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| 2. |
- Ekström, Andreas, et al.
(författare)
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Coulomb excitation of Sn-110 using REX-ISOLDE
- 2006
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Ingår i: Physica Scripta. - 1402-4896 .- 0031-8949. ; T125, s. 190-191
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Konferensbidrag (refereegranskat)abstract
- In this paper, we report the preliminary result from the first Coulomb excitation experiment at REX-ISOLDE (Habs et al 1998 Nucl. Instrum. Methods B 139 128) using neutron-deficient Sn-beams. The motivation of the experiment is to deduce the reduced transition probability, B(E2; 2(+) -> 0(+)), for the sequence of neutron deficient, unstable, even-even Sn- isotopes from Sn-110 to ultimately Sn-110. Safe Coulomb excitation using a radioactive beam opens up a new path to study the lifetime of the first excited 2(+) state in these isotopes. The de-excitation path following fusion-evaporation reactions will for the even-even Sn isotopes pass via an isomeric 6(+) state, located at higher energy, which thus hampers measurements of the lifetime of the first excited state using, e. g., recoil-distance methods. For this reason the reduced transition probability of the first excited 2(+) state has remained unknown in this chain of isotopes although the B(E2) value of the stable isotope Sn-112 was measured approximately 30 years ago (see, e. g., Stelson et al 1970 Phys. Rev. C 2 2015). Our experiment is thus the first to accomplish a measurement of this quantity in Sn-110. It is believed that the determination of the B(E2) value in Sn-110 will indicate the turnover point from a trend of increasing B(E2) values for the heavier isotopes to a trend characterized by less collectivity. Our first preliminary result indicates that this assumption may well be correct.
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| 3. |
- Ekström, Andreas, et al.
(författare)
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Sub-barrier Coulomb excitation of Sn-106,Sn-108,Sn-110
- 2008
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Ingår i: Frontiers in Nuclear structure, Astrophysics and Reactions - Finustar 2, AIP Conference Proceedings. - : AIP. - 0094-243X .- 1551-7616. ; 1012, s. 296-299
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Konferensbidrag (refereegranskat)abstract
- The reduced transition probabilities between the first excited 2(+) state and the 0(+) ground state, B(E2; 0(+) -> 2(+)), have been measured in Sn-106,Sn-108,Sn-110 using sub-barrier Coulomb excitation in inverse kinematics at REX-ISOLDE. The results are, B(E2;0(+) -> 2(+)) = 0.220(22),0.226(17), and 0.228(32) e(2)b(2), for Sn-110, Sn-108, and Sn-106, respectively. The results for Sn-106,Sn-108 are preliminary. De-excitation gamma-rays were detected by the MINIBALL Ge-array. The B(E2) reveals detailed information about the nuclear wave function. A shell model prediction based on an effective CD-Bonn interaction in the nu(0g(7/2),2s, 1d, 0h(11/2)) model space using e(eff)(nu) =1.0 e follows the experimental values for the neutron rich Sn isotopes, but fails to reproduce the results presented here.
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| 4. |
- Forsberg, Ulrika, et al.
(författare)
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Spectroscopic Tools Applied to Element Z = 115 Decay Chains
- 2014
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Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X .- 2101-6275. - 9782759811755 - 9782759811762 ; 66, s. 02036-02036
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Konferensbidrag (refereegranskat)abstract
- Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.
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| 5. |
- Johansson, Emma, et al.
(författare)
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Prompt Proton Decay in the Vicinity of 56Ni
- 2007
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Ingår i: Proton Emitting Nuclei and Related Topics. - : AIP. - 1551-7616 .- 0094-243X. ; 961, s. 41-46
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Konferensbidrag (refereegranskat)abstract
- A new decay mode, the so called prompt proton decay, was discovered in 1998. It has since proven to be an important decay mechanism for several neutron deficient nuclei in the A similar to 60 region. To measure with high accuracy the energies and angular distributions of these protons, a state-of-the-art charged particle detector - LuWuSiA - was developed. It was first utilized during a fusion-evaporation reaction experiment performed at Argonne National Laboratory, U.S.A. In this contribution, the characteristics of the prompt proton decay are discussed along with the special features of LuWuSiA as well as a revisit to the prompt proton decay in Cu-58.
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| 6. |
- Batani, D., et al.
(författare)
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Effects of laser prepulse on proton generation
- 2010
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 620:1, s. 76-82
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Konferensbidrag (refereegranskat)abstract
- Low-intensity laser prepulse ( < 10(13) W/cm(2), ns duration) are a major issue in experiments on laser-generation of protons, often limiting the performances of proton sources produced by high-intensity lasers (approximate to 10(19) W/cm(2), ps or fs duration) Several effects are associated to the prepulse and are discussed in this contribution: i) Destruction of thin foil targets by the shock generated by the laser prepulse ii) Creation of preplasma on target front side affecting laser absorption iii) Deformation of target rear side iv) Whole displacement of thin foil targets affecting focusing condition In particular, we show that under oblique high-intensity irradiation and for low prepulse intensities, the proton beam is directed away from the target normal. Deviation is towards the laser forward direction, with an angle that increases with the level and duration of the ASE pedestal. Also, for a given laser pulse, beam deviation increases with proton energy. The observations are discussed in terms of Target Normal Sheath Acceleration, in combination with a laser-controllable shock wave locally deforming the target surface. (C) 2010 Elsevier B.V. All rights reserved.
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| 7. |
- Batani, D., et al.
(författare)
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Effects of laser prepulse on proton generation
- 2010
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Ingår i: Radiation Effects and Defects in Solids. - : Informa UK Limited. - 1042-0150 .- 1029-4953. ; 165:6-10, s. 794-802
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Konferensbidrag (refereegranskat)abstract
- Prepulse is a major issue for laser generation of protons, often limiting the performances of laser sources. Here, we show the use of prepulse (1013W/cm2, ns duration) to actively manipulate the proton beam direction. Under oblique high-intensity irradiation (approximate to 1019W/cm2, ps duration) of the thin foil target, and for low prepulse intensities, the proton beam is directed away from the ounperturbedo target normal. Observations are discussed in terms of target normal sheath acceleration, in combination with a laser-controllable shock locally deforming the target surface.
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| 8. |
- Carroll, D. C., et al.
(författare)
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A modified Thomson parabola spectrometer for high resolution multi-MeV ion measurements-Application to laser-driven ion acceleration
- 2010
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 620:1, s. 23-27
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Konferensbidrag (refereegranskat)abstract
- A novel Thomson parabola ion spectrometer design is presented, in which a gradient electric field configuration is employed to enable a compact design capable of high resolution measurements of ion energy and charge-to-mass ratio. Practical issues relating to the use of the spectrometer for measurement of ion acceleration in high-power laser-plasma experiments are discussed. Example experimental results for ion acceleration from petawatt-class laser interactions with thin gold target foils are presented. (C) 2010 Elsevier B.V. All rights reserved.
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| 9. |
- Gadea, A., et al.
(författare)
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Spectroscopy at N=Z with EUROBALL III
- 1999
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. ; 495, s. 195-198
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Konferensbidrag (refereegranskat)abstract
- A complete study of the nuclear structure by means of gamma spectroscopy requires, in addition to the high resolution gamma measurement and accurate DCO's or angular distributions, the information concerning the Electric or Magnetic character of the transition. This information for transitions in nuclei far from stability valley is now reachable in the new generation of Ge-arrays based in composite detectors. EUROBALL III is a good example with the high polarization sensitivity of the 90 degrees ring of Clovers. The Polarization correlations PCO's measured in coincidence with the Cluster detectors permits to investigate transitions in weakly populated nuclei. In this contribution we present results on medium mass N=Z nuclei measured with EUROBALL III coupled with light particle ancillary detectors.
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| 10. |
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