| 1. |
- Grieser, M., et al.
(author)
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Storage ring at HIE-ISOLDE Technical design report
- 2012
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In: The European Physical Journal Special Topics. - : Springer Science and Business Media LLC. - 1951-6355 .- 1951-6401. ; 207:1, s. 1-117
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Research review (peer-reviewed)abstract
- We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report.
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| 2. |
- Bruce, A. M., et al.
(author)
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Beta Decay of 102Y Produced in Projectile Fission of 238U
- 2012
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 381
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Journal article (peer-reviewed)abstract
- The population of 102Zr following the β decay of 102Y produced in the projectile fission of 238U at the GSI facility in Darmstadt, Germany has been studied. 102Y is known to ß decay into 102Zr via two states, one of high spin and the other low spin. These states preferentially populate different levels in the 102Zr daughter. In this paper the intensities of transitions in 102Zr observed are compared with those from the decay of the low-spin level studied at the TRISTAN facility at Brookhaven National Laboratory and of the high-spin level studied at the JOSEF separator at the Kernforschungsanlage Jülich.
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| 3. |
- Grieser, M., et al.
(author)
-
Storage ring at HIE-ISOLDE
- 2012
-
In: European Physical Journal: Special Topics. - : Springer Science and Business Media LLC. - 1951-6401 .- 1951-6355. ; 207:1, s. 1-117
-
Journal article (peer-reviewed)abstract
- We propose to install a storage ring at an ISOL-type radioactive beam facility for the first time. Specifically, we intend to setup the heavy-ion, low-energy ring TSR at the HIE-ISOLDE facility in CERN, Geneva. Such a facility will provide a capability for experiments with stored secondary beams that is unique in the world. The envisaged physics programme is rich and varied, spanning from investigations of nuclear ground-state properties and reaction studies of astrophysical relevance, to investigations with highly-charged ions and pure isomeric beams. The TSR might also be employed for removal of isobaric contaminants from stored ion beams and for systematic studies within the neutrino beam programme. In addition to experiments performed using beams recirculating within the ring, cooled beams can also be extracted and exploited by external spectrometers for high-precision measurements. The existing TSR, which is presently in operation at the Max-Planck Institute for Nuclear Physics in Heidelberg, is well-suited and can be employed for this purpose. The physics cases as well as technical details of the existing ring facility and of the beam and infrastructure requirements at HIE-ISOLDE are discussed in the present technical design report.
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| 4. |
- Wadsworth, R., et al.
(author)
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Spin-gap Isomer in 96Cd
- 2012
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 381:1
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Journal article (peer-reviewed)abstract
- Evidence has been obtained for the existence of the long predicted 16+ spin-gap isomer in 96Cd. The decay of the isomer was identified and studied following the use of an 850 MeV/u beam of 124Xe impinging on a Be target and the fragment recoil separator at the GSI Laboratory. Gamma decays from the fragments were detected using the RISING gamma ray array, in its stopped beam configuration, plus a silicon active stopper. The data obtained have been compared with shell model predictions, which indicate that the isoscalar neutron-proton interaction plays a key role in the formation of the isomer.
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| 5. |
- Bree, N, et al.
(author)
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Shape Coexistence in the Neutron-Deficient Even-Even Hg182-188 Isotopes Studied via Coulomb Excitation.
- 2014
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In: Physical Review Letters. - 1079-7114. ; 112:16
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Journal article (peer-reviewed)abstract
- Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with 2.85 MeV/nucleon mercury beams from REX-ISOLDE. Magnitudes and relative signs of the reduced E2 matrix elements that couple the ground state and low-lying excited states in Hg182-188 were extracted. Information on the deformation of the ground and the first excited 0+ states was deduced using the quadrupole sum rules approach. Results show that the ground state is slightly deformed and of oblate nature, while a larger deformation for the excited 0+ state was noted in Hg182,184. The results are compared to beyond mean field and interacting-boson based models and interpreted within a two-state mixing model. Partial agreement with the model calculations was obtained. The presence of two different structures in the light even-mass mercury isotopes that coexist at low excitation energy is firmly established.
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| 6. |
- Cocolios, T. E., et al.
(author)
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Early onset of deformation in the neutron-deficient polonium isotopes
- 2012
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In: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 381:1, s. 012072-
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Journal article (peer-reviewed)abstract
- In-source laser spectroscopy has been performed at CERN-ISOLDE with the RILIS laser ion source on 191-204,206,208-211,216,218Po. New information on the β decay of 199Po were extracted in the process, challenging previous results. Large-scale atomic calculations were performed to extract the changes in the mean-square charge radius δr 2 from the isotope shifts. The δ«r» 2 for the even-A isotopes reveal a large deviation from the spherical droplet model for N < 116.
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| 7. |
- Cocolios, T. E., et al.
(author)
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Early Onset of Ground State Deformation in Neutron Deficient Polonium Isotopes
- 2011
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 106:5, s. 052503-
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Journal article (peer-reviewed)abstract
- In-source resonant ionization laser spectroscopy of the even-A polonium isotopes Po-192-210,Po-216,Po-218 has been performed using the 6p(3)7s S-5(2) to (6)p(3)7p P-5(2) (lambda = 843.38 nm) transition in the polonium atom (Po-I) at the CERN ISOLDE facility. The comparison of the measured isotope shifts in Po200-210 with a previous data set allows us to test for the first time recent large-scale atomic calculations that are essential to extract the changes in the mean-square charge radius of the atomic nucleus. When going to lighter masses, a surprisingly large and early departure from sphericity is observed, which is only partly reproduced by beyond mean field calculations.
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| 8. |
- Cocolios, T. E., et al.
(author)
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Structure of Pb-191 from alpha- and beta-decay spectroscopy
- 2010
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In: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 37:12, s. 125103-
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Journal article (peer-reviewed)abstract
- Complementary studies of Pb-191 have been made in the beta decay of Bi-191 at LISOL (CRC) and in the alpha decay of Po-195 at ISOLDE (CERN). Fine structures in the alpha decay of the low-spin and high-spin isomers of 195Po have been fully resolved. Identification of the parent state is made possible via isomer selection based on narrow-band laser frequency scanning. The alpha-particle and gamma-ray energies have been determined with greater precision. New alpha-particle and. gamma-ray energies are identified. Branching ratios in the decay of Po-195 and Pb-191 have been examined.
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| 9. |
- Seliverstov, M. D., et al.
(author)
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Charge radii of odd-A Po191-211 isotopes
- 2013
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In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 719:4-5, s. 362-366
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Journal article (peer-reviewed)abstract
- Isotope shifts have been measured for the odd-A polonium isotopes Po191-211 and changes in the nuclear mean square charge radii delta < r(2 >) have been deduced. The measurements were performed at CERN-ISOLDE using the in-source resonance-ionization spectroscopy technique. The combined analysis of these data and our recent results for even-A polonium isotopes indicates an onset of deformation already at Po-197,Po-198, when going away from stability. This is significantly earlier than was suggested by previous theoretical and experimental studies of the polonium isotopes. Moreover and in contrast to the mercury isotopes, where a strong odd-even staggering of the charge radii of the ground states was observed by approaching the neutron mid-shell at N = 104, no such effect is present in polonium down to Po-191. Consequently the charge radii of both isomeric and ground states of the odd-A polonium isotopes follow the same trend as the even-A isotopes.
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| 10. |
- Seliverstov, M. D., et al.
(author)
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Electromagnetic moments of odd-A Po-193-203,Po-211 isotopes
- 2014
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In: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 89:3, s. 034323-
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Journal article (peer-reviewed)abstract
- Hyperfine splitting parameters have been measured for the neutron-deficient odd-mass polonium isotopes and isomers Po-193-203(g,m), Po-209,Po-211. The measurement was performed at the ISOLDE (CERN) online mass separator using the in-source resonance ionization spectroscopy technique. The magnetic dipole moments mu and spectroscopic electric quadrupole moments Q(S) have been deduced. Their implication for the understanding of nuclear structure in the vicinity of the closed proton shell at Z = 82 and the neutron mid-shell at N = 104 is discussed. For the most neutron-deficient nuclei (A = 193,195,197), a deviation of mu and QS from the nearly constant values for heavier polonium nuclei was observed. Particle-plus-rotor calculations with static oblate deformation describe the electromagnetic moments for these nuclei well, provided a gradual increase of a mean deformation when going to lighter masses is assumed for the polonium nuclei with A < 198.
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