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Author Cederwall, B. et al; Algora, A.; Gadea, A. url  doi
openurl 
  Title Evidence for a spin-aligned neutron-proton paired phase from the level structure of Pd-92 Type Journal Article
  Year 2011 Publication Nature Abbreviated Journal Nature  
  Volume 469 Issue 7328 Pages 68-71  
  Keywords  
  Abstract Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.  
  Address [Cederwall, B.; Moradi, F. Ghazi; Back, T.; Johnson, A.; Blomqvist, J.; Andgren, K.; Lagergren, K.; Liotta, R.; Qi, C.; Hadinia, B.; Khaplanov, A.; Persson, A.; Sandzelius, M.] Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden, Email: cederwall@nuclear.kth.se  
  Corporate Author Thesis  
  Publisher Nature Publishing Group Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028-0836 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000285921600032 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 588  
Permanent link to this record
 

 
Author Guess, C.J. et al; Algora, A.; Estevez, E.; Molina, F.; Rubio, B. url  doi
openurl 
  Title The Nd-150(He-3,t) and Sm-150(t,He-3) reactions with applications to beta beta decay of Nd-150 Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 83 Issue 6 Pages 064318 - 17pp  
  Keywords  
  Abstract The Nd-150(3He,t) reaction at 140 MeV/u and Sm-150(t,He-3) reaction at 115 MeV/u were measured, populating excited states in Pm-150. The transitions studied populate intermediate states of importance for the (neutrinoless) beta beta decay of Nd-150 to Sm-150. Monopole and dipole contributions to the measured excitation-energy spectra were extracted by using multipole decomposition analyses. The experimental results were compared with theoretical calculations obtained within the framework of the quasiparticle random-phase approximation, which is one of the main methods employed for estimating the half-life of the neutrinoless beta beta decay (0 nu beta beta) of Nd-150. The present results thus provide useful information on the neutrino responses for evaluating the 0 nu beta beta and 2 nu beta beta matrix elements. The 2 nu beta beta matrix element calculated from the Gamow-Teller transitions through the lowest 1(+) state in the intermediate nucleus is maximally about half that deduced from the half-life measured in 2 nu beta beta direct counting experiments, and at least several transitions through 1+ intermediate states in Pm-150 are required to explain the 2 nu beta beta half-life. Because Gamow-Teller transitions in the Sm-150(t,3He) experiment are strongly Pauli blocked, the extraction of Gamow-Teller strengths was complicated by the excitation of the 2 (h) over bar omega, Lambda L = 0, Delta S = 1 isovector spin-flip giant monopole resonance (IVSGMR). However, the near absence of Gamow-Teller transition strength made it possible to cleanly identify this resonance, and the strength observed is consistent with the full exhaustion of the non-energy-weighted sum rule for the IVSGMR.  
  Address [Guess, C. J.; Austin, Sam M.; Bazin, D.; Brown, B. A.; Caesar, C.; Deaven, J. M.; Grinyer, G. F.; Herlitzius, C.; Hitt, G. W.; Meharchand, R.; Perdikakis, G.; Verhanovitz, N.; Yurkon, J.; Zegers, R. G. T.] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA, Email: carol.guess@gmail.com  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000291729400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 649  
Permanent link to this record
 

 
Author Morales, A.I. et al; Agramunt, J.; Algora, A.; Gadea, A.; Molina, F.; Rubio, B. doi  openurl
  Title Synthesis of N=127 isotones through (p,n) charge-exchange reactions induced by relativistic (208)Pb projectiles Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 84 Issue 1 Pages 011601 - 5pp  
  Keywords  
  Abstract The production cross sections of four N = 127 isotones ((207)Hg, (206)Au, (205)Pt, and (204)Ir) have been measured using (p,n) charge-exchange reactions, induced in collisions of a (208)Pb primary beam at 1 A GeV with a Be target. These data allow one to investigate the use of a reaction mechanism to extend the limits of the chart of nuclides toward the important r-process nuclei in the region of the third peak of elemental abundance distribution.  
  Address [Morales, AI; Benlliure, J; Alvarez-Pol, H; Casarejos, E; Dragosavac, D; Perez-Loureiro, D; Verma, S] Univ Santiago de Compostela, Santiago De Compostela 15782, Spain, Email: anaisabel.morales@usc.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000292925800001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 697  
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Author Langer, C.; Algora, A.; Couture, A.; Csatlos, M.; Gulyas, J.; Heil, M.; Krasznahorkay, A.; O'Donnell, J.M.; Plag, R.; Reifarth, R.; Stuhl, L.; Sonnabend, K.; Tornyi, T.; Tovesson, F. doi  openurl
  Title Simulations and developments of the Low Energy Neutron detector Array LENA Type Journal Article
  Year 2011 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 659 Issue 1 Pages 411-418  
  Keywords Monte Carlo simulations; Charge-exchange reactions; Scintillation detectors; Neutron detector  
  Abstract Prototypes of the Low Energy Neutron detector Array (LENA) have been tested and compared with detailed GEANT simulations. LENA will consist of plastic scintillation bars with the dimensions 1000 x 45 x 10 mm(3). The tests have been performed with gamma-ray sources and neutrons originating from the neutron-induced fission of (235)U. The simulations agreed very well with the measured response and were therefore used to simulate the response to mono-energetic neutrons with different detection thresholds. LENA will be used to detect low-energy neutrons from (p,n)-type reactions with low momentum transfer foreseen at the R(3)B and EXL setups at FAIR, Darmstadt.  
  Address [Langer, C.; Heil, M.; Plag, R.; Reifarth, R.] GSI Helmholtzzentrum Schwerionenforsch GmbH, D-64291 Darmstadt, Germany, Email: c.langer@gsi.de  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000297826100057 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 833  
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Author AGATA Collaboration (Akkoyun, S. et al); Algora, A.; Barrientos, D.; Domingo-Pardo, C.; Egea, F.J.; Gadea, A.; Huyuk, T.; Kaci, M.; Mendez, V.; Rubio, B.; Salt, J.; Tain, J.L. url  doi
openurl 
  Title AGATA-Advanced GAmma Tracking Array Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 668 Issue Pages 26-58  
  Keywords AGATA; gamma-Ray spectroscopy; gamma-Ray tracking; HPGe detectors; Digital signal processing; Pulse-shape and gamma-ray tracking algorithms; Semiconductor detector performance and simulations  
  Abstract The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realisation of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterisation of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximise its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.  
  Address [Boston, A. J.; Boston, H. C.; Colosimo, S.; Cooper, R. J.; Cresswell, J. R.; Dimmock, M. R.; Filmer, F.; Grint, A. N.; Harkness, L. J.; Judson, D. S.; Mather, A. R.; Moon, S.; Nelson, L.; Nolan, P. J.; Norman, M.; Oxley, D. C.; Rigby, S.; Sampson, J.; Scraggs, D. P.; Seddon, D.; Slee, M.; Stanios, T.; Thornhill, J.; Unsworth, C.; Wells, D.] Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England, Email: a.j.boston@liverpool.ac.uk  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000300864200005 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 923  
Permanent link to this record
 

 
Author Al-Dahan, N. et al; Algora, A.; Molina, F.; Rubio, B. doi  openurl
  Title Multiple beta(-) decaying states in Re-194: Shape evolution in neutron-rich osmium isotopes Type Journal Article
  Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 85 Issue 3 Pages 034301 - 9pp  
  Keywords  
  Abstract beta decays from heavy, neutron-rich nuclei with A similar to 190 have been investigated following their production via the relativistic projectile fragmentation of an E/A = 1 GeV Pb-208 primary beam on a similar to 2.5 g/cm(2) Be-9 target. The reaction products were separated and identified using the GSI FRagment Separator (FRS) and stopped in the RISING active stopper. gamma decays were observed and correlated with these secondary ions on an event-by-event basis such that gamma-ray transitions following from both internal (isomeric) and beta decays were recorded. A number of discrete, beta-delayed gamma-ray transitions associated with beta decays from Re-194 to excited states in Os-194 have been observed, including previously reported decays from the yrast I-pi = (6(+)) state. Three previously unreported gamma-ray transitions with energies 194, 349, and 554 keV are also identified; these transitions are associated with decays from higher spin states in Os-194. The results of these investigations are compared with theoretical predictions from Nilsson multi-quasiparticle (MQP) calculations. Based on lifetime measurements and the observed feeding pattern to states in Os-194, it is concluded that there are three beta(-)-decaying states in Re-194.  
  Address [Al-Dahan, N.] Univ Kerbala, Coll Sci, Dept Phys, Kerbala, Iraq, Email: p.regan@surrey.ac.uk  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000301113800002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 932  
Permanent link to this record
 

 
Author Sohler, D. et al; Algora, A. doi  openurl
  Title High-spin structure of Pd-104 Type Journal Article
  Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 85 Issue 4 Pages 044303 - 13pp  
  Keywords  
  Abstract The high-spin structure of the nucleus Pd-104 was studied through the Zr-96(C-13,5n) reaction at incident energies of 51 and 58MeV, using the Euroball IV gamma-ray spectrometer in conjunction with the DIAMANT charged-particle array. Several new medium- and high-spin bands were revealed. The already known positive-parity yrast and the negative-parity cascades were extended up to E-x similar to 13, similar to 11, and similar to 9 MeV with I-pi = (26(+)), I-pi = (23(-)), and (20(-)), respectively. The deduced band structures were compared with Woods-Saxon total Routhian surface (TRS) calculations. In addition, non-yrast low-lying positive-parity bands were identified, which were assigned to soft gamma-vibrational excitations.  
  Address [Sohler, D.; Kuti, I.; Timar, J.; Molnar, J.; Algora, A.; Dombradi, Zs; Gal, J.; Kalinka, G.; Krasznahorkay, A.; Nyako, B. M.; Zolnai, L.] Inst Nucl Res, H-4001 Debrecen, Hungary  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000302237400004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 972  
Permanent link to this record
 

 
Author Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Tain, J.L.; Algora, A.; Berthoumieux, E.; Colonna, N.; Domingo-Pardo, C.; Gonzalez-Romero, E.; Heil, M.; Jordan, D.; Kappeler, F.; Lampoudis, C.; Martinez, T.; Massimi, C.; Plag, R. doi  openurl
  Title Monte Carlo simulation of the n_TOF Total Absorption Calorimeter Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 671 Issue Pages 108-117  
  Keywords Monte Carlo simulation; Geant4; Neutron cross-sections; Time-of-flight; Neutron capture  
  Abstract The n_TOF Total Absorption Calorimeter (TAC) is a 4 pi BaF2 segmented detector used at CERN for measuring neutron capture cross-sections of importance for the design of advanced nuclear reactors. This work presents the simulation code that has been developed in GEANT4 for the accurate determination of the detection efficiency of the TAC for neutron capture events. The code allows to calculate the efficiency of the TAC for every neutron capture state, as a function of energy, crystal multiplicity, and counting rate. The code includes all instrumental effects such as the single crystal detection threshold and energy resolution, finite size of the coincidence time window, and signal pile-up. The results from the simulation have been validated with experimental data for a large set of electromagnetic de-excitation patterns: beta-decay of well known calibration sources, neutron capture reactions in light nuclei with well known level schemes like Ti-nat, reference samples used in (n,gamma) measurements like Au-197 and experimental data from an actinide sample like Pu-240. The systematic uncertainty in the determination of the detection efficiency has been estimated for all the cases. As a representative example, the accuracy reached for the case of Au-197(n,gamma) ranges between 0.5% and 2%, depending on the experimental and analysis conditions. Such a value matches the high accuracy required for the nuclear cross-section data needed in advanced reactor design.  
  Address [Guerrero, C.; Cano-Ott, D.; Mendoza, E.; Gonzalez-Romero, E.; Martinez, T.] CIEMAT, Ctr Invest Energet Medioambientales & Tecnol, E-28040 Madrid, Spain, Email: carlos.guerrero@cern.ch  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000301474600013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 973  
Permanent link to this record
 

 
Author Garcia, A.R.; Martinez, T.; Cano-Ott, D.; Castilla, J.; Guerrero, C.; Marin, J.; Martinez, G.; Mendoza, E.; Ovejero, M.C.; Reillo, E.M.; Santos, C.; Tera, F.J.; Villamarin, D.; Nolte, R.; Agramunt, J.; Algora, A.; Tain, J.L.; Banerjee, K.; Bhattacharya, C.; Pentilla, H.; Rinta-Antila, S.; Gorelov, D. doi  openurl
  Title MONSTER: a time of flight spectrometer for beta-delayed neutron emission measurements Type Journal Article
  Year 2012 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 7 Issue Pages C05012 - 12pp  
  Keywords Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators); Instrumentation and methods for time-of-flight (TOF) spectroscopy; Neutron detectors (cold, thermal, fast neutrons)  
  Abstract The knowledge of the beta-decay properties of nuclei contributes decisively to our understanding of nuclear phenomena: the beta-delayed neutron emission of neutron rich nuclei plays an important role in the nucleosynthesis r-process and constitutes a probe for nuclear structure of very neutron rich nuclei providing information about the high energy part of the full beta strength (S-beta) function. In addition, beta-delayed neutrons are essential for the control and safety of nuclear reactors. In order to determine the neutron energy spectra and emission probabilities from neutron precursors a MOdular Neutron time-of-flight SpectromeTER (MONSTER) has been proposed for the DESPEC experiment at the future FAIR facility. The design of MONSTER and status of its construction are reported in this work.  
  Address [Garcia, A. R.; Martinez, T.; Cano-Ott, D.; Castilla, J.; Guerrero, C.; Marin, J.; Martinez, G.; Mendoza, E.; Ovejero, M. C.; Reillo, E. M.; Santos, C.; Tera, F. J.; Villamarin, D.] Ctr Invest Energet MedioAmbientales & Tecnol CIEM, E-28040 Madrid, Spain, Email: trino.martinez@ciemat.es  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000305419700013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1084  
Permanent link to this record
 

 
Author Kowalska, M.; Naimi, S.; Agramunt, J.; Algora, A.; Beck, D.; Blank, B.; Blaum, K.; Bohm, C.; Borgmann, C.; Breitenfeldt, M.; Fraile, L.M.; George, S.; Herfurth, F.; Herlert, A.; Kreim, S.; Lunney, D.; Minaya-Ramirez, E.; Neidherr, D.; Rosenbusch, M.; Rubio, B.; Schweikhard, L.; Stanja, J.; Zuber, K. doi  openurl
  Title Trap-assisted decay spectroscopy with ISOLTRAP Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 689 Issue Pages 102-107  
  Keywords Penning trap mass spectrometers; Trap-assisted decay spectroscopy; Studies at ISOL-type facilities  
  Abstract Penning traps are excellent high-precision mass spectrometers for radionuclides. The high-resolving power used for cleaning isobaric and even isomeric contaminants can be exploited to improve decay-spectroscopy studies by delivering purified samples. An apparatus allowing trap-assisted decay spectroscopy has been coupled to the ISOLTRAP mass spectrometer at ISOLDE/CERN. The results from studies with stable and radioactive ions show that the setup can be used to perform decay studies on purified short-lived nuclides and to assist mass measurements.  
  Address [Kowalska, M.; Herlert, A.] CERN, Dept Phys, CH-1211 Geneva 23, Switzerland, Email: kowalska@cern.ch  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000307797500016 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number (down) IFIC @ pastor @ Serial 1134  
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