Records |
Author |
Wendt, A. et al; Algora, A. |
Title |
Isospin symmetry in the sd shell: Transition strengths in the neutron-deficient sd shell nucleus Ar-33 |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
90 |
Issue |
5 |
Pages |
054301 - 7pp |
Keywords |
|
Abstract |
Reduced transition strengths of the deexciting transitions from the first two excited states in Ar-33 were measured in a relativistic Coulomb excitation experiment at the GSI Helmholtz center. The radioactive ion beam was produced by fragmentation of a primary Ar-36 beam on a Be-9 target followed by the selection of the reaction product of interest via the GSI Fragment Separator. The (33A)r beam hit a secondary Au-197 target with an energy of approximately 145 MeV/nucleon. An array of high-purity germanium cluster detectors and large-volume BaF2 scintillator detectors were employed for gamma-ray spectroscopy at the secondary target position. The Lund-York-Cologne Calorimeter was used to track the outgoing ions and to identify the nuclear reaction channels. For the two lowest energy excited states of Ar-33 the reduced transition strengths have been determined. With these first results the T-z = -3/2 nucleus Ar-33 is now, together with Na-21 (T-z = -1/2), the only neutron-deficient odd-A sd shell nucleus in which experimental transition strengths are available. The experimental values are compared to results of shell-model calculations which describe simultaneously mirror-energy differences and transition-strength values of mirror pairs in the sd shell in a consistent way. |
Address |
[Wendt, A.; Taprogge, J.; Reiter, P.; Blazhev, A.; Braun, N.; Geibel, K.; Hackstein, M.; Moschner, K.; Siebeck, B.; Warr, N.] Univ Cologne, Inst Kernphys, Cologne, Germany |
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 |
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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 |
|
Notes |
WOS:000344489100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2005 |
Permanent link to this record |
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Author |
n_TOF Collaboration (Mendoza, E. et al); Domingo-Pardo, C.; Tain, J.L. |
Title |
Measurement and analysis of the Am-243 neutron capture cross section at the n_TOF facility at CERN |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
90 |
Issue |
3 |
Pages |
034608 - 16pp |
Keywords |
|
Abstract |
Background: The design of new nuclear reactors and transmutation devices requires to reduce the present neutron cross section uncertainties of minor actinides. Purpose: Improvement of the Am-243(n, gamma) cross section uncertainty. Method: The Am-243(n, gamma) cross section has been measured at the n_TOF facility at CERN with a BaF2 total absorption calorimeter, in the energy range between 0.7 eV and 2.5 keV. Results: The Am-243(n, gamma) cross section has been successfully measured in the mentioned energy range. The resolved resonance region has been extended from 250 eV up to 400 eV. In the unresolved resonance region our results are compatible with one of the two incompatible capture data sets available below 2.5 keV. The data available in EXFOR and in the literature have been used to perform a simple analysis above 2.5 keV. Conclusions: The results of this measurement contribute to reduce the Am-243(n, gamma) cross section uncertainty and suggest that this cross section is underestimated up to 25% in the neutron energy range between 50 eV and a few keV in the present evaluated data libraries. |
Address |
[Mendoza, E.; Cano-Ott, D.; Guerrero, C.; Alvarez-Velarde, F.; Balibrea, J.; Gonzalez-Romero, E.; Martinez, T.; Villamarin, D.; Vicente, M. C.] CIEMAT, E-28040 Madrid, Spain |
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 |
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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 |
WOS:000341912100005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1935 |
Permanent link to this record |
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Author |
Gottardo, A. et al; Gadea, A.; Algora, A. |
Title |
Isomeric decay spectroscopy of the Bi-217 isotope |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
90 |
Issue |
3 |
Pages |
034317 - 6pp |
Keywords |
|
Abstract |
The structure of the neutron-rich bismuth isotope Bi-217 has been studied for the first time. The fragmentation of a primary U-238 beam at the FRS-RISING setup at GSI was exploited to perform gamma-decay spectroscopy, since μs isomeric states were expected in this nucleus. Gamma rays following the decay of a t(1/2) = 3 μs isomer were observed, allowing one to establish the low-lying structure of Bi-217. The level energies and the reduced electric quadrupole transition probability B(E2) from the isomeric state are compared to large-scale shell-model calculations. |
Address |
[Gottardo, A.; Valiente-Dobon, J. J.; de Angelis, G.; Modamio, V.; Napoli, D. R.; Sahin, E.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: andrea.gottardo@lnl.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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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 |
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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 |
|
Notes |
WOS:000342140100003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1930 |
Permanent link to this record |
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Author |
AGATA Collaboration (John, P.R. et al); Gadea, A. |
Title |
Shape evolution in the neutron-rich osmium isotopes: Prompt gamma-ray spectroscopy of Os-196 |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
90 |
Issue |
2 |
Pages |
021301 - 6pp |
Keywords |
|
Abstract |
The shape transition in the neutron-rich Os isotopes is studied by investigating the neutron-rich Os-196 nucleus through in-beam gamma-ray spectroscopy using a two-proton transfer reaction from a Pt-198 target to a Se-82 beam. The beam-like recoils were detected and identified with the large-acceptance magnetic spectrometer PRISMA, and the coincident gamma rays were measured with the advanced gamma tracking array (AGATA) demonstrator. The de-excitation of the low-lying levels of the yrast-band of Os-196 were identified for the first time. The results are compared with state-of-the-art beyond-mean-field calculations, performed for the even-even Os188-198 isotopes. The new results suggest a smooth transition in the Os isotopes from a more axial rotational behavior towards predominately vibrational nuclei through triaxial configurations. An almost perfect gamma-unstable/triaxial rotor yrast band is predicted for Os-196 which is in agreement with the experimentally measured excited states. |
Address |
[John, P. R.; Mengoni, D.; Lunardi, S.; Gottardo, A.; Lenzi, S.; Menegazzo, R.; Michelagnoli, C.; Molini, P.; Montagnoli, G.; Montanari, D.; Recchia, F.; Scarlassara, F.] Univ Padua, Dipartimento Fis & Astron, I-35131 Padua, Italy, Email: philipp.john@pd.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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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 |
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Edition |
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ISSN |
0556-2813 |
ISBN |
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Medium |
|
Area |
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Expedition |
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Conference |
|
Notes |
WOS:000341105200001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1909 |
Permanent link to this record |
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Author |
Karakoc, M. et al; Molina, F. |
Title |
Gamow-Teller transitions in the A=40 isoquintet of relevance for neutrino captures in Ar-40 |
Type |
Journal Article |
Year |
2014 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
89 |
Issue |
6 |
Pages |
064313 - 7pp |
Keywords |
|
Abstract |
Background: The Gamow-Teller response of Ar-40 is important for the use of liquid argon as a medium for neutrino detection. An ambiguity about the Gamow-Teller strength for the excitation of 1(+) states at 2290 and 2730 keV in K-40 results in a significant uncertainty for neutrino capture rates. This ambiguity is caused by the large discrepancy observed between strengths extracted from Ar-40(p, n) charge-exchange data and the transition strengths for the analog transitions studied in the beta decay of Ti-40. Purpose: This study was aimed at resolving the ambiguity between the results from the Ar-40(p, n) charge-exchange and Ti-40 beta-decay data. Method: Shell-model calculations in the sd-pf shell with a new interaction (WBMB-C) were used to study differences between the structure of the transitions from Ar-40 and Ti-40. Distorted-wave Born approximation reaction calculations were used to investigate uncertainties in the extraction of Gamow-Teller strength from the Ar-40(p, n) data. New high-resolution data for the Ar-40(He-3,t) reaction were used to gain further insight into the charge-exchange reaction mechanism and to provide more information to test the validity of the shell-model calculations. Results: The shell-model calculations showed that interference between amplitudes associated with pf and sd components to the low-lying Gamow-Teller transitions, in combination with a difference in Coulomb energy shifts for Ar-40 and Ti-40, can produce the differences on the scale of those observed between the Ar-40 charge-exchange and Ti-40 beta-decay data. In combination with the difference in nuclear penetrability of the (p, n) and (He-3,t) probes, the different contributions from amplitudes associated with transitions in the pf and sd shells are likely also responsible for the observed discrepancy between the ratio of the cross sections for the low-lying 1(+) states in the Ar-40(p, n) and Ar-40(He-3,t) data. Conclusions: On the basis of this study, it is recommended to use Gamow-Teller strengths extracted from the Ar-40(p, n) data, not the Ti-40 beta-decay data, for the calculation of neutrino capture rates. Further theoretical studies are required to achieve a consistent quantitative description for the energy differences between low-lying 1(+) states in K-40 and Sc-40 and the experimentally observed Gamow-Teller strengths. |
Address |
[Karakoc, M.; Boztosun, I.] Akdeniz Univ, Dept Phys, TR-07058 Antalya, Turkey, Email: zegers@nscl.msu.edu |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
|
Editor |
|
Language |
English |
Summary Language |
|
Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0556-2813 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000338641500002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1851 |
Permanent link to this record |