Blurring the boundaries between ion sources: The application of the RILIS inside a FEBIAD type ion source at ISOLDE

Goodacre, T. Day; Billowes, J.; Catherall, R.; Cocolios, T. E.; Crepieux, B.; Fedorov, D. V.; Fedosseev, V. N.; Gaffney, L. P.; Giles, T.; Gottberg, A.; Lynch, K. M.; Marsh, B. A.; Mendonça, Tânia; Ramos, J.P.; Rossel, R. E.; Rothe, S.; Sels, S.; Sotty, Ch.; Stora, T.; Beveren, C. Van; Veinhard, Matthieu

doi:10.1016/j.nimb.2016.03.005

Cited by 27 publications

(19 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work, we report the first study of single-neutron excitations beyond N = 126 for elements below Pb, achieved using a transfer reaction in inverse kinematics with a radioactive beam of 206 Hg, accelerated to energies above the Coulomb barrier for collisions with deuterium. This study was made possible by new advances in technology at the ISOLDE radioactive-beam facility at CERN [33][34][35] and with the development of the ISOLDE Solenoidal Spectrometer (ISS) [36] based on a technique pioneered at Argonne National Laboratory (ANL). As was demonstrated with HELIOS at ANL [37], factors of 2-3 improvements in Q-value resolution can be achieved in the study of these types of reactions using the solenoidal-spectrometer technique [38,39].…”

mentioning

confidence: 99%

First Exploration of Neutron Shell Structure below Lead and beyond N=126

Tang¹,

Kay²,

Hoffman³

et al. 2020

Phys. Rev. Lett.

View full text Add to dashboard Cite

The nuclei below lead but with more than 126 neutrons are crucial to an understanding of the astrophysical r-process in producing nuclei heavier than A ∼ 190. Despite their importance, the structure and properties of these nuclei remain experimentally untested as they are difficult to produce in nuclear reactions with stable beams. In a first exploration of the shell structure of this region, neutron excitations in 207 Hg have been probed using the neutron-adding (d,p) reaction in inverse kinematics. The radioactive beam of 206 Hg was delivered to the new ISOLDE Solenoidal Spectrometer at an energy above the Coulomb barrier. The spectroscopy of 207 Hg marks a first step in improving our understanding of the relevant structural properties of nuclei involved in a key part of the path of the r-process.The nucleus 207 Hg lies in the almost completely unexplored region of the nuclear chart below proton number 82 and just above neutron number 126, both "magic" numbers representing closed shells in the nuclear shell model [1]. The doubly-magic nucleus 208 Pb is the cornerstone of this region, a benchmark nucleus in our understanding of the single-particle foundation of nuclear structure. This region, highlighted on the nuclear chart in Fig. 1, is unique in that its single-particle structure remains unexplored.The nucleosynthesis of heavy elements via the rapid neutron-capture (r-) process path [2] crosses this region, as shown in Fig. 1. The robustness of the N = 126 neutron shell closure plays a crucial role in the nucleosynthesis of the actinides [3][4][5][6][7]. The recent observation of a neutron star merger has provided a new focus of interest [8,9], suggesting a possible astrophysical environment for r-process nucleosynthesis [10-13].Approaching the r-process path along the N = 126 isotonic chain from Pb, the binding energies (the degree to which neutrons are bound by the mean-field potential created by the decreasing number of all other nucleons) decrease, eventually crossing zero binding and becoming unbound. Near closed shells, the level density is low, so the usual statistical assumptions of many resonances participating in neutron capture is not valid, and specific nuclear-structure properties become important. Knowledge of ground-state binding energies of nuclei with N = 126 + n is important in defining the waiting point caused by the N = 126 closure, the bottleneck which is responsible for the third peak in solar system elemental abundances at nuclear mass A ∼ 195 [14]. The binding energies are critical to how the r-process evolves. The energies of ground and excited states have significant consequences for the rate at which direct s-, p-, (and possibly d-) wave neutron-capture (n,γ) reactions proceed [15][16][17]. This was discussed recently in the context of the N = 82 shell closure in Ref. [18].As zero binding is approached, the energies of s orbitals increase less rapidly than those of states with higher angular momenta [19]. This behavior has been studied for light nuclei [20,21] and, in the vicinity o...

show abstract

mentioning

confidence: 99%

First Exploration of Neutron Shell Structure below Lead and beyond N=126

Tang¹,

Kay²,

Hoffman³

et al. 2020

Phys. Rev. Lett.

View full text Add to dashboard Cite

show abstract

“…In section 2 we describe the basic principles of the RILIS method including the ionization process in a hot tubular metal cavity and the laser system itself. Newly developed approaches, such as the laser ion source and trap (LIST) [19] and the versatile arc discharge and laser ion source (VADLIS) [20] are described in section 3. Section 4 is devoted to RILIS applications which, in addition to the standard mode of RILIS operation for efficient and selective ionization of a requested element, includes the operation of the RILIS lasers in a highresolution mode for laser probing of different isotopes and nuclear isomers of the chosen element.…”

mentioning

confidence: 99%

Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

Fedosseev

Wendt

Rothe

et al. 2017

J. Phys. G: Nucl. Part. Phys.

128

View full text Add to dashboard Cite

Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation.Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and Made open access 7 August 2017Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments.

show abstract

“…The mercury scheme has already been applied at ISOLDE for a successful in-source resonance ionization spectroscopy experiment. The scheme was demonstrated to have an ionization efficiency equivalent to that of the ISOLDE VADIS ion source under standard on-line conditions [18]. The application of the new mercury scheme has been requested for a number of future ISOLDE experiments, due to the selective method of ionization offered by the RILIS.…”

Section: Discussionmentioning

confidence: 99%

“…Following these results, the new RILIS scheme was applied using the anode cavity of a VADIS (ISOLDE's FEBIAD type) ion source as the laser atom interaction region, described in [18]. The extracted mercury ion currents when using either the arc discharge ionization process or the element selective RILIS ionization process were found to be equivalent, suggesting a comparative efficiency under on-line conditions.…”

Section: Rilis Ionization Efficiency Of Mercurymentioning

confidence: 97%

RILIS-ionized mercury and tellurium beams at ISOLDE CERN

et al. 2017

Self Cite

View full text Add to dashboard Cite

This paper presents the results of ionization scheme development for application at the ISOLDE Resonance Ionization Laser Ion Source (RILIS). Two new ionization schemes for mercury are presented: a three-step three-resonance ionization scheme, ionizing via an excitation to a Rydberg level and a three-step two-resonance ionization scheme, with a non-resonant final step to the ionization continuum that corresponded to a factor of four higher ionization efficiency. The efficiency of the optimal mercury ionization scheme was measured, together with the efficiency of a new three-step three resonance ionization scheme for tellurium. The efficiencies of the mercury and tellurium ionization schemes were determined to be 6 % and >18 % respectively.

show abstract

Blurring the boundaries between ion sources: The application of the RILIS inside a FEBIAD type ion source at ISOLDE

Cited by 27 publications

References 17 publications

First Exploration of Neutron Shell Structure below Lead and beyond N=126

First Exploration of Neutron Shell Structure below Lead and beyond N=126

Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

RILIS-ionized mercury and tellurium beams at ISOLDE CERN

Contact Info

Product

Resources

About