Records |
Author |
n_TOF Collaboration (Fujii, K. et al); Domingo-Pardo, C.; Tain, J.L. |
Title |
Neutron physics of the Re/Os clock. III. Resonance analyses and stellar (n, gamma) cross sections of Os-186,Os-187,Os-188 |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
82 |
Issue |
1 |
Pages |
015804 - 18pp |
Keywords |
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Abstract |
Neutron resonance analyses have been performed for the capture cross sections of Os-186, Os-187, and Os-188 measured at the n_TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical analysis to provide a comprehensive experimental basis for modeling of the stellar neutron capture rates of these isotopes in terms of the Hauser-Feshbach statistical model. Consistent calculations for the capture and inelastic reaction channels are crucial for the evaluation of stellar enhancement factors to correct the Maxwellian averaged cross sections obtained from experimental data for the effect of thermally populated excited states. These factors have been calculated for the full temperature range of current scenarios of s-process nucleosynthesis using the combined information of the experimental data in the region of resolved resonances and in the continuum. The consequences of this analysis for the s-process component of the Os-187 abundance and the related impact on the evaluation of the time duration of galactic nucleosynthesis via the Re/Os cosmochronometer are discussed. |
Address |
[Fujii, K.; Abbondanno, U.; Belloni, F.; Milazzo, P. M.; Moreau, C.] Ist Nazl Fis Nucl, I-34149 Trieste, Italy, Email: Kaori.Fujii@ts.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue ![sorted by Series Issue field, descending order (down)](img/sort_desc.gif) |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000279940200009 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
410 |
Permanent link to this record |
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Author |
Cheng, Y.; Csernai, L.P.; Magas, V.K.; Schlei, B.R.; Strottman, D. |
Title |
Matching stages of heavy-ion collision models |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
81 |
Issue |
6 |
Pages |
064910 - 8pp |
Keywords |
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Abstract |
Heavy-ion reactions and other collective dynamical processes are frequently described by different theoretical approaches for the different stages of the process, like initial equilibration stage, intermediate locally equilibrated fluid dynamical stage, and final freeze-out stage. For the last stage, the best known is the Cooper-Frye description used to generate the phase space distribution of emitted, noninteracting particles from a fluid dynamical expansion or explosion, assuming a final ideal gas distribution, or (less frequently) an out-of-equilibrium distribution. In this work we do not want to replace the Cooper-Frye description, but rather clarify the ways of using it and how to choose the parameters of the distribution and, eventually, how to choose the form of the phase space distribution used in the Cooper-Frye formula. Moreover, the Cooper-Frye formula is used in connection with the freeze-out problem, while the discussion of transition between different stages of the collision is applicable to other transitions also. More recently, hadronization and molecular dynamics models have been matched to the end of a fluid dynamical stage to describe hadronization and freeze-out. The stages of the model description can be matched to each other on space-time hypersurfaces (just like through the frequently used freeze-out hypersurface). This work presents a generalized description of how to match the stages of the description of a reaction to each other, extending the methodology used at freeze-out, in simple covariant form which is easily applicable in its simplest version for most applications. |
Address |
[Cheng, Yun; Csernai, L. P.] Univ Bergen, Inst Phys & Technol, N-5007 Bergen, Norway, Email: yun.cheng@uib.no |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Issue ![sorted by Series Issue field, descending order (down)](img/sort_desc.gif) |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000279267600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
417 |
Permanent link to this record |
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Author |
Ljungvall, J. et al; Gadea, A. |
Title |
Onset of collectivity in neutron-rich Fe isotopes: Toward a new island of inversion? |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
81 |
Issue |
6 |
Pages |
061301 - 4pp |
Keywords |
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Abstract |
The lifetimes of the first excited 2(+) states in Fe-62 and Fe-64 have been measured for the first time using the recoil-distance Doppler shift method after multinucleon transfer reactions in inverse kinematics. A sudden increase of collectivity from Fe-62 to Fe-64 is observed. The experimental results are compared with new large-scale shell-model calculations and Hartree-Fock-Bogolyubov-based configuration-mixing calculations using the Gogny D1S interaction. The results give a deeper understanding of the mechanism leading to an onset of collectivity near Ni-68, which is compared with the situation in the so-called island of inversion around Mg-32. |
Address |
[Ljungvall, J.; Goergen, A.; Obertelli, A.; Korten, W.] CEA Saclay, IRFU, Serv Phys Nucl, F-91191 Gif Sur Yvette, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue ![sorted by Series Issue field, descending order (down)](img/sort_desc.gif) |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000278768900001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
424 |
Permanent link to this record |
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Author |
Mukha, I. et al |
Title |
Spectroscopy of proton-unbound nuclei by tracking their decay products in-flight: One- and two-proton decays of F-15, Ne-16, and Na-19 |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
82 |
Issue |
5 |
Pages |
054315 - 14pp |
Keywords |
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Abstract |
A powerful method of investigating proton-unbound nuclear states by tracking their decay products in flight is discussed in detail. To verify the method, four known levels in F-15, Ne-16, and Na-19 were investigated by measuring the angular correlations between protons and the respective heavy-ion fragments stemming from the precursor decays in flight. The parent nuclei of interest were produced in nuclear reactions of one-neutron removal from Ne-17 and Mg-20 projectiles at energies of 410-450 A MeV. The trajectories of the respective decay products, O-14 + p + p and Ne-18 + p + p, were measured by applying a tracking technique with microstrip detectors. These data were used to reconstruct the angular correlations of the fragments, which provided information on energies and widths of the parent states. In addition for reproducing properties of known states, evidence for hitherto unknown excited states in F-15 and Ne-16 was found. This tracking technique has an advantage in studies of exotic nuclei beyond the proton drip line measuring the resonance energies and widths with a high precision although by using low-intensity beams and very thick targets. |
Address |
[Mukha, I.; Suemmerer, K.; Chatillon, A.; Geissel, H.; Grigorenko, L.; Hofmann, J.; Kiselev, O.; Kurz, N.; Litvinov, Yu. A.; Litvinova, E.; Nociforo, C.; Ott, W.; Roeckl, E.; Stanoiu, M.; Weick, H.] GSI Helmholtzzentrum Schwerionenforsch, D-64291 Darmstadt, Germany, Email: I.Mukha@gsi.de |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue ![sorted by Series Issue field, descending order (down)](img/sort_desc.gif) |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000286734500003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
525 |
Permanent link to this record |
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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. |
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 |
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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 |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue ![sorted by Series Issue field, descending order (down)](img/sort_desc.gif) |
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Edition |
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ISSN |
0556-2813 |
ISBN |
|
Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
ISI:000278341300001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
431 |
Permanent link to this record |