| 1. |
- Illana, A., et al.
(författare)
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Coulomb excitation of 74,76Zn
- 2023
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Ingår i: Physical Review C. - 2469-9985. ; 108:4
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Tidskriftsartikel (refereegranskat)abstract
- The first experiment using radioactive beams post-accelerated by the HIE-ISOLDE facility has enabled to obtain a precise set of B(E2) transition probabilities in neutron-rich 74,76Zn isotopes. The resulting B(E2; 2+1→0+1) values are consistent with those determined in earlier REX-ISOLDE measurements. While the B(E2; 4+1→2+1) transition probability in 76Zn is also in agreement with earlier Coulomb-excitation results, the value obtained for 74Zn is considerably lower. For the first time, a spectroscopic quadrupole moment of the 2+1 state was measured for an exotic nucleus in this mass region. A detailed comparison is presented with large-scale shell-model and Monte Carlo shell-model calculations.
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| 2. |
- Urquiza-González, M., et al.
(författare)
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Benchmark evaluation for a single frequency continuous wave OPO seeded pulsed dye amplifier for high-resolution laser spectroscopy
- 2023
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9781510659032
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Konferensbidrag (refereegranskat)abstract
- The study of the atomic spectrum via resonant laser excitation provides access to underlying effects caused by the nuclear structure, which is of special interest in short-lived radioisotopes produced at Isotope Separator On-Line (ISOL) facilities. Current implementations of resonant laser ionization techniques often limit the extraction of the nuclear observables due to the low spectral resolution of the pulsed laser systems deployed. Several high-resolution spectroscopy techniques demand spectral widths in the order of hundreds of MHz and below. A proven solution to reduce this linewidth is the pulsed amplification of a narrow-band continuous wave (cw) laser. This work presents the demonstration of a pulsed dye amplifier seeded by a commercially available cw Optical Parametric Oscillator (OPO). The performance of this system was compared with competing setups using a cw dye laser seed source as well as a frequency mixing technique using a combination of an injection-locked titanium:sapphire (Ti:Sa) and a Nd:YVO4 laser. Spectral bandwidths of the systems were measured using a high finesse Fabry-Perot Interferometer, resulting in comparable optical linewidths between 140 to 156 MHz at a wavelength of 328 nm for the different laser setups. Suitability for on-line experiments was validated by performing high-resolution spectroscopy of radioactive silver isotopes in the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the Isotope Separator On-Line Device (ISOLDE), at the European Organization for Nuclear Research (CERN). The quality of the hyperfine spectra was similar for the dye and the OPO seed and the deduced hyperfine splitting was in good agreement with literature, while the frequency mixing technique exhibited less precise results attributed to the frequency instabilities and mode-hops of the single-mode Nd:YVO4 laser.
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| 3. |
- Au, M., et al.
(författare)
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In-source and in-trap formation of molecular ions in the actinide mass range at CERN-ISOLDE
- 2023
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Ingår i: Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms. - 0168-583X. ; 541, s. 375-379
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Tidskriftsartikel (refereegranskat)abstract
- The use of radioactive molecules for fundamental physics research is a developing interdisciplinary field limited dominantly by their scarce availability. In this work, radioactive molecular ion beams containing actinide nuclei extracted from uranium carbide targets are produced via the Isotope Separation On-Line technique at the CERN-ISOLDE facility. Two methods of molecular beam production are studied: extraction of molecular ion beams from the ion source, and formation of molecular ions from the mass-separated ion beam in a gas-filled radio-frequency quadrupole ion trap. Ion currents of U+, UO1-3+, UC1-3+, UF1-4+, UF1,2O1,2+ are reported. Metastable tantalum and uranium fluoride molecular ions are identified. Formation of UO1-3+, U(OH)1-3+, UC1-3+, UF1,2O1,2+ from mass-separated beams of U+, UF1,2+ with residual gas is observed in the ion trap. The effect of trapping time on molecular formation is presented.
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| 4. |
- Rothe, S., et al.
(författare)
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Targets and ion sources at CERN-ISOLDE - Facilities and developments
- 2023
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Ingår i: Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms. - 0168-583X. ; 542, s. 38-44
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Tidskriftsartikel (refereegranskat)abstract
- At the CERN-ISOLDE radioactive ion beam facility, thick targets are irradiated using a beam of 1.4-GeV protons. One of ISOLDE's key features is the large choice of ion source types and target materials available, enabling us to select the ideal combination for optimal intensity and purity of the isotopes requested by ISOLDE users. The ever-increasing demands in terms of isotope production yield, beam purity, and overall reliability of the employed systems are driving the continuous development efforts.Over the past few years, CERN has invested heavily in facilities and infrastructure that facilitate ongoing developments required for ISOLDE. A dedicated offline laboratory (Offline 2) has been recently equipped with high repetition rate nanosecond tunable lasers required for scheme development and developments of specialized laser ion source types such as VADLIS, LIST and PI-LIST. Moreover, it hosts a twin setup of the ISOLDE RFQ cooler and buncher (ISCOOL), which is envisaged to be used for studies of molecular beam creation and breakup, as well as the development of improved RFQ services and operational modes. For material development, particularly for nanostructured materials, the new nano laboratory has just been commissioned and will enable the production and development of nano actinide targets for ISOLDE. In this contribution we describe the infrastructure required for target and ion source developments, highlight recent efforts and experimental results on both target material development and ion source development, and provide an outlook on what to expect in the near future.
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