| 1. |
- Rodriguez, L. , V, et al.
(författare)
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Doubly-magic character of Sn-132 studied via electromagnetic moments of( 13)(3)Sn
- 2020
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 102:5
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Tidskriftsartikel (refereegranskat)abstract
- We report the first measurement of the magnetic dipole and electric quadrupole moment of the exotic nucleus Sn-133 by high-resolution laser spectroscopy at ISOLDE/CERN. These, in combination with state-of-the-art shell-model calculations, demonstrate the single-particle character of the ground state of this short-lived isotope and, hence, the doubly-magic character of its immediate neighbor Sn-132. The trend of the electromagnetic moments along the N = 83 isotonic chain, now enriched with the values of tin, are discussed on the basis of realistic shell-model calculations.
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| 2. |
- Sels, S., et al.
(författare)
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Doppler and sympathetic cooling for the investigation of short-lived radioactive ions
- 2022
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Ingår i: Physical Review Research. - 2643-1564. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- At radioactive ion beam (RIB) facilities, ions of short-lived radionuclides are cooled and bunched in buffer-gas-filled Paul traps to improve the ion-beam quality for subsequent experiments. To deliver even colder ions, beneficial to RIB experiments' sensitivity or accuracy, we employ Doppler and sympathetic cooling in a Paul trap cooler-buncher. The improved emittance of Mg+, K+, and O2+ ion beams is demonstrated by a reduced time-of-flight spread of the extracted ion bunches with respect to room-temperature buffer-gas cooling. Cooling externally-produced hot ions with energies of at least 7 eV down to a few Kelvin is achieved in a timescale of O(100 ms) by combining a low-pressure helium background gas with laser cooling. This is sufficiently short to cool short-lived radioactive ions. As an example of this technique's use for RIB research, the mass-resolving power in a multireflection time-of-flight mass spectrometer is shown to increase by up to a factor of 4.6 with respect to buffer-gas cooling. Simulations show good agreement with the experimental results and guide further improvements and applications. These results open a path to a significant emittance improvement and, thus, unprecedented ion-beam qualities at RIB facilities, achievable with standard equipment readily available. The same method provides opportunities for future high-precision experiments with radioactive cold trapped ions.
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| 3. |
- Alfs, D., et al.
(författare)
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Drift chamber calibration and particle identification in the P-349 experiment
- 2019
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Ingår i: MESON 2018 - 15th International Workshop on Meson Physics. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- The goal of the P-349 experiment is to test whether 3.5 GeV/c antiprotons produced in high-energy proton-proton collisions are polarized in view of the preparation of a polarized antiproton beam. In this article, we present the details of the ongoing analysis focused on the drift chambers calibration and particle identification with DIRC.
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| 4. |
- Alfs, D., et al.
(författare)
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Drift Chamber Calibration And Track Reconstruction In The P349 Antiproton Polarization Experiment
- 2017
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 48:10, s. 1983-1988
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Tidskriftsartikel (refereegranskat)abstract
- The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.
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| 5. |
- Alfs, D., et al.
(författare)
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Status of the analysis for the search of polarization in the antiproton production process
- 2016
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Ingår i: MESON 2016 - 14th International Workshop On Meson Production, Properties And Interaction. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- The P-349 experiment aims to test whether for antiprotons the production process itself can be a source of polarization in view of the preparation of a polarized antiproton beam. In this article we present the details of performed measurements and report on the status of the ongoing analysis.
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| 6. |
- Grzonka, D., et al.
(författare)
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Polarization analysis of <(p)over bar> produced in pA collisions
- 2019
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Ingår i: MESON 2018 - 15th International Workshop on Meson Physics. - : EDP Sciences.
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Konferensbidrag (refereegranskat)abstract
- A quite simple procedure for the generation of a polarized antiproton beam could be worked out if antiprotons are produced with some polarization. In order to investigate this possibility measurements of the polarization of produced antiprotons have been started at a CERN/PS test beam. The polarization will be determined from the asymmetry of the elastic antiproton scattering at a liquid hydrogen target in the CNI region for which the analyzing power is well known. The data are under analysis and an additional measurement is done in 2018. Details on the experiment and the ongoing data analysis will be given.
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| 7. |
- Grzonka, D., et al.
(författare)
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Search for Polarization Effects in the Antiproton Production Process
- 2015
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 46:1, s. 191-201
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Tidskriftsartikel (refereegranskat)abstract
- For the production of a polarized antiproton beam, various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization, a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.
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| 8. |
- Grzonka, D., et al.
(författare)
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Search for polarized antiproton production
- 2019
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Ingår i: Hyperfine Interactions. - : Springer Nature. - 0304-3843 .- 1572-9540. ; 240
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Tidskriftsartikel (refereegranskat)abstract
- The production of antiprotons is studied in view of possible polarization effects as basis for a polarized antiproton beam. If antiprotons are produced with some polarization, a quite simple procedure for the generation of a polarized antiproton beam could be worked out. The experiments are performed at the CERN PS test beam T11 where secondary particles with momenta around 3.5 GeV/c are selected. The polarization analysis is performed by measuring the asymmetry of the elastic (p) over barp-scattering in the Coulomb-nuclear interference region. The detection system includes Cherenkov and tracking detectors for the particle identification and the 3d track reconstruction. Details on the detection system and the status of the analysis are given.
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| 9. |
- Wraith, Calvin, et al.
(författare)
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Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers
- 2017
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 771, s. 385-391
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Tidskriftsartikel (refereegranskat)abstract
- Collinear laser spectroscopy was performed on Zn (Z = 30) isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N = 33–49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N = 50. Exactly one longlived (>10 ms) isomeric state has been established in each 69–79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell–model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ = 1/2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction.The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N = 43, while the progression towards 79Zn points to the stability of the Z = 28 and N = 50 shell gaps, supporting the magicity of 78Ni
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| 10. |
- Xie, L., et al.
(författare)
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Nuclear charge radii of Zn62-80 and their dependence on cross-shell proton excitations
- 2019
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 797
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear charge radii of Zn62-80 have been determined using collinear laser spectroscopy of bunched ion beams at CERN-ISOLDE. The subtle variations of observed charge radii, both within one isotope and along the full range of neutron numbers, are found to be well described in terms of the proton excitations across the Z = 28 shell gap, as predicted by large-scale shell model calculations. It comprehensively explains the changes in isomer-to-ground state mean square charge radii of Zn69-79, the inversion of the odd-even staggering around N = 40 and the odd-even staggering systematics of the Zn charge radii. With two protons above Z = 28, the observed charge radii of the Zn isotopic chain show a cumulative effect of different aspects of nuclear structure including single particle structure, shell closure, correlations and deformations near the proposed doubly magic nuclei, Ni-68 and Ni-78. (C) 2019 The Author(s). Published by Elsevier B.V.
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