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Author Mengoni, D. et al; Gadea, A.; Algora, A.; Rubio, B. doi  openurl
  Title Lifetime measurements of excited states in neutron-rich Ar-44,Ar-46 populated via a multinucleon transfer reaction Type Journal Article
  Year 2010 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 82 Issue 2 Pages 024308 - 7pp  
  Keywords  
  Abstract Lifetimes of low-lying excited states of the neutron-rich Ar-44,Ar-46 nuclei, populated via multinucleon transfer reactions, are measured by means of the differential recoil distance Doppler shift method. The extracted electromagnetic transition probabilities are compared with previous intermediate-energy Coulomb-excitation measurements and with large-scale shell-model calculations. The increase in the deduced B( E2; 2(+) -> 0(+)) transition probability from Ar-44 to the closed-shell nucleus Ar-46 contradicts the earlier results of Coulomb-excitation experiments. Shell-model calculations using different effective interactions agree with the new measured values.  
  Address [Mengoni, D.; Angus, L. J.; Orlandi, R.; Smith, J. F.; Wady, P. T.] Univ W Scotland, Sch Engn, Paisley PA1 2BE, Renfrew, Scotland, Email: mengoni@pd.infn.it  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000280759100002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 394  
Permanent link to this record
 

 
Author Algora, A. et al; Jordan, D.; Tain, J.L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A.B.; Molina, F.; Caballero, L.; Nacher, E. doi  openurl
  Title Reactor Decay Heat in Pu-239: Solving the gamma Discrepancy in the 4-3000-s Cooling Period Type Journal Article
  Year 2010 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 105 Issue 20 Pages 202501 - 4pp  
  Keywords  
  Abstract The beta feeding probability of Tc-102,Tc- 104,Tc- 105,Tc- 106,Tc- 107, Mo-105, and Nb-101 nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a long-standing discrepancy in the gamma component of the decay heat for Pu-239 in the 4-3000 s range.  
  Address [Algora, A.; Jordan, D.; Tain, J. L.; Rubio, B.; Agramunt, J.; Perez-Cerdan, A. B.; Molina, F.; Caballero, L.; Nacher, E.] Univ Valencia, IFIC, CSIC, Valencia, Spain, Email: algora@ific.uv.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000283927700004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 328  
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Author Rodriguez, D. et al; Algora, A.; Rubio, B.; Tain, J.L. doi  openurl
  Title MATS and LaSpec: High-precision experiments using ion traps and lasers at FAIR Type Journal Article
  Year 2010 Publication European Physical Journal-Special Topics Abbreviated Journal Eur. Phys. J.-Spec. Top.  
  Volume 183 Issue Pages 1-123  
  Keywords  
  Abstract Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique “fingerprint”. Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10(-5) to below 10(-8) for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10(-9) can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. This accuracy limit is important for fundamental interaction tests, but also allows for the study of the fine structure of the nuclear mass surface with unprecedented accuracy, whenever required. The use of the FT-ICR technique provides true single ion sensitivity. This is essential to access isotopes that are produced with minimum rates which are very often the most interesting ones. Instead of pushing for highest accuracy, the high charge state of the ions can also be used to reduce the storage time of the ions, hence making measurements on even shorter-lived isotopes possible. Decay studies in ion traps will become possible with MATS. Novel spectroscopic tools for in-trap high-resolution conversion-electron and charged-particle spectroscopy from carrier-free sources will be developed, aiming e. g. at the measurements of quadrupole moments and E0 strengths. With the possibility of both high-accuracy mass measurements of the shortest-lived isotopes and decay studies, the high sensitivity and accuracy potential of MATS is ideally suited for the study of very exotic nuclides that will only be produced at the FAIR facility. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The dependencies of the hyperfine splitting and isotope shift on the nuclear moments and mean square nuclear charge radii are well known and the theoretical framework for the extraction of nuclear parameters is well established. These extracted parameters provide fundamental information on the structure of nuclei at the limits of stability. Vital information on both bulk and valence nuclear properties are derived and an exceptional sensitivity to changes in nuclear deformation is achieved. Laser spectroscopy provides the only mechanism for such studies in exotic systems and uniquely facilitates these studies in a model-independent manner. The accuracy of laser-spectroscopic-determined nuclear properties is very high. Requirements concerning production rates are moderate; collinear spectroscopy has been performed with production rates as few as 100 ions per second and laser-desorption resonance ionization mass spectroscopy (combined with beta-delayed neutron detection) has been achieved with rates of only a few atoms per second. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy, which will provide a complete system with respect to the physics and isotopes that can be studied. Since MATS and LaSpec require high-quality low-energy beams, the two collaborations have a common beamline to stop the radioactive beam of in-flight produced isotopes and prepare them in a suitable way for transfer to the MATS and LaSpec setups, respectively.  
  Address [Rodriguez, D.; Lallena, A. M.] Univ Granada, Dept Fis Atom Mol & Nucl, E-18071 Granada, Spain, Email: danielrodriguez@ugr.es  
  Corporate Author Thesis  
  Publisher Springer Heidelberg Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1951-6355 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000280061400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 412  
Permanent link to this record
 

 
Author Deo, A.Y.; Podolyak, Z.; Walker, P.M.; Algora, A.; Rubio, B.; Agramunt, J.; Fraile, L.M.; Al-Dahan, N.; Alkhomashi, N.; Briz, J.A.; Estevez, E.; Farrelly, G.; Gelletly, W.; Herlert, A.; Koster, U.; Maira, A.; Singla, S. doi  openurl
  Title Structures of Po-201 and Rn-205 from EC/beta(+)-decay studies Type Journal Article
  Year 2010 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 81 Issue 2 Pages 024322 - 8pp  
  Keywords  
  Abstract Several low-lying excited states in Rn-205(86)119 and Po-201(84)117 were identified for the first time following EC/beta(+) decay of Fr-205 and At-201, respectively, using gamma-ray and conversion electron spectroscopy at the CERN isotope separator on-line (ISOLDE) facility. The EC/beta(+) branch from Fr-205 was measured to be 1.5(2)%. The excited states of the daughter nuclei are understood in terms of the odd nucleon coupling to the neighboring even-even core. The neutron single-particle energies of the p(3/2) orbital relative to the f(5/2) ground state in Rn-205, and the f(5/2) orbital relative to the p(3/2) ground state in Po-201, were determined to be 31.4(2) and 5.7(3) keV, respectively. We tentatively identify a 13/2(+) isomeric level at 657.1(5) keV in Rn-205. The systematic behavior of the 13/2(+) and 3/2(-) levels is also discussed.  
  Address [Deo, A. Y.; Podolyak, Zs.; Walker, P. M.; Al-Dahan, N.; Alkhomashi, N.; Farrelly, G.; Gelletly, W.] Univ Surrey, Dept Phys, Guildford GU2 7XH, Surrey, England, Email: A.Deo@surrey.ac.uk  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000278341300001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 431  
Permanent link to this record
 

 
Author Modamio, V.; Jungclaus, A.; Algora, A.; Bazzacco, D.; Escrig, D.; Fraile, L.M.; Lenzi, S.; Marginean, N.; Martinez, T.; Napoli, D.R.; Schwengner, R.; Ur, C.A. doi  openurl
  Title New high-spin isomer and quasiparticle-vibration coupling in Ir-187 Type Journal Article
  Year 2010 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 81 Issue 5 Pages 054304 - 13pp  
  Keywords  
  Abstract The high-spin structure of the Z = 77 nucleus Ir-187 has been studied using the fusion-evaporation reaction W-186(Li-7, (6)n) at a beam energy of 59 MeV. The excitation scheme of this nucleus has been extended by more than 110 new states, including extensions of all previously established rotational bands. The band crossing region of the h(9/2) negative-parity yrast band has been revised and new intrinsic high-K states have been identified. In particular, a 29/2(-) isomeric state [T-1/2 = 1.8(5)mu s] at an excitation energy of 2487 keV has been observed for the first time, and on top of it, a rich level scheme reaching up to spin (59/2(-)) and excitation energies around 7 MeV has been established.  
  Address [Modamio, V.; Jungclaus, A.; Escrig, D.] CSIC, Inst Estruct Mat, E-28006 Madrid, Spain, Email: andrea.jungclaus@iem.cfmac.csic.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000278144800015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 441  
Permanent link to this record
 

 
Author Caballero, L.; Rubio, B.; Kleinheinz, P.; Yates, S.W.; Algora, A.; Dewald, A.; Fitzler, A.; Gadea, A.; Jolie, J.; Julin, R.; Linnemann, A.; Lunardi, S.; Menegazzo, R.; Moller, O.; Nacher, E.; Piiparinen, M.; Blomqvist, J. doi  openurl
  Title Two-phonon octupole excitation in Gd-146 Type Journal Article
  Year 2010 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 81 Issue 3 Pages 031301 - 4pp  
  Keywords  
  Abstract Based on experimental evidence from the Sm-144(alpha,2n) reaction, the 3484.7- keV 6(+) state in Gd-146 is identified as the highest-spin member of the 3(-) circle times 3(-) two-phonon octupole quartet. A previously unknown gamma line of 1905.8 keV and E3 character feeding the 3(-) octupole state has been observed. These results represent the first observation of a 6(+) -> 3(-) -> 0(+) cascade of two E3 transitions in an even-even nucleus and provide strong support for the interpretation of the 6(+) state as a two-phonon octupole excitation.  
  Address [Caballero, L.; Rubio, B.; Algora, A.; Gadea, A.; Nacher, E.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: Berta.Rubio@ific.uv.es  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000276769400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 468  
Permanent link to this record
 

 
Author Soderstrom, P.A. et al; Algora, A.; Gadea, A. url  doi
openurl 
  Title Spectroscopy of neutron-rich Dy-168,Dy-170: Yrast band evolution close to the NpNn valence maximum Type Journal Article
  Year 2010 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 81 Issue 3 Pages 034310 - 5pp  
  Keywords  
  Abstract The yrast sequence of the neutron-rich dysprosium isotope Dy-168 has been studied using multinucleon transfer reactions following collisions between a 460-MeV Se-82 beam and an 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 have been confirmed and the yrast band extended up to 10(+). A tentative candidate for the 4(+) -> 2(+) transition in Dy-170 was also identified. The data on these nuclei and on the lighter even-even dysprosium isotopes are interpreted in terms of total Routhian surface calculations and the evolution of collectivity in the vicinity of the proton-neutron valence product maximum is discussed.  
  Address [Soderstrom, P. -A.; Nyberg, J.] Uppsala Univ, Dept Phys & Astron, SE-75121 Uppsala, Sweden  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000276769400026 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 469  
Permanent link to this record
 

 
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 (up) 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 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 (up) 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 IFIC @ pastor @ Serial 649  
Permanent link to this record
 

 
Author Darai, J.; Cseh, J.; Antonenko, N.V.; Royer, G.; Algora, A.; Hess, P.O.; Jolos, R.V.; Scheid, W. doi  openurl
  Title Clusterization in the shape isomers of the (56)Ni nucleus Type Journal Article
  Year 2011 Publication Physical Review C Abbreviated Journal  
  Volume 84 Issue 2 Pages 024302  
  Keywords  
  Abstract The interrelation of the quadrupole deformation and clusterization is investigated in the example of the (56)Ni nucleus. The shape isomers, including superdeformed and hyperdeformed states, are obtained as stability regions of the quasidynamical U(3) symmetry based on a Nilsson calculation. Their possible binary clusterizations are investigated by considering both the consequences of the Pauli exclusion principle and the energetic preference.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title (up) Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0556-2813 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000293619100002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 714  
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