1. |
- Stefanescu, I, et al.
(författare)
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Interplay between single-particle and collective effects in the odd-A Cu isotopes beyond N=40
- 2008
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Ingår i: Physical Review Letters. - 1079-7114. ; 100:11
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Tidskriftsartikel (refereegranskat)abstract
- Collective properties of the low-lying levels in the odd-A Cu67-73 were investigated by Coulomb excitation with radioactive beams. The beams were produced at ISOLDE and postaccelerated by REX-ISOLDE up to 2.99 MeV/u. In Cu-67,Cu-69, low-lying 1/2(-), 5/2(-), and 7/2(-) states were populated. In Cu-71,Cu-73, besides the known transitions deexciting the single-particle-like 5/2(-) and core-coupled 7/2(-) levels, gamma rays of 454 and 135 keV, respectively, were observed for the first time. Based on a reanalysis of beta-decay work and comparison with the systematics, a spin 1/2(-) is suggested for these excited states. Three B(E2) values were determined in each of the four isotopes. The results indicate a significant change in the structure of the odd-A Cu isotopes beyond N=40 where single-particle-like and collective levels are suggested to coexist at very low excitation energies.
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2. |
- Kröll, T., et al.
(författare)
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Transfer Reactions on Neutron-rich Nuclei at REX-ISOLDE
- 2009
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Ingår i: AIP Conference Proceedings. - 1551-7616 .- 0094-243X. ; 1165, s. 363-368 461
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Konferensbidrag (refereegranskat)abstract
- We report on one- and two-neutron transfer reactions to study the single-particle properties of nuclei at the border of the "island of inversion". The (d,p)- and (t,p)-reactions in inverse kinematics on the neutron-rich isotope Mg-30, delivered as radioactive beam by the REX-ISOLDE facility, have been investigated. The outgoing protons have been detected and identified by a newly built array of Si detectors. The gamma-decay of excited states has been detected in coincidence by the MINIBALL array. First results for Mg-31 and from the search for the second, spherical, 0(+) state in Mg-32 are presented.
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3. |
- Van de Walle, J., et al.
(författare)
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In-trap decay of Mn-61 and Coulomb excitation of Mn-61/Fe-61
- 2009
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 42:3, s. 401-406
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Konferensbidrag (refereegranskat)abstract
- At ISOL ( Isotope Separator On-Line) facilities, which utilize thick primary production targets, beams of neutron-rich iron isotopes are dificult to obtain due to the long extraction time of these isotopes out of the target matrix. At REX-ISOLDE, an exploratory experiment was carried out to investigate the possibility of producing a post-accelerated beam of neutron-rich iron isotopes by the in-trap decay of neutron-rich manganese isotopes, which are available at ISOLDE using the Resonance Ionization Laser Ion Source (RILIS). This production mechanism was tested for the first time at REX-ISOLDE with an intense and short-lived beam of Mn-61 isotopes. In this work, the proof of principle of this method is demonstrated, although the technical details of the trapping process are currently not well understood and are still under investigation. The first physics results on the Coulomb excitation of Mn-61 and Fe-61 are presented and compared to shell model calculations.
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4. |
- Petts, A., et al.
(författare)
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Lifetime measurements and coulomb excitation of light Hg nuclei
- 2009
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Ingår i: Capture Gamma-Ray Spectroscopy and Related Topics. - : American Institute of Physics (AIP). - 9780735406230 ; , s. 414-418
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Konferensbidrag (refereegranskat)abstract
- Two complementary experimental programs have taken place to investigate the origin and evolution of shape coexistence in the light mercury region. Recoil Distance Doppler-shift measurements were performed at the University of Jyväskylä utilizing the Köln plunger device in conjunction with the JUROGAM + RITU + GREAT setup. In addition, Coulomb excitation measurements of 184,186,188Hg were performed at REX-ISOLDE using the MINIBALL Ge-detector array. The results of the lifetime measurements of the yrast states up to Iπ = 10+ in 182Hg are reported. Preliminary analysis of the Coulomb excitation data is also discussed.
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5. |
- Bree, N., et al.
(författare)
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Coulomb Excitation of 68Ni at "safe" energies
- 2008
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 78
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Tidskriftsartikel (refereegranskat)abstract
- The B(E2;0+2+) value in 68Ni has been measured using Coulomb excitation at safe energies. The 68Ni radioactive beam was postaccelerated at the CERN on-line isotope mass separator (ISOLDE) facility to 2.9 MeV/u and directed to a 108Pd target. The emitted rays were detected by the MINIBALL detector array. Not only directly registered but also indirectly deduced information on the nucleus emitting the ray was used to perform the Doppler correction, leading to a larger center-of-mass angular range to infer the excitation cross section. The obtained value of 2.8×102e2 fm4 is in good agreement with the value measured at intermediate energy Coulomb excitation, confirming the low 0+2+ transition probability.
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