700506 Iasi (Romania); Dinu, Maria Valentina, E-mail: vdinu@icmpp.ro [' Petru Poni' Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi (Romania); Dragan, Ecaterina Stela, E-mail: sdragan@icmpp.ro [' Petru Poni' Institute of Macromolecular Chemistry, Aleea Grigore Ghica Voda 41A, 700487 Iasi (Romania)

    2011-01-15

    Adsorption features of UO{sub 2}{sup 2+} and Th{sup 4+} ions from simulated radioactive solutions onto a novel chitosan/clinoptilolite (CS/CPL) composite as beads have been investigated compared with chitosan cross-linked with epichlorohydrin. The effects of contact time, the initial metal ion concentration, sorbent mass and temperature on the adsorption capacity of the CS-based sorbents were investigated. The adsorption kinetics was well described by the pseudo-second order equation, and the adsorption isotherms were better fitted by the Sips model. The maximum experimental adsorption capacities were 328.32 mg Th{sup 4+}/g composite, and 408.62 mg UO{sub 2}{sup 2+}/g composite. The overall adsorption tendency of CS/CPL composite toward UO{sub 2}{sup 2+} and Th{sup 4+} radiocations in the presence of Cu{sup 2+}, Fe{sup 2+} and Al{sup 3+}, under competitive conditions, followed the order: Cu{sup 2+} > UO{sub 2}{sup 2+} > Fe{sup 2+} > Al{sup 3+}, and Cu{sup 2+} > Th{sup 4+} > Fe{sup 2+} > Al{sup 3+}, respectively. The negative values of Gibbs free energy of adsorption indicated the spontaneity of the adsorption of radioactive ions on both the CS/CPL composite and the cross-linked CS. The desorption level of UO{sub 2}{sup 2+} from the composite CS/CPL, by using 0.1 M Na{sub 2}CO{sub 3}, was around 92%, and that of Th{sup 4+} ions, performed by 0.1 M HCl, was around 85%, both values being higher than the desorption level of radiocations from the cross-linked CS, which were 89% and 83%, respectively.

  11. A perturbation of DC electric field caused by light ion adhesion to aerosols during the growth in seismic-related atmospheric radioactivity

    Directory of Open Access Journals (Sweden)

    V. M. Sorokin

    2007-01-01

    Full Text Available The influence of variations in conductivity and external electric current variations in the lower atmosphere on DC electric field over a seismic region is investigated. The external current is formed with the occurrence of convective upward transport of charged aerosols and their gravitational sedimentation in the atmosphere. This effect is related with the occurrence of ionization source due to seismic-related emanation of radon and other radioactive elements into the lower atmosphere. An increase in atmosphere radioactivity level results in the appearance of additional sources of ionization, and altitude dependence of the ion formation rate is calculated. Ionization source varies the atmospheric conductivity and the external current through appearance of ions with equilibrium number density and their adhesion to aerosols. We have calculated the perturbation of conductivity and external electric current as a function of altitude. Variation of conductivity and external current in the lower atmosphere leads to a perturbation of electric current which flows in the global atmosphere-ionosphere circuit. Finally, perturbations of DC electric field both on the Earth's surface and in the ionosphere are estimated.

  12. Nuclear breathing mode in neutron-rich Nickel isotopes: sensitivity to the symmetry energy and the role of the continuum

    CERN Document Server

    Piekarewicz, J

    2014-01-01

    In this new era of radioactive beam facilities, the discovery of novel modes of excitation in nuclei far away from stability represents an area of intense research activity. In addition, these modes of excitation appear to be sensitive to the uncertain density dependence of the symmetry energy. We study the emergence, evolution, and nature of both the soft and giant isoscalar monopole modes as a function of neutron excess in three unstable Nickel isotopes: 56Ni, 68Ni, and 78Ni. The distribution of isoscalar monopole strength is computed in a relativistic random-phase approximation using several accurately calibrated effective interactions. In particular, a non-spectral Green's function approach is adopted that allows for an exact treatment of the continuum without any reliance on discretization. The discretization of the continuum is neither required nor admitted. In the case of 56Ni, the lack of low-energy strength results in a direct correlation between the centroid energy of the giant monopole resonance an...

  13. Development of long-lived radionuclide partitioning technology - Preparation of ion exchanges for selective separation of radioactive elements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Joong; Jeong, Hae In; Shim, Min Sook [Korea University, Seoul (Korea, Republic of); Kim, Jeong [Seonam University, Namwon (Korea, Republic of)

    1995-07-01

    Ion exchanger contained nitrogen-oxygen donor macrocyclic units was synthesized, and immobilization process was carried out by adsorption of the exchanger to silica gel. The binding constants were measured with acid concentration. From the binding constants, selectivity for Pt(II) ion and acid concentration of eluents were determined. The most optimum conditions for the separation were also determined from investigating the effects of amount of immobile phase and column length. And liarit aza-crown ethers were synthesized and selectively separated Cs/Sr ion from mixed metal solution. 37= refs., 24 tabs., 40 figs. (author)

  14. Precision mass measurements of very short-lived, neutron-rich Na isotopes using a radiofrequency spectrometer

    CERN Document Server

    Lunney, M D; Doubre, H; Henry, S; Monsanglant, C; De Saint-Simon, M; Thibault, C; Toader, C F; Borcea, C; Bollen, G

    2001-01-01

    Mass measurements of high precision have been performed on sodium isotopes out to $^{30}$Na using a new technique of radiofrequency excitation of ion trajectories in a homogeneous magnetic field. This method, especially suited to very short-lived nuclides, has allowed us to significantly reduce the uncertainty in mass of the most exotic Na isotopes: a relative error of 5x10$^{-7}$ was achieved for $^{28}$Na having a half-life of only 30.5 ms and 9x10$^{-7}$ for the weakly produced $^{30}$Na. Verifying and minimizing binding energy uncertainties in this region of the nuclear chart is important for clarification of a long standing problem concerning the strength of the $N$=20 magic shell closure. These results are the fruit of the commissioning of the new experimental program Mistral.

  15. Management of radioactive waste: A review

    Directory of Open Access Journals (Sweden)

    Luis Paulo Sant'ana

    2016-06-01

    Full Text Available The issue of disposal of radioactive waste around the world is not solved by now and the principal reason is the lack of an efficient technologic system. The fact that radioactive waste decays of radioactivity with time are the main reasons for setting nuclear or radioactive waste apart from the other common hazardous wastes management. Radioactive waste can be classified according to the state of matter and level of radioactivity and this classification can be differently interpreted from country to country. Furthermore, microbiological procedures, plasma vitrification process, chemical precipitation, ion exchange, evaporation and reverse osmosis are strategies used for the treatment of radioactive wastes. The major challenge is to manage these radioactive substances after being used and discharged. This report brings data from the literature published worldwide from 2009 to 2014 on radioactive waste management studies and it covers production, classification and management of radioactive solid, liquid and gas waste.

  16. Coulomb excitation of neutron-rich$^{28,29,30}$Na nuclei with MINIBALL at REX-ISOLDE: Mapping the borders of the island of inversion

    CERN Multimedia

    Butler, P; Cederkall, J A; Reiter, P; Wiens, A; Blazhev, A A; Kruecken, R; Voulot, D; Kalkuehler, M; Wadsworth, R; Gernhaeuser, R A; Hess, H E; Holler, A; Finke, F; Leske, J; Huyse, M L; Seidlitz, M

    We propose to study the properties of neutron-rich nuclei $^{28,29,30}$Na via Coulomb excitation experiments using the REX-ISOLDE facility coupled with the highly efficient MINIBALL array. Reliable B(E2,0$^{+}$ $\\rightarrow$ 2$^{+}$) values for $^{30,32}$Mg were obtained at ISOLDE. Together with recent new results on $^{31}$Mg, collective and single particle properties are probed for Z=12 at the N=20 neutron closed shell, the 'island of inversion'. We would like to extend this knowledge to the neighbouring $^{28,29,30}$Na isotopes where a different transition from the usual filling of the neutron levels into the region with low lying 2p-2h cross shell configurations is predicted by theory. Detailed theoretical predictions on the transition strength in all three Na nuclei are awaiting experimental verification and are the subject of this proposal. At REX beam energies of 3.0 MeV /nucleon the cross-sections for Coulomb excitation are sufficient. Moreover the results from the close-by $^{30,31,32}$Mg nuclei de...

  17. Large-scale shell-model calculations for unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes

    CERN Document Server

    Togashi, Tomoaki; Utsuno, Yutaka; Otsuka, Takaharu; Honma, Michio

    2014-01-01

    We investigate unnatural-parity high-spin states in neutron-rich Cr and Fe isotopes using large-scale shell-model calculations. These shell-model calculations are carried out within the model space of $fp$-shell + $0g_{9/2}$ + $1d_{5/2}$ orbits with the truncation allowing $1\\hbar\\omega$ excitation of a neutron. The effective Hamiltonian consists of GXPF1Br for $fp$-shell orbits and $V_{\\rm MU}$ with a modification for the other parts. The present shell-model calculations can describe and predict the energy levels of both natural- and unnatural-parity states up to the high-spin states in Cr and Fe isotopes with $N\\le35$. The total energy surfaces present the prolate deformations on the whole and indicate that the excitation of one neutron into the $0g_{9/2}$ orbit plays the role of enhancing the prolate deformation. For the positive(unnatural)-parity states in odd-mass Cr and Fe isotopes, their energy levels and prolate deformations indicate the decoupling limit of the particle-plus-rotor model. We have found...

  18. Identification and Decay Studies of New, Neutron-Rich Isotopes of Bismuth, Lead and Thallium by means of a Pulsed Release Element Selective Method

    CERN Multimedia

    Mills, A; Kugler, E; Van duppen, P L E; Lettry, J

    2002-01-01

    % IS354 \\\\ \\\\ It is proposed to produce, identify and investigate at ISOLDE new, neutron-rich isotopes of bismuth, lead and thallium at the mass numbers A=215 to A=218. A recently tested operation mode of the PS Booster-ISOLDE complex, taking an advantage of the unique pulsed proton beam structure, will be used together with a ThC target in order to increase the selectivity. The decay properties of new nuclides will be studied by means of $\\beta$-, $\\gamma$- and X- ray spectroscopy methods. The expected information on the $\\beta$-half-lives and excited states will be used for testing and developing the nuclear structure models ``south-east'' of $^{208}$Pb, and will provide input data for the description of the r-process path at very heavy nuclei. The proposed study of the yields and the decay properties of those heavy nuclei produced in the spallation of $^{232}$Th by a 1~GeV proton beam contributes also the data necessary for the simulations of a hybrid accelerator-reactor system.

  19. Time-of-flight mass measurements of neutron-rich chromium isotopes up to N = 40 and implications for the accreted neutron star crust

    CERN Document Server

    Meisel, Z; Ahn, S; Bazin, D; Brown, B A; Browne, J; Carpino, J F; Chung, H; Cyburt, R H; Estradé, A; Famiano, M; Gade, A; Langer, C; Matoš, M; Mittig, W; Montes, F; Morrissey, D J; Pereira, J; Schatz, H; Schatz, J; Scott, M; Shapira, D; Sieja, K; Smith, K; Stevens, J; Tan, W; Tarasov, O; Towers, S; Wimmer, K; Winkelbauer, J R; Yurkon, J; Zegers, R G T

    2016-01-01

    We present the mass excesses of 59-64Cr, obtained from recent time-of-flight nuclear mass measurements at the National Superconducting Cyclotron Laboratory at Michigan State University. The mass of 64Cr is determined for the first time, with an atomic mass excess of -33.48(44) MeV. We find a significantly different two-neutron separation energy S2n trend for neutron-rich isotopes of chromium, removing the previously observed enhancement in binding at N=38. Additionally, we extend the S2n trend for chromium to N=40, revealing behavior consistent with the previously identified island of inversion in this region. We compare our results to state-of-the-art shell-model calculations performed with a modified Lenzi-Nowacki-Poves-Sieja interaction in the fp shell, including the g9/2 and d5/2 orbits for the neutron valence space. We employ our result for the mass of 64Cr in accreted neutron star crust network calculations and find a reduction in the strength and depth of electron-capture heating from the A=64 isobaric...

  20. Half-lives and branchings for {\\beta}-delayed neutron emission for neutron-rich Co-Cu isotopes in the r-process

    CERN Document Server

    Hosmer, P; Aprahamian, A; Arndt, O; Clement, R R C; Estrade, A; Farouqi, K; Kratz, K -L; Liddick, S N; Lisetskiy, A F; Mantica, P F; Möller, P; Mueller, W F; Montes, F; Morton, A C; Ouellette, M; Pellegrini, E; Pereira, J; Pfeiffer, B; Reeder, P; Santi, P; Steiner, M; Stolz, A; Tomlin, B E; Walters, W B; Wöhr, A; 10.1103/PhysRevC.82.025806

    2010-01-01

    The {\\beta} decays of very neutron-rich nuclides in the Co-Zn region were studied experimentally at the National Superconducting Cyclotron Laboratory using the NSCL {\\beta}-counting station in conjunction with the neutron detector NERO. We measured the branchings for {\\beta}-delayed neutron emission (Pn values) for 74Co (18 +/- 15%) and 75-77Ni (10 +/- 2.8%, 14 +/- 3.6%, and 30 +/- 24%, respectively) for the first time, and remeasured the Pn values of 77-79Cu, 79,81Zn, and 82Ga. For 77-79Cu and for 81Zn we obtain significantly larger Pn values compared to previous work. While the new half-lives for the Ni isotopes from this experiment had been reported before, we present here in addition the first half-life measurements of 75Co (30 +/- 11 ms) and 80Cu (170+110 -50 ms). Our results are compared with theoretical predictions, and their impact on various types of models for the astrophysical rapid neutron-capture process (r-process) is explored. We find that with our new data, the classical r-process model is bet...

  1. Erratum to 'Beta decay half-lives of neutron rich Ti-Co isotopes around N=40' [Nucl. Phys. A 660 (1999) 3-19

    CERN Document Server

    Sorlin, O; Axelsson, L; Belleguic, M; Béraud, R; Borcea, C; Canchel, G; Chabanat, E; Daugas, J M; Emsallem, A; Girod, M; Guillemaud-Müller, D; Kratz, K L; Leenhardt, S; Lewitowicz, M; Longour, C; López, M J; De Oliveira-Santos, F; Petizon, L; Pfeiffer, B; Pougheon, F; Saint-Laurent, M G; Sauvestre, J E

    2000-01-01

    The neutron-rich sup 5 sup 7 sup - sup 5 sup 9 Ti, sup 5 sup 9 sup - sup 6 sup 2 V, sup 6 sup 1 sup - sup 6 sup 4 Cr, sup 6 sup 3 sup - sup 6 sup 6 Mn, sup 6 sup 5 sup - sup 6 sup 8 Fe, sup 6 sup 7 sup - sup 7 sup 0 Co have been produced at GANIL via interactions of a 60.4 MeV/u sup 8 sup 6 Kr sup 3 sup 4 sup + with a sup 5 sup 8 Ni target. They have been separated by the doubly achromatic spectrometer LISE3. Beta-decay half-lives have been determined for all produced nuclei, and subsequent gamma-rays have been observed for the most efficiently produced nuclei. The measured half-lives of vanadium and chromium isotopes are compared to QRPA calculations using ground states deformations from the FRDM or ETFSI models. In an astrophysical context, the short half-lives of sup 5 sup 8 Ti and sup 6 sup 4 Cr indicate that these nuclei are potential r-process progenitors, after beta-decay, of sup 5 sup 8 Fe and sup 6 sup 4 Ni in certain inclusions of meteorites.

  2. Study of single particle properties of neutron-rich Na isotopes on the "shore of the island of inversion" by means of neutron-transfer reactions

    CERN Multimedia

    Reiter, P; Blazhev, A A; Riisager, K; Bastin, B; Tengborn, E A; Kruecken, R; Voulot, D; Jeppesen, H B; Hadinia, B; Gernhaeuser, R A; Fynbo, H O U; Georgiev, G P; Habs, D; Fraile prieto, L M; Chapman, R; Nilsson, T; Diriken, J V J; Jenkins, D G; Kroell, T; Leske, J; Huyse, M L; Patronis, N

    We aim at the investigation of single particle properties of neutron-rich Na isotopes around the "shore of the island of inversion". As first experiment of this programme, we propose to study excited states in the isotope $^{29}$Na by a one-neutron transfer reaction with a $^{28}$Na beam at 3 MeV/u obtained from REX-ISOLDE impinging on a CD$_{2}$-target. The $\\gamma$-rays will be detected by the MINIBALL array and the particles by the T-REX array of segmented Si detectors. The main physics aims are to extract from the relative spectroscopic factors information on the configurations contributing to the wave functions of the populated states and, secondly, to identify and characterize negative parity states whose excitation energies reflect directly the N= 28 gap in this region. The results will be compared to recent shell model calculations involving new residual interactions. This will shed new light on the evolution of single particle structure and help to understand the underlying physics relevant for the f...

  3. A conditioning process for ion exchanger resins contaminated with radioactive elements. Procede de conditionnement de resines echangeuses d'ions contaminees par des elements radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Legros, R.; Wiegert, B.; Zeh, J.L.

    1993-08-20

    Ion exchanger resins are embedded in a pre-polymer syrup prepared from acrylic monomers having high boiling point. A curing catalyst (a peroxide) and an activation agent (a tertiary amine) are added. 12 examples are given. 9 p.

  4. Radioactive Material

    CERN Multimedia

    2004-01-01

    The Radiation Protection Group of the Safety Commission is responsible for shipping of radioactive material from CERN to any external institute or organisation. The RP group is equally responsible for the reception of radioactive material shipped to any of the CERN sites. Anyone who needs to ship from or import into CERN radioactive material must contact the Radioactive Shipping Service of the RP group in advance. Instructions are available at: http://cern.ch/rp-shipping or in the Radiation Protection Procedure PRP13: https://edms.cern.ch/document/346823 Radiation Protection Group

  5. Radioactive Material

    CERN Multimedia

    2004-01-01

    The Radiation Protection Group of the Safety Commission is responsible for shipping of radioactive material from CERN to any external institute or organisation. The RP group is equally responsible for the reception of radioactive material shipped to any of the CERN sites. Anyone who needs to ship from or import into CERN radioactive material must contact the Radioactive Shipping Service of the RP group in advance. Instructions are available at: http://cern.ch/rp-shipping or in the Radiation Protection Procedure PRP13: https://edms.cern.ch/document/346823 Radiation Protection Group

  6. Post-acceleration of sup 7 Be at the Louvain-la-Neuve radioactive ion beam facility

    CERN Document Server

    Gaelens, M; Loiselet, M; Ryckewaert, G

    2003-01-01

    The development of an intense and pure post-accelerated sup 7 Be beam at Louvain-la-Neuve will be discussed. Given its properties (metallic nature, long half-life (53 days)) and the special beam parameters required (multi-charge ions, high purity), a range of special techniques had to be investigated. At Louvain-la-Neuve, sup 7 Be is produced by irradiating a lithium target with 30 mu A of 27 MeV protons and is extracted using offline chemical separation techniques. Because of the large amounts of activity required, the chemistry has to be adapted for use in hotcells. The ionization is performed with an Electron Cyclotron Resonance ion source with the sup 7 Be injected in the source by means of sputtering. Special techniques have to be used to prevent the beryllium atoms from being lost on the plasma chamber walls. A dedicated heated plasma chamber for the ion source was developed. The ionization efficiency was increased by studying the chemistry involved in the ion source. The atoms are ionized to the 1+ or ...

  7. Adsorption characteristics of uranyl ions onto micelle surface for treatment of radioactive liquid wastes by micelle enhanced ultrafiltration technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. W.; Choi, W. K.; Jeong, K. H.; Lee, D. K.; Jeong, K. J. [KAERI, Taejon (Korea, Republic of)

    2001-10-01

    The objective of this investigation is to establish the rejection behavior of uranium bearing waste water by micelle enhanced ultrafiltration technique. An extensive experimental investigation was conducted with uranium only and uranium in the presence of electrolyte, utilizing ultrasfiltration stirred cell. The effects of experimental parameters such as solution pH and concentration of uranium on rejection were examined from the change of micelle concentration. The rejection dependence of the uranium was found to be a function of pH and uranium to surfactant concentration ratio. Over 95% removal was observed at pH 3 {approx} 5 and SDS concentration of 40 mM. In the presence of electrolytes, the rejection of uranium was observed to decrease significantly, the addition of cobalt ion showed more reduction than that obtained by presence of sodium and cesium ions on rejection of uranium. The rejection behavior was explained in terms of apparent distribution constants. The rejection efficiencies of uranyl ions was significantly affected by the chemical species of the given system. For all cases, the rejection was highly dependent on uranium complex species.

  8. First-forbidden $\\mathbf{\\beta}$-decay rates, energy rates of $\\beta$-delayed neutrons and probability of $\\beta$-delayed neutron emissions for neutron-rich nickel isotopes

    CERN Document Server

    Nabi, Jameel-Un; Iftikhar, Zafar

    2016-01-01

    First-forbidden (FF) transitions can play an important role in decreasing the calculated half-lives specially in environments where allowed Gamow-Teller (GT) transitions are unfavored. Of special mention is the case of neutron-rich nuclei where, due to phase-space amplification, FF transitions are much favored. We calculate the allowed GT transitions in various pn-QRPA models for even-even neutron-rich isotopes of nickel. Here we also study the effect of deformation on the calculated GT strengths. The FF transitions for even-even neutron-rich isotopes of nickel are calculated assuming the nuclei to be spherical. Later we take into account deformation of nuclei and calculate GT + unique FF transitions, stellar $\\beta$-decay rates, energy rate of $\\beta$-delayed neutrons and probability of $\\beta$-delayed neutron emissions. The calculated half-lives are in excellent agreement with measured ones and might contribute in speeding-up of the $r$-matter flow.

  9. Removal efficiency of radioactive cesium and iodine ions by a flow-type apparatus designed for electrochemically reduced water production.

    Directory of Open Access Journals (Sweden)

    Takeki Hamasaki

    Full Text Available The Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 attracted people's attention, with anxiety over possible radiation hazards. Immediate and long-term concerns are around protection from external and internal exposure by the liberated radionuclides. In particular, residents living in the affected regions are most concerned about ingesting contaminated foodstuffs, including drinking water. Efficient removal of radionuclides from rainwater and drinking water has been reported using several pot-type filtration devices. A currently used flow-type test apparatus is expected to simultaneously provide radionuclide elimination prior to ingestion and protection from internal exposure by accidental ingestion of radionuclides through the use of a micro-carbon carboxymethyl cartridge unit and an electrochemically reduced water production unit, respectively. However, the removability of radionuclides from contaminated tap water has not been tested to date. Thus, the current research was undertaken to assess the capability of the apparatus to remove radionuclides from artificially contaminated tap water. The results presented here demonstrate that the apparatus can reduce radioactivity levels to below the detection limit in applied tap water containing either 300 Bq/kg of 137Cs or 150 Bq/kg of 125I. The apparatus had a removal efficiency of over 90% for all concentration ranges of radio-cesium and -iodine tested. The results showing efficient radionuclide removability, together with previous studies on molecular hydrogen and platinum nanoparticles as reactive oxygen species scavengers, strongly suggest that the test apparatus has the potential to offer maximum safety against radionuclide-contaminated foodstuffs, including drinking water.

  10. ESTIMATION OF RADIOLYTIC GAS GENERATION RATE FOR CYLINDRICAL RADIOACTIVE WASTE PACKAGES - APPLICATION TO SPENT ION EXCHANGE RESIN CONTAINERS

    Energy Technology Data Exchange (ETDEWEB)

    Husain, A.; Lewis, Brent J.

    2003-02-27

    Radioactive waste packages containing water and/or organic substances have the potential to radiolytically generate hydrogen and other combustible gases. Typically, the radiolytic gas generation rate is estimated from the energy deposition rate and the radiolytic gas yield. Estimation of the energy deposition rate must take into account the contributions from all radionuclides. While the contributions from non-gamma emitting radionuclides are relatively easy to estimate, an average geometry factor must be computed to determine the contribution from gamma emitters. Hitherto, no satisfactory method existed for estimating the geometry factors for a cylindrical package. In the present study, a formulation was developed taking into account the effect of photon buildup. A prototype code, called PC-CAGE, was developed to numerically solve the integrals involved. Based on the selected dimensions for a cylinder, the specified waste material, the photon energy of interest and a value for either the absorption or attenuation coefficient, the code outputs values for point and average geometry factors. These can then be used to estimate the internal dose rate to the material in the cylinder and hence to calculate the radiolytic gas generation rate. Besides the ability to estimate the rates of radiolytic gas generation, PC-CAGE can also estimate the dose received by the container material. This is based on values for the point geometry factors at the surface of the cylinder. PC-CAGE was used to calculate geometry factors for a number of cylindrical geometries. Estimates for the absorbed dose rate in container material were also obtained. The results for Ontario Power Generation's 3 m3 resin containers indicate that about 80% of the source gamma energy is deposited internally. In general, the fraction of gamma energy deposited internally depends on the dimensions of the cylinder, the material within it and the photon energy; the fraction deposited increases with increasing

  11. Efficient removal of radioactive iodide ions from water by three-dimensional Ag{sub 2}O–Ag/TiO{sub 2} composites under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shuaishuai; Wang, Na; Zhang, Yuchang; Li, Yaru [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Han, Zhuo [CECEP Environmental Protection Investment Development Co., Ltd., Jiangxi 3300969 (China); Na, Ping, E-mail: naping@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Tianjin Co-Innovation Center of Chemical Science and Engineering, Tianjin 300072 (China)

    2015-03-02

    Highlights: • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites have been synthesized through a facile method. • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites exhibit large photocatalytic adsorption capacity, high selectivity, and excellent trace removal performance of I{sup −} under visible light. • 3D Ag{sub 2}O–Ag/TiO{sub 2} composites could be easily separated and regenerated. • The adsorption capacity of Ag{sub 2}O for I{sup −} is enlarged 4.4 times by the photooxidation of Ag/TiO{sub 2}. • The cooperative effects mechanism between Ag{sub 2}O and Ag/TiO{sub 2} is proposed and verified. - Abstract: Three-dimensional Ag{sub 2}O and Ag co-loaded TiO{sub 2} (3D Ag{sub 2}O–Ag/TiO{sub 2}) composites have been synthesized through a facile method, characterized using SEM, EDX, TEM, XRD, XPS, UV–vis DRS, BET techniques, and applied to remove radioactive iodide ions (I{sup −}). The photocatalytic adsorption capacity (207.6 mg/g) of the 3D Ag{sub 2}O–Ag/TiO{sub 2} spheres under visible light is four times higher than that in the dark, which is barely affected by other ions, even in simulated salt lake water where the concentration of Cl{sup −} is up to 590 times that of I{sup −}. The capability of the composites to remove even trace amounts of I{sup −} from different types of water, e.g., deionized or salt lake water, is demonstrated. The composites also feature good reusability, as they were separated after photocatalytic adsorption and still performed well after a simple regeneration. Furthermore, a mechanism explaining the highly efficient removal of radioactive I{sup −} has been proposed according to characterization analyses of the composites after adsorption and subsequently been verified by adsorption and desorption experiments. The proposed cooperative effects mechanism considers the interplay of three different phenomena, namely, the adsorption performance of Ag{sub 2}O for I{sup −}, the photocatalytic ability of Ag/TiO{sub 2} for oxidation

  12. Ion-implantation and characterization of 32P-radioactive platinum coils for endovascular treatment of intracranial aneurysms

    Science.gov (United States)

    Leblanc, Philippe; Raymond, Jean; Roorda, Sjoerd

    2006-01-01

    We produced and measured over 800 32P-ion-implanted coils for pre-clinical and clinical studies. Platinum coils are intravascular implants most frequently used in the treatment of intracranial aneurysms. This less invasive endovascular approach is safer than conventional surgery, but a frequent drawback is the recurrence of the aneurysm, associated with recanalization, a phenomenon that can be inhibited by the local application of beta radiation. Total coil activities, uniformity, reproducibility and 32P binding to platinum were determined and found to be adequate for this application.

  13. Study of the neutron-rich nuclei with N=21, {sup 35}Si and {sup 33}Mg, by beta decay of {sup 35}Al and {sup 33}Na

    Energy Technology Data Exchange (ETDEWEB)

    Nummela, S. E-mail: saara.nummela@phys.jyu.fi; Baumann, P.; Caurier, E.; Courtin, S.; Dessagne, P.; Holmlund, E.; Jokinen, A.; Knipper, A.; Le Scornet, G.; Mieh, C.; Nowacki, F.; Lyapin, L.G.; Oinonen, M.; Poirier, E.; Radivojevic, Z.; Ramdhane, M.; Trzaska, W.H.; Walter, G.; Aeystoe, J

    2002-04-22

    The first information on the level structure of the N=21 nuclei, {sup 35}Si and {sup 33}Mg, has been obtained by the beta decay study of {sup 35}Al and {sup 33}Na, produced by fragmentation of an UC target with 1.4 GeV protons at CERN/ISOLDE. The experimental technique involved {beta}-{gamma}, {beta}-{gamma}-{gamma}, and {beta}-n-{gamma} coincidences, neutron spectra being obtained by time of flight measurements. Gamma detection was made either using large Ge counters or small BaF{sub 2} scintillators (for lifetime measurements). In the case of the {sup 35}Al decay, (T{sub 1/2}=41.6(2.2) ms), a simple structure has been found for the level scheme of {sup 35}Si (Z=14, N=21) which has been interpreted with the level sequence : 7/2{sup -}, 3/2{sup -} and 3/2{sup +} corresponding respectively to the ground state and the states at 910 and 974 keV. The life-time of the 974 keV [T{sub 1/2}=5.9(6) ns] is found consistent with the proposed level scheme and multipolarities. The investigation of the N=21, very neutron rich isotones, has been carried on with the study of {sup 33}Mg resulting from the {sup 33}Na decay, (T{sub 1/2}=8.0(6) ms). In this case also, a level scheme could be obtained for the first time, with 5 bound states in {sup 32}Mg and {sup 31}Mg levels, populated in the 1n and 2n channels. These results are compared with sd-fp shell model calculations which give a fair account of the Gamow-Teller distribution and a reasonable explanation of the lowest levels with predominant contribution of 1p-1h and 2p-2h excitations.

  14. Simulated Radioactivity

    Science.gov (United States)

    Boettler, James L.

    1972-01-01

    Describes the errors in the sugar-cube experiment related to radioactivity as described in Project Physics course. The discussion considers some of the steps overlooked in the experiment and generalizes the theory beyond the sugar-cube stage. (PS)

  15. Radioactivity Calculations

    Science.gov (United States)

    Onega, Ronald J.

    1969-01-01

    Three problems in radioactive buildup and decay are presented and solved. Matrix algebra is used to solve the second problem. The third problem deals with flux depression and is solved by the use of differential equations. (LC)

  16. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  17. First application of the Trojan Horse Method with a Radioactive Ion Beam: study of the $^{18}$F($p,{\\alpha}$)$^{15}$O}} reaction at astrophysical energies

    CERN Document Server

    Cherubini, S; Spitaleri, C; Rapisarda, G G; La Cognata, M; Lamia, L; Pizzone, R G; Romano, S; Kubono, S; Yamaguchi, H; Hayakawa, S; Wakabayashi, Y; Iwasa, N; Kato, S; Komatsubara, T; Teranishi, T; Coc, A; de Séréville, N; Hammache, F; Kiss, G; Bishop, S; Binh, D N

    2015-01-01

    Measurement of nuclear cross sections at astrophysical energies involving unstable species is one of the most challenging tasks in experimental nuclear physics. The use of indirect methods is often unavoidable in this scenario. In this paper the Trojan Horse Method is applied for the first time to a radioactive ion beam induced reaction studying the $^{18}$F($p,{\\alpha}$)$^{15}$O process at low energies relevant to astrophysics via the three body reaction $^{2}$H($^{18}$F,${\\alpha}^{15}$O)n. The knowledge of the $^{18}$F($p, {\\alpha}$)$^{15}$O reaction rate is crucial to understand the nova explosion phenomena. The cross section of this reaction is characterized by the presence of several resonances in $^{19}$Ne and possibly interference effects among them. The results reported in Literature are not satisfactory and new investigations of the $^{18}$F($p,{\\alpha}$)$^{15}$O reaction cross section will be useful. In the present work the spin-parity assignments of relevant levels have been discussed and the astro...

  18. Design of an equipment for the testing of target dedicated to the production of radioactive ions through the ISOL method; Realisation d'un dispositif de test de cibles pour la production d'ions radioactifs par la methode ISOL

    Energy Technology Data Exchange (ETDEWEB)

    Durantel, F

    2005-01-15

    In the ISOL (isotope separation on line) technique, a primary ion beam impinges on a thick target, the incident ions are stopped through fragmentation reactions that generate radioactive nuclei. As soon as they have collected enough electrons, the radioactive nuclei begin diffusing outside the target as radioactive atoms. In order to improve this diffusion the target is strongly heated. The radioactive atoms diffuse till a ion source that ionize them, they are then accelerated to form a secondary beam that is delivered to the experimental area. This work deals with the design of an equipment able to measure the diffusion capacities of various targets, it is made up of -) a high temperature (> 2300 K) oven that will contain the target, -) a ionization source for ionizing radioactive atoms and -) a target dispatcher able to introduce in the oven or remove from the oven any target of a set of 12 targets. This equipment has proved to be able to test during a single experiment several primary beams and target materials. Measurements will be performed in a sequential way for the different projectile-target couples which will assure very closed experimental conditions for each measuring campaign. (A.C.)

  19. Ion manipulation and precision measurements at JYFLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, A.; Eronen, T.; Hager, U.; Hakala, J.; Kopecky, S.; Rinta-Antila, S.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Nieminen, A. [University of Manchester, Schuster Laboratory, Manchester (United Kingdom)

    2005-09-01

    Various ion manipulation tools based on ion trapping technologies have been implemented at the IGISOL-facility in JYFL. An RFQ ion cooler and buncher is used to enhance the sensitivity of collinear laser spectroscopy and as an injector to the Penning trap. Penning traps are utilized both in nuclear spectroscopy and for precision mass measurements, as explained in the paper. Atomic masses of neutron-rich Zr, Mo and Sr isotopes were found to be in disagreement with the Atomic-Mass Evaluation and two-neutron separation energies imply strong nuclear structure effects at the neutron number N=60. (orig.)

  20. Probing the symmetry energy at high baryon density with heavy ion collisions

    CERN Document Server

    Greco, V; Di Toro, M; Wolter, H H

    2009-01-01

    The nuclear symmetry energy at densities above saturation density ($\\rho_0\\sim 0.16 fm^{-3}$) is poorly constrained theoretically and very few relevant experimental data exist. Its study is possible through Heavy Ion Collisions (HIC) at energies $E/A> 200$ MeV, particularly with beams of neutron-rich radioactive nuclei. The energy range implies that the momentum dependence of the isospin fields, i.e. the difference of the effective masses on protons and neutrons, also has to be investigated before a safe constraint on $\\esy(\\rho)$ is possible. We discuss the several observables which have been suggested, like $n/p$ emission and their collective flows and the ratio of meson yields with different isospin projection, $\\pi^-/\\pi^+$ and $K^0/K^+$. We point out several physical mechanisms that should be included in the theoretical models to allow a direct comparison to the more precise experiments which will be able to distinguish the isospin projection of the detected particles: CSR/Lanzhou, FAIR/GSI, RIBF/RIKEN, ...