PLATAN 2024 - Merger of the Poznan Meeting on Lasers and Trapping Devices in Atomic Nuclei Research and the International Conference on Laser Probing

9 Jun 2024, 12:00 → 14 Jun 2024, 18:25 Europe/Helsinki

A102 (Agora, University of Jyväskylä, Finland)

Mikael Reponen (University of Jyvaskyla (FI))

Dear Colleagues,

As local organizers, we would like to cordially invite you to participate to in the upcoming PLATAN 2024 meeting. PLATAN 2024 will serve as interdisciplinary forum for exchange between experimental and theoretical researchers and students in the research areas such as

• tests of fundamental interactions and symmetries using lasers and traps
• structural properties of elementary particles, nuclei & atoms using laser & storage techniques
• laser ion sources at hot cavities, gas cells and jets
• precision laser spectroscopy
• high-precision mass spectrometry
• spectroscopic routes to heavy and super-heavy elements
• production and spectroscopy of exotic atoms
• trace analysis by nuclear fingerprints
• cooling and trapping techniques devoted to exotic ion beams
• development and applications of gas catchers, ion guides and gas-jets
• dedicated laser sources for atomic and nuclear research
• applications

Looking forward to welcome you in Jyväskylä in June 2024!

Best regards,

Anu Kankainen and Iain Moore 

The PLATAN 2024 conference is sponsored by:

 

PLATAN-2024_final circular.pdf

PLATAN-2024_first circular.pdf

PLATAN-2024_second circular.pdf

Sunday 9 June

12:30 → 14:00 Tutorial: I

Convener: Tommi Eronen

14:00 → 14:30 Break with refreshments

14:30 → 16:00 Tutorial: II

Convener: Liss Vazquez Rodriguez (Max Planck Society (DE))

17:30 → 20:00 Welcome reception and registration

Monday 10 June

08:00 → 08:45 Registration

08:45 → 09:00 Opening the conference

09:00 → 10:30 Plenary: 1

Convener: Paul Campbell

09:00 Laser Spectoscopy of $^{208}$Bi$^{82+}$ at the Experimental Storage Ring ESR

Laser spectroscopy of highly charged ions at the Experimental Storage Ring (ESR) at GSI has a long tradition and started in 1994 with the observation of the hyperfine transition in $^{209}$Bi$^{82+}$ [1]. While carried out to test QED in the strongest magnetic fields available in the laboratory, it turned out that uncertainties in the nuclear structure contributions, specificially the nuclear magnetic moment distribution (Bohr-Weisskopf effect), completely cover the QED contributions. In order to escape this problem, it was suggested to combine the measurement in H-like Bi with a corresponding measurement in the Li-like ion to remove the nuclear cotributions in a specific difference $\Delta ^\prime E$ of the two hyperfine splitting energies [2]. The first precise determination of $\Delta^\prime E$ revealed a more than $7\sigma$ deviation between experiment and theory [3]. This could be resolved by an NMR redetermination of the nuclear magnetic moment of $^{209}$Bi [4], which is the only experimental input parameter into the calculation of $\Delta^\prime E$ and brought theory and experiment to agreement. In order to demonstrate the elimination of the BW effect in the specific difference, a measurement of $\Delta^\prime E$ for the isotope $^{208}$Bi has been proposed [5]. Here, I will present the first step of this endeavour, which was the successful measurement of the hyperfine splitting in $^{208}$Bi by the LIBELLE cooperation, which represents the very first laser spectroscopy of an artificially produced isotope at a storage ring.

[1]: I. Klaft et al., Phys. Rev. Lett. 73, 2425 (1994).
[2]: V. M. Shabaev, et al., Phys. Rev. Lett. 86, 3959 (2001).
[3]: J. Ullmann et al., Nat. Comm., 8, 15484 (2017).
[4]: L. Skripnikov et al., Phys. Rev. Lett. 120, 093001 (2018).
[5]: S. Schmidt, et al., Phys. Lett. B 779, 324 (2018).
Funding by BMBF under contract 05P21RDFA1 is acknowledged.

Speaker: Wilfried Nörtershäuser (Technische Universität Darmstadt (DE))

09:30 Two-body currents in magnetic dipole moments based on nuclear DFT

The electromagnetic (EM) moments and transitions in atomic nuclei provide fundamental insights into the nuclear structure and great progress has been achieved in past decades. However, the experimental deviation on EM moments and the 50-year-old quenching puzzle of beta decays indicate the impact of many-body contributions to the EM structure is non-negligible.
In recent years, the ab-initio calculations have explored the EM observables and weak transitions with contributions beyond the standard one-body operators. In Ref. [1], it is proposed that the missing nuclear correlations and the neglected contributions from meson-exchange currents are possible causes of the quenching phenomenon in beta decays.
More recently, Refs. [2, 3] focused on the magnetic moments from deuteron up to bismuth, including both manybody correlations and the leading EM two-body currents (2BC). On the other hand, the nuclear DFT can provide a global description of nuclear electric quadrupole and magnetic dipole moments, for example in one-particle and one-hole neighbors of doubly magic nuclei [4] or in open shell nuclei [5]. In our presentation, we introduce the first implementation of 2BC based on nuclear DFT in Jyväskylä-York collaboration to explore the contribution of higher-order current operators to magnetic dipole moments. The implementation is based on a use of auxiliary spherical harmonic oscillator basis, on which the two-body magnetic operator matrix elements are calculated. With use of unitary transformation, we can then compute the contribution of two-body currents on the magnetic moment for angular-momentum projected, deformed open shell nuclei. Further calculations are currently in progress.
[1] P. Gysbers et al., Nature Phys. 15, 428 (2019).
[2] R. Seutin et al., Phys. Rev. C 108, 054005 (2023).
[3] T. Miyagi et al., arXiv 2311, 14383 (2023).
[4] P. Sassarini et al., J. Phys. G Nucl. Part. Phys. 49, 11LT01 (2022).
[5] J. Bonnard et al., Phys. Lett. B 843, 138014 (2023)

platan2024_RuiHan.pdf

09:50 High-precision laser spectroscopy of helium-like carbon

The nuclear charge radius is a key observable in nuclear structure studies. Using the Collinear Apparatus for Laser Spectroscopy and Applied Physics (COALA) at the Institute of Nuclear Physics of TU Darmstadt, an all-optical approach for the nuclear charge radius determination was tested with the well-known nucleus of $^{12}$C. Here, the nuclear charge radius of $^{12}$C was extracted purely from laser spectroscopy measurements that were combined with non-relativistic QED calculations. Laser excitation of helium-like $^{12}$C$^{4+}$ started from the metastable $2 \,^3S_1$ state with a lifetime of 21 ms to reach the $2\,^3P_J$ states. The precision of the corresponding transition frequencies was improved by more than 3 orders of magnitude. Furthermore, this work represents the starting point for the necessary improvement of charge radii of the light-mass nuclei and it will be the corner stone for investigations of the carbon isotope chain. This contribution will give an overview of the project, present the measured transition frequencies along with the extracted all-optical nuclear charge radius of $^{12}$C and give an outlook on upcoming measurements. This project was supported by DFG (Project-ID 279384907 - SFB 1245) and by BMBF (05P21RDFN1).

Speaker: Phillip Imgram (KU Leuven (BE))

10.06.2024 - PLATAN2024.pdf

10:10 Nuclear structure of Pd isotopes via optical spectroscopy

High-resolution laser spectroscopy is a powerful tool to extract nuclear structure data in a nuclear-model-independent manner. The isotope shift gives direct access to changes in mean-square charge radii, while the extracted hyperfine parameters give access to the nuclear spin, magnetic dipole and electric quadrupole moment. All this provides information on e.g. deformation, shape coexistence and shell structure. Recently, measurements of ground state properties have also proven exceptionally potent in testing state-of-the-art nuclear theory.

The Pd isotopes are located in a transitional area between chains which display smooth trends in the charge radii (Sn region), and a region where the charge radii and electric quadrupole moments show evidence of a shape change at N=60, centred around yttrium. Between both however, i.e. Tc, Ru, Rh and Pd, no optical spectroscopic information has been available for radioactive nuclei so far. This is partly due to the refractory character of these elements, making production challenging for many facilities, but also their complex atomic structure.

At the IGISOL facility, these difficulties were overcome thanks to the chemically insensitive production method, and the installation of a charge-exchange cell. Collinear laser spectroscopy was performed on unstable Pd isotopes, known to be deformed from decay spectroscopy studies, although there is disagreement on the (possible) change in deformation. The measured nuclear charge radii, spins and electromagnetic moments [1,2] will be presented in this contribution, and the implication on the deformation will be discussed. Additionally, the results will be compared to Density Functional Theory (DFT) calculations using Fayans functionals. As most recent benchmarks of nuclear DFT were performed on spherical systems, close to (doubly-)magic systems, this presents a stringent test of the Fayans functionals for well-deformed isotopes.

[1] S. Geldhof et al., Phys. Rev. Lett. 128, 152501 (2022).
[2] A. Ortiz-Cortes, PhD thesis, University of Jyväskylä and Normandy University (2023).

Speaker: Sarina Geldhof (GANIL)

ppt-PLATAN-Geldhof.pdf

ppt-PLATAN-Geldhof.pptx

10:30 → 11:00 Coffee

11:00 → 12:30 Plenary: 2

Convener: Michael Block

11:00 Latest results from LEBIT and upgrades to the stopped beam facilities at FRIB

The Low-Energy Beam and Ion Trap (LEBIT) facility [1] at the recently commissioned Facility for Rare Isotope Beams (FRIB) remains the only facility that employs Penning trap mass spectrometry for high-precision mass measurements of rare isotopes produced via projectile fragmentation. This powerful combination of a fast, chemically insensitive rare isotope production method with a high-precision Penning trap mass spectrometer has yielded mass measurements of short-lived rare isotopes with precisions below 10 ppb across the chart of nuclides. The first LEBIT measurement campaigns in the FRIB era were a mass measurement of the proton dripline nucleus $^{22}$Al [2], a potential proton halo candidate, as well as providing an isomerically purified beam of $^{70}$Cu to the SuN total absorption spectrometer that was installed downstream of LEBIT.

To expand the experimental reach of Penning trap mass spectrometry to nuclides delivered at very low rates, the new Single Ion Penning Trap [3,4] (SIPT) has been built. SIPT uses narrowband FT-ICR detection under cryogenic conditions to perform mass measurements of high-impact candidates, delivered at rates as low as one ion per day, with only a single detected ion. Additional upgrades to the stopped beam facility at FRIB, including a high-resolution magnetic mass separator and high-performance MR-ToF will ensure that the mass measurement program will make optimal use of the wide range of rare isotope beams provided by FRIB.

[1] R. J. Ringle, S. Schwarz, and G. Bollen, Int. J. Mass Spectrom. 349-350, 87 (2013).
[2] S. Campbell, et al., Phys. Rev. Lett. 132, 152501 (2024).
[3] A. Hamaker, et al., Hyperfine Interact. 240, 34 (2019).
[4] S. Campbell et al., Atoms 11, 10 (2023).

Speaker: Ryan Ringle (Facility for Rare Isotope Beams/Michigan State University)

11:30 Shape Coexistence Near Doubly-Magic $^{78}$Ni

Investigating nuclear structure, especially nuclear shells and their associated magic numbers, has been an important field of research in the last decades. Such proton and neutron numbers are associated with sudden changes in nuclear observables between neighboring isotopes, such as binding energies, charge radii, transition strengths, etc. With $N=50$ neutrons and $Z=28$ protons, the $^{78}$Ni nucleus at the crossroads at two magic numbers is a prime candidate to test our understanding of the shell model [1]. Furthermore, the effect of shape coexistence, i.e. the existence of spherical ground states and deformed excited states, is often found in nuclei where intruder states across shell gaps lead to a large amount of deformation [2], indicating nearby magicity. Indication for shape coexistence in $^{79}$Zn with $N=49$ and $Z=30$ has previously been found through laser spectroscopy experiments [3] and in $^{80}$Ga with $N=49$ and $Z=31$ through electron-conversion spectroscopy [4]. The latter, however, was disproven in follow-up experiments [5,6]. In this contribution, we present further evidence for shape coexistence in $^{79}$Zn through the first direct excitation energy measurements of the ½+ isomeric state using Penning trap and multi-reflection time-of-flight mass spectrometry, firmly establishing the ½+ and 5/2+ state ordering [7]. Utilizing discrete nonorthogonal shell model calculations, we find low-lying deformed intruder states, similar to other $N=49$ isotones, and investigate similarities in shapes between excited states in $^{79,80}$Zn and $^{78}$Ni.

[1] R. Taniuchi et al., Nature (London) 569, 53 (2019).
[2] Garrett, Zielińska, and Clement, Prog. Part. Nucl. Phys. 124, 103931 (2022)
[3] Yang et al., PRL 116, 182502 (2016)
[4] Gottardo et al., PRL 116, 182501 (2016)
[5] Garcia et al., PRL 125, 172501 (2020)
[6] S. Sekal et al., Phys. Rev. C 104, 024317 (2021).
[7] Nies et al., PRL 131, 222503 (2023)

Speaker: Lukas Nies (CERN)

2024_06_10_PLATAN_LUKAS_NIES_ISOLTRAP-79Zn.pptx

11:50 Recent mass measurements of neutron-rich rare-earth nuclides with the JYFLTRAP double Penning Trap at IGISOL for the astrophysical r-process

High precision atomic mass spectrometry of neutron-rich rare-earth nuclides near A$\sim$165 was performed recently with the JYFLTRAP double Penning trap [1] using the phase-imaging ion cyclotron resonance technique [2] at the IGISOL facility in the JYFL Accelerator Laboratory. Altogether eighteen masses accross the lanthanum, terbium, dysprosium and holmium isotopic chains were measured, including the very first direct mass measurements of $^{152\text{,}153}$La, $^{169}$Tb and $^{170\text{,}171}$Dy. We continued the previous successful measurement campaigns at JYFLTRAP in this region [3,4] and now reached up to the N=104 neutron midshell, important for studying how the nuclear structure evolves further from stability. The properties of these nuclides also impact the models describing the formation of the rare-earth abundance peak around A$\sim$165 in the astrophysical rapid neutron capture (r) process [5], which has produced around half of the heavy-element abundances in the Solar System and takes place at least in neutron-star mergers. As variations in nuclear masses affect all the relevant nuclear properties of neighboring nuclei that depend on the mass, reducing their related uncertainties give better constraints on the calculated astrophysical reaction rates. The results are thus critical inputs for modelling the stellar nucleosynthesis and for understanding origins of different chemical elements and their abundances in the Solar System.

[1] T. Eronen et al., The European Physical Journal A 48 (2012) 46
[2] D. A. Nesterenko et al., The European Physical Journal A 54 (2018) 154
[3] M. Vilen et al., Physical Review Letters 120, 262701 (2018)
[4] M. Vilen et al., Physical Review C 101, 034312 (2020)
[5] M. Mumpower et al. Physical Review C 85, 045801 (2012)

Speaker: Arthur Jaries (University of Jyväskylä)

12:10 Pushing the Limits of Ab-Initio Theory through Precision Mass Measurements of Neutron Rich Potassium at TITAN

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is a set of connected ion traps for rare isotope science. TITAN operates a Multi-Reflection Time-Of-Flight Mass Spectrometer (MR-TOF-MS) primarily for nuclear mass measurements and isomerically selective ion beam cleaning. TITAN's MR-TOF-MS has demonstrated excellent dynamic range ($\sim10^8$), high-precision ($\frac{\delta m}{m} \sim 10^{-7}$) and high-speed ($\sim 5$ ms) mass measurements, allowing for the study of very exotic isotopes. Additionally, TITAN has developed new techniques enabling the measurement of half-lives using the MR-TOF-MS. This has allowed for half-life measurements of isotopes between $\sim$5 ms and $\sim$5 min. Concurrent decay detection with mass measurements as been developed as a routine tool for supplementary identification of rare isotope species at TITAN. TITAN's MR-TOF-MS's unique ability to self-purify ion beam through mass selective re-trapping has made this a particularly powerful technique for science at TITAN. Applications of these new techniques for the study of nuclear structure and nucleosynthesis will also be discussed.

TITAN has recently used the MR-TOF-MS to make a set of mass measurements clarifying the nuclear structure near N=34 in potassium. Experimental ground state masses are compared to new state of the art ab-initio calculations. This is used to benchmark the accuracy of novel nuclear interaction models near the neutron dripline.

Speaker: Coulter Walls (University of Manitoba)

12:30 → 14:00 Lunch

14:00 → 15:30 Plenary: 3

Convener: Tommi Eronen

14:00 Progress towards atomic parity violation measurements in francium

Low-energy precision tests of electro-weak physics keep playing an essential role in the search for new physics beyond the Standard Model. Atomic parity violation (APV) experiments measure the strength of highly forbidden atomic transitions induced by the exchange of Z bosons between electrons and quarks in heavy atoms. APV is sensitive to additional interactions such as leptoquarks, and provides complementary sensitivity to parity-violating electron scattering. Our group is working towards a measurement in francium, the heaviest alkali, where the APV signal is about 18 times lager than in cesium. Since Fr has no stable isotopes, we have established an online laser trap at the ISAC radioactive beam facility at TRIUMF that can confine millions of cold francium atoms at micro-Kelvin temperatures in a volume of approximately 1 cubic mm, an ideal environment for precision spectroscopy. Recently, we have observed the highly forbidden 7s-8s magnetic dipole transition, a final milestone prior to observing APV. I will review our recent work and present a roadmap for APV.

Speaker: Prof. Gerald Gwinner (University of Manitoba)

gwinner 2024.06.10 PLATAN francium.pdf

14:30 Parity-Violating Nuclear Effects From Single Molecules In A Penning Trap

This contribution will introduce a new experiment at MIT in which ion trapping and laser spectroscopy techniques are combined for precision measurements of fundamental symmetries and yet-to-be-explored nuclear electroweak properties [arXiv:2310.11192]. In particular, single trapped molecular ions can amplify the sensitivity to nuclear-spin-dependent parity-violating effects, such as the nuclear anapole moment, by more than 12 orders of magnitude compared to atoms. The current status and prospects for studying radioactive molecules will be discussed.

Speaker: Dr Jonas Karthein (Massachusetts Inst. of Technology (US))

14:50 Measurement of Analog-Antianalog Isospin Mixing in $^{47}$K Beta Decay

While both Charge-Parity (CP) symmetry, and more recently Time (T) symmetry have been directly shown to be violated in the weak interaction, it remains an open question whether new sources of CP violation could explain the matter-antimatter asymmetry in the universe. TRIUMF’s Neutral Atom Trap (TRINAT) is equipped to study the angular distribution of all decay products from spin-polarized beta emitting isotopes produced by the Isotope Separator and Accelerator (ISAC) facility. Decay from $^{47}$K (I=1/2) into the isobaric analog state is energetically forbidden, but instead 80% of the decays proceed via an isospin changing branch to a single I=1/2 state. The recoil asymmetry is made nonzero by the product of the Gamow-Teller and isospin-suppressed Fermi matrix elements, an effect we measured at TRINAT in order to test analog-antianalog isospin mixing.
We discuss the experiment and resulting magnitude of the Coulomb mixing of the candidate antilog 1/2$^+$ final state with the unbound isobaric analog resonance of $^{47g}$K. Our measurement was carried out by trapping approximately 10$^3$ laser-polarized $^{47}$K (t$_{1/2}$ = 17.5 $\pm$ 0.24 s) atoms at a time over the course of approximately one day.
A future measurement of $D I \cdot v_\beta \times v_\nu$ would have enhanced sensitivity to isospin-breaking, parity even, T-odd interactions, since they would be referenced to the Coulomb interaction. Furthermore, constraints from the neutron EDM on D [Ng, Tulin PRD 2012] are relaxed for such isospin-breaking interactions.

Speaker: Dr Brian Kootte (TRIUMF)

Brians_PLATAN_47K_presentation_upload_Jun2024.pdf

15:10 Current status of MORA at IGISOL

Around us we see an universe filled with galaxies, stars and planets like ours. But when we look back to the Big Bang and the processes that created the matter in it, at first we observe that there should have been created the same amount of matter and antimatter, thus the universe would be empty or different than it is. Sakharov suggested several conditions to explain the matter-antimatter asymmetry, one of them being the violation of the CP symmetry.

In the MORA experiment, we aim to measure the D correlation, which is non zero for violation of T symmetry in polarized nuclei, thus it can be related to CPV. For this we use a detector setup made of MCP’s, Phoswiches and Si detectors, to measure coincidences between beta emissions and recoil ions, product of the beta decay of trapped 23Mg ions.

Here I will present an introduction to D correlation, how we acquired the latest data in JYFL, how we analyzed it and the results we got concerning the calibration of detectors and polarization measurement.

Speaker: Luis Miguel Motilla Martinez

15:30 → 16:00 Coffee

16:00 → 17:30 Plenary: 4

Convener: Shuichi HASEGAWA (The University of Tokyo)

16:00 Present status and future prospects of SCRIT electron scattering facility

The world's first electron scattering off online-produced Radioisotope (RI) was successfully conducted at the SCRIT (Self-Confining RI Ion Target) electron scattering facility in RIKEN RI Beam Factory in Japan.
Electron scattering stands out as one of the most potent and reliable tools for investigating the structure of atomic nuclei, owing to the well-understood mechanism of electromagnetic interaction.

Despite a long-standing desire to explore exotic features of short-lived unstable nuclei through electron scattering, it has been impeded by the difficulty in preparing thick targets.
We have recently achieved a significant milestone by realizing electron scattering from $^{137}$Cs, which was generated via the photo-fission of uranium and promptly transferred to the SCRIT system for trapping within a short time.
The SCRIT is a novel internal target-forming technique, which allows us to form a stationary target along the electron beam and achieve high luminosity with a small number of target ions.

This experiment serves as a noteworthy emulation of electron scattering from short-lived unstable nuclei produced online, such as $^{132}$Sn in the future.
In this contribution, we will present recent progress and prospects of the SCRIT electron scattering facility.
Additionally, we will discuss several topics that may only be feasible in the future using the SCRIT method.

Speaker: 暁 塚田 (ICR, Kyoto University)

16:30 Noble Gas measurements of nuclear fuel particles from Chernobyl

During the Chernobyl reactor accident on April 26, 1986, radioactivity was in part released in the form of nuclear fuel particles. These so-called “hot particles” have various structures that belong to specific oxidation states of uranium. These oxidation states behave differently in the environment. We obtain individual particles by density separation with a poly tungsten solution. Via radiometric scanning with a Geiger counter we locate the particles. The extraction is performed on tungsten needles with a micromanipulator in a scanning electron microscope (SEM).
The particle surface was analyzed by different nondestructive methods such as SIMS, rL-SNMS and EDX. Gamma measurements and optical analyses in SEM were also performed. The particles are then heated to over 1000°C using a laser beam. This releases the noble gases Kr and Xe from the particles, which can be analyzed using a static mass spectrometer. The age and the neutron flux that the particle has experienced in the reactor can be determined individually for each particle.

Part of this work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-PRES-860948

Speaker: Laura Leifermann (Leibniz Universität Hannover, IRS)

16:50 Development of mid-infrared cavity ring-down spectrometers for radiocarbon/tritium analysis in biomedical tracer and environmental applications

The long-lived radioactive carbon isotope ¹⁴C is widely used as a tracer in environmental and biomedical studies. We have developed a ¹⁴C analytical system based on highly sensitive cavity-enhanced laser absorption spectroscopy, i.e., cavity ring-down spectroscopy (CRDS), and demonstrated ¹⁴C tracer analysis in pharmacokinetics and other areas. In parallel with the development of the ¹⁴C-CRDS, we are focusing on the development of a mid-infrared cavity ring-down spectrometer for tritium analysis. Combined with a robust injection system for small water samples, the analytical performance of the system was investigated using deuterium water analysis. This presentation will overview the CRDS-based ¹⁴C and ³H analytical systems and recent results.

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Acknowledgment: This work was partially supported by JST CREST JPMJCR2104, JSPS KAKENHI: Grant-in-Aid for Transformative Research Areas (B) 22H05023, Japan.

Speaker: Prof. Hideki Tomita (Nagoya University)

17:10 Elemental ratios of spent nuclear fuel by resonance ionization mass spectrometry

In recent years resonance ionization mass spectrometry (RIMS) has shown great progress in analyzing individual micrometer-sized samples. Selective laser ionization of elements resolves most of the abundant isobaric interferences in complex matrices, like spent nuclear fuel. In RIMS, laser light is aimed at a neutral atomic cloud sputtered from the sample surface by a pulsed primary ion source comparable to those found on a commercial static Tof-SIMS instrument. This enables an ultra-trace level analysis free of isobaric interferences with minimal sample consumption.
However, analyses thus far have been limited to measuring isotopic ratios within one element. Ratios of isotopes between elements have been challenging as each element is ionized by separate lasers. Recent improvements to the measurement routine on the Laser Ionization of Neutrals (LION) instrument at the Lawrence Livermore National Laboratory (LLNL, USA) now allows the study of interelemental ratios.
We present the first comprehensive study of elemental ratios from spent nuclear fuel samples by RIMS. This provides increased insight into the sample’s history compared to isotopic ratio measurements alone. For example, the ratios of U/Pu and U/Zr allow a better fuel type determination. If the sample origin is known, elemental ratios allow for studying differences due to fuel type, burnup, and sample location within the reactor in great detail. Particularly, the “edge-effect” (where fission and neutron capture are significantly enhanced at the edge of a fuel pellet relative to the center of the same pellet) can be quantified.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-861692

Speaker: Manuel Raiwa (LLNL)

Tuesday 11 June

09:00 → 10:30 Plenary: 5

Convener: Iain Moore

09:00 Electronic Bridge schemes in $^{229}$Th doped LiCAF

The thorium isotope $^{229}$Th has attracted a lot of interest over the past few decades. This is related to its extremely low-lying first excited state at $\sim$ 8 eV and long radiative lifetime of a few $10^{3} \, \mathrm{s}$ [1]. This makes $^{229}$Th an ideal candidate for a nuclear clock with outstanding properties promising a variety of applications [2].

Large band gap crystals such as CaF$_2$ or LiCaAlF$_6$ (LiCAF) hosting $^{229}$Th have been proposed for the operation of a solid-state nuclear clock.
Among others, these crystals are transparent at the wavelength of the clock transition and a large number of nuclei can be interrogated at the same time [3]. However, DFT simulations of such environments indicate that doping of $^{229}$Th leads to the formation of localized electronic states in the band gap, so-called defect states [4]. These states can be used for effective nuclear excitation via the Electronic Bridge mechanism, as we could show in the case of Th-doped CaF$_2$ crystals [4,5].

Here, we investigate theoretically different laser-assisted Electronic Bridge schemes for $^{229}$Th doped LiCAF crystals and present the corresponding excitation rates. Similar to CaF$_2$ crystals, these schemes can provide, depending on the energetic position of the defect states, orders of magnitude stronger nuclear excitation$/$deexcitation compared to direct photoexcitation with current laser technology. The results are discussed in conjuncture with the design of a solid-state nuclear clock.
[1] S. Kraemer et al., Nature 617, 706-710 (2023).
[2] E. Peik et al., Quantum Sci. Technol. 6, 034002 (2021).
[3] G. A. Kazakov et al., New J. Phys. 14, 083019 (2012).
[4] B. S. Nickerson et al., Phys. Rev. Lett. 125, 032501 (2020).
[5] B. S. Nickerson et al., Phys. Rev. A 103, 053120 (2021).

Speaker: Tobias Kirschbaum (Julius-Maximilians-Universität Würzburg)

PLATAN2024_Kirschbaum.pdf

09:30 Laser ionization of thorium via Rydberg states in hypersonic gas jets

Using efficient laser ionization schemes is a key element when performing atom-at-a-time laser spectroscopy. Auto-ionizing states are often used to enhance ionization due to their higher cross sections compared to excitation directly to the continuum. Nonetheless, for certain elements, either such structures are absent or remain undiscovered [1]. Alternatively, another approach involves exciting the atom to high-lying Rydberg states and subsequently inducing ionization through mechanisms like field ionization, wherein a strong electric field is applied.

We report on the laser excitation of Rydberg states in a hypersonic gas jet. The In-Gas Laser Ionization and Spectroscopy (IGLIS) technique employs a convergent-divergent (de Laval) nozzle to create a cold hypersonic gas jet. Without sacrificing efficiency, the in-gas-jet method allows for sub-GHz spectral resolution of short-lived actinides with low production rates [2]. The new generation of nozzles with a Mach number of $8.5$ enables laser spectroscopy studies of actinides with spectral resolutions around $200$ MHz [3].

Thorium atoms were produced via laser assisted ablation inside an argon filled gas cell and evacuated via the de Laval nozzle. Rydberg states were populated in-gas-jet via laser excitation and subsequently field ionized. The analysis of the found Rydberg states for Th I together with the search for an efficient ionization scheme for Th II allowed for the extraction of an improved value for the ionization potential of both Th I and Th II. Several auto-ionizing states above the second ionization potential were discovered which will be used to improve laser ionization efficiency for in-gas-jet laser spectroscopy studies of $^{229m}$Th$^{+}$. The latter is of interest for the development of a $^{229}$Th based nuclear clock [4].

[1] M. Block et al. Prog. Part Nucl. Phys.,116:103834,2021
[2] R. Ferrer et al. Nature Communications,8:14520,2017
[3] R. Ferrer et al. Physical Review Research, 3:043041:2021
[4] S. Kraemer et al. Nature, 617:706-710,2023

Speaker: Arno Claessens

09:50 Collinear laser spectroscopy of U isotopes at IGISOL

Actinide elements present a rich spectrum of nuclear structure phenomena, and have been the focus of many research programs aimed at developing a detailed picture of this region of the nuclear chart. For example, theoretical models have predicted the emergence of pronounced reflection-asymmetric shapes moving towards more neutron-deficient isotopes[1]. The region also hosts two unique low-lying isomeric states, $^{229}$Th and $^{235}$U, the former of which has great potential to act as a nuclear-based metrology time standard.

Laser spectroscopic techniques act as a bridge between nuclear and atomic physics, providing access to information including the evolution of mean-square charge radii through the measurement of isotopic shifts in atomic transitions, in addition to nuclear magnetic dipole and electric quadrupole moments obtained via the hyperfine structure[2]. In the region of the actinide elements and above, these studies are often limited by the challenges in producing the nuclei of interest.

Within the LISA(Laser Ionization and Spectroscopy of Actinides) framework, a research program aimed towards the study of the nuclear structure of light actinide elements has been implemented at the IGISOL facility, at the University of Jyväskylä. High resolution collinear laser spectroscopy on natural U isotopes has been performed on 10 transitions in the singly charged ion. New information on atomic hyperfine parameters in addition to high precision isotopic shifts has been produced. In parallel, the development of a gas-cell based production method of an isomeric beam of $^{235}$U has been carried out, with the final aim of performing a collinear laser spectroscopy measurement of the low lying 76-eV isomer.

This contribution presents the results of these studies, the upgrades of the light collection region and the the use of ultra-short time bunches to further increase the sensitivity of the technique.
[1]Cao,Y. et al. PRC 102.2 (2020) 024311.
[2]Yang,X. et al. PPNP 129 (2020): 104005.

Speaker: Andrea Raggio (University of Jyväskylä)

main-comp.pdf

10:10 Nuclear octupole shapes in Actinides with Fayans functionals

Static octupole deformation, also called reflection asymmetric by contrast with the quadrupole deformation, displays a profound signature on the observables and systematics of the nuclear ground state $[1]$ and are expected to manifest mostly in the heavier Actinides region of the nuclear chart. Such deformations present a non-negligible impact on the excitation spectra and nuclear properties, for example on the nuclear Schiff moment $[2]$, thus posing important tests for theoretical nuclear structure models.
The typical Skyrme energy density functional of a nuclear density functional theory encompasses many nuclear properties, giving rise to a variety of Skyrme-based EDFs, each adjusted using experimental measurements, and of which results are then compared to nuclear data $[3]$.
In order to further improve accuracy, Fayans EDFs have been recently developed, enriching the current-generation EDFs with the Fayans pairing term $[4]$, and have been successfully tested on various isotopic chains via the comparison with
state-of-the-art charge radii measurements $[5][6][7]$.
Based on earlier theoretical surveys in which some Actinides clusters present significant octupole deformation $[8]$, our work aims to both verify the expected precision of the newly-adjusted Fayans functionals and confirm their stronger octupole preponderance.
As such, we present a first-of-its-kind systematic survey of octupole deformation and associated nuclear properties computed by Fayans EDFs, of which we compared the results to recent studies on pear-shaped nuclei $[9]$. Moreover, these new functionals manifest promising results regarding odd-even effects, namely on radii, within isotopic chains.

P.A.Butler, Proc.R.Soc.A, 476 (2020)
J.Dobaczewski et al., Phys.Rev.Lett., 121, 23 (2018)
J.Bonnard et al., Phys.Lett.B, 843 (2023)
P.G.Reinhard, W.Nazarewicz, Phys.Rev.C, 95, 6 (2017)
A.J.Miller et al., Nat.Phys., 15 (2019)
\'A.Koszor\'us et al., Nat.Phys., 17 (2021)
M.Reponen et al., Nat.Commun., 12, 1 (2021)
S.Ebata and T.Nakatsukasa, Phys.Scripta, 92, 6 (2017)
Y.Cao et al., Phys.Rev.C, 102, 12 (2020)

Speaker: Gauthier Danneaux (Department of Physics, University of Jyväskylä, Jyväskylä, Finland)

Platan 2024 G. Danneaux Slides.pdf

10:30 → 11:00 Coffee

11:00 → 12:30 Plenary: 6

Convener: Ari Jokinen (University of Jyvaskyla (FI))

11:00 Progress at the N=126 factory at ANL

The N=126 factory is a new facility that uses multi-nucleon transfer reactions to create neutron-rich isotopes of the heaviest elements for studies of interest to the formation of the last abundance peak in the r-process. This region of the nuclear chart is difficult to access by standard fragmentation or spallation reactions and as a result has remained mostly unexplored. The nuclei of interest, very neutron-rich isotopes around Z=70-95, will be produced by multi-nucleon exchange of a high intensity 10 MeV/u 136Xe beam on the most neutron-rich stable isotopes of heavy elements such as 198Pt and 238U. This reaction mechanism can transfer a large number of neutrons and create with larger than mb cross-section very neutron-rich isotopes. The reaction mechanism is a nuclear surface process and the reaction products come out at around the grazing angle which makes them very difficult to collect. The N=126 factory circumvents this difficulty by using a unique large high-intensity gas catcher, similar to the one currently in operation at CARIBU, to collect the target-like reaction products and turn them into a low-energy beam that is then mass separated with a medium resolution electromagnetic separator (dM/M ~ 1/1500), followed by an RFQ buncher and an MR-TOF (dM/M ~ 1/100000) system. The extracted radioactive beams are essentially pure and will be available at low-energy for mass measurements with the CPT mass spectrometer, decay study with the X-array, and eventually laser spectroscopy studies. Overall status and commissioning results for the facility, together with the planned physics program, will be presented.

This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357 and used resources of ANL’s ATLAS facility, an Office of Science User Facility.

Speaker: Guy Savard

11:30 In-gas-cell laser ionization spectroscopy of heavy refractory nuclei produced at KISS

We have developed the KEK Isotope Separation System (KISS) [1] at RIKEN to study the nuclear structure of the nuclei in the vicinity of neutron magic number N = 126 and 238U from the astrophysical interest. These neutron-rich nuclei have been produced by using multinucleon transfer (MNT) reactions [2] with the combinations of the low-energy 136Xe/238U beams and the production targets of W, Ir, and Pt. At the KISS facility, these MNT radioisotopes are ionized by applying in-gas-cell laser ionization technique. In the ionization process, we can perform laser ionization spectroscopy of the refractory elements with the atomic number Z = 70-78 such as Hf, Ta, W, Re, Os, Ir, and Pt, which can not be performed in other facilities. Laser spectroscopy is a powerful method to effectively investigate the nuclear structure through the measured magnetic moments and isotope shifts, and the deduced changes in the mean-square charge radii and quadrupole deformation parameters.
We have performed in-gas-cell laser ionization spectroscopy of 199g,199m, 200, 201Pt [3], 196,197,198Ir [4], 194,196Os [5], and 191,192Re produced at KISS. By using multi-reflection time-of-flight mass-spectrograph, we can identify the unstable nuclei from the measured atomic masses and efficiently measure the hyperfine structure, even though for long-lived nuclei, from the counting of the number of laser ionized atoms without detecting decay radiations.
In this conference, we will report the results of laser ionization spectroscopy, and the perspective of future plan at KISS.

References
[1] Y. Hirayama et al., Nucl. Inst. Meth. B353, 4 (2015), and B412, 11 (2017).
[2] Y.X. Watanabe et al., Phys. Rev. Lett. 172503, 1 (2015).
[3] Y. Hirayama et al., Phys. Rev. C 96, 014307 (2017), and 106, 034326 (2022).
[4] M. Mukai et al., Phys. Rev. C 102, 054307 (2020).
[5] H. Choi et al., Phys. Rev. C 102, 034309 (2020).

Speaker: Yoshikazu HIRAYAMA (WNSC, KEK)

PLATAN2024_KEK_Hirayama_web.pdf

11:50 Laser-polarised unstable nuclei at ISOLDE

At the VITO beamline at ISOLDE [1], we use optical pumping with tunable lasers to polarise nuclear spins of different short-lived nuclei. We then use the resulting anisotropic emission of beta radiation in a variety of fields, from nuclear structure, via material science, all the way to biology.
Combining optical pumping with beta-decay detected nuclear resonance (beta-NMR) in liquid samples has allowed us to narrow the linewidth of NMR resonances by two orders of magnitude. Thanks to this achievement we have pushed to ppm levels the accuracy of magnetic moments of short-lived isotopes [1]. We now use this approach to study the distribution of nuclear magnetisation throught measurements of the hyperfine anomaly [2]. Recently, we have also started a programme in decay spectroscopy of laser-polarized beams, in which we study angular correlations between emitted beta particles, gamma-radiation, and neutrons. The aim is to determine spins and parities of excited states in neutron-rich nuclei, especially bet-delayed neutron emitters relevant for the r process nucleosynthesis.
This contribution will present the VITO experimental setup, recent studies with neutron rich potassium isotopes 2,3], and the upcoming measurements of the magnetic moment of $^{11}$Be [4] and of solid-state battery materials with $^8$Li [5].

1. R. Harding et al., Phys. Rev. X 10 (2020) 041061. M Jankowski et al, to be submitted
2. M.L. Bissell et al, in preparation
3. M. Piersa-Silkowska et al., CERN-INTC-2023-026 / INTC-P-662, and M. Piersa-Silkowska et al., in preparation
4. M.L. Bissell et al, CERN-INTC-2023-014 / INTC-P-655
5. G. Rees et al., CERN-INTC-2023-078 / INTC-I-267

Speaker: Magdalena Kowalska (CERN)

12:10 Spectroscopic opportunities for rare isotopes with the MIRACLS technique and laser cooling

The MIRACLS experiment at ISOLDE/CERN combines the usage of ion traps and lasers to probe exotic radioactive nuclides [1]. In order to increase the sensitivity of fluorescence-based collinear laser spectroscopy (CLS), MIRACLS traps ion bunches in a Multi-Reflection Time of Flight (MR-ToF) device. Hence, the ions are probed multiple times instead of just once. This increases the laser-ion interaction time with each revolution in the MR-ToF apparatus, while the high resolution of CLS is retained by using a high-energy MR-ToF.

A successful proof-of-principle experiment with 1.5keV beam energy showed that the MIRACLS technique is working. However, to perform high-resolution CLS a newly built high-energy MIRACLS setup is currently under commissioning, with the goal to measure the charge radii of $^{33,34}$Mg. These observables would deepen our understanding of the $N=20$ island of inversion and act as stringent benchmark for nuclear theory, in particular ab initio methods.

As part of the proof-of-principle experiment, we also performed studies of laser and sympathetic cooling in a Paul trap, normally used for buffer-gas cooling [2]. Even though this trap only has axial laser access, the time spread of $^{24}$Mg ions was drastically reduced by laser cooling. Moreover, we sympathetically cooled $^{16}$O$_2$, $^{39}$K and $^{25,26}$Mg. Backed-up by simulations, we demonstrated the feasibility of laser cooling at radioactive ion beam facilities in a time span of a few 100ms, compatible with short-lived radionuclides.

This oral contribution will introduce the MIRACLS concept, present results from a proof-of-principle experiment, show the new experimental setup and outline the opportunities of ultra-cold radioactive isotopes via laser cooling.

[1] S. Sels et al., Nucl. Instr. Meth. B, 463, 310-314 (2019)
[2] S. Sels, F.M. Maier, et al., Phys. Review Research 4, 033229 (2022)

Speaker: Dr Simon Lechner (CERN)

12:30 → 14:00 Lunch, Student lunches sponsored by VacuumService

Student lunches sponsored by SV Vacuumservice Oy

14:00 → 15:30 Plenary: 7

Convener: Prof. Daniel Rodríguez (Universidad de Granada)

14:00 Laser spectroscopy of the heaviest elements

While nuclear shell effects are responsible for the existence of the heaviest elements, their atomic structure is strongly influenced by relativistic effects that lead to different atomic and chemical properties than their lighter homologs. Here, laser spectroscopy is a powerful tool for revealing fundamental atomic and also nuclear properties, which are reflected as subtle changes in the atomic transitions studied. The general lack of atomic information on the heavy elements, the low production rates and the relatively short half-lives make experimental investigations a challenge and require very sensitive experimental techniques.

Laser spectroscopy of heavy nobelium isotopes (No, $Z$=102) produced in accelerators in atom-at-a-time quantities became accessible through the pioneering experiment with the RAdiation Detected Resonance Ionization Spectroscopy (RADRIS) technique coupled to the SHIP velocity filter at GSI in Darmstadt. With additional developments of the setup, the range of the method was extended to $^{251,255}$No and for the first time also to on-line produced fermium isotopes (Fm, $Z$=100). These online experiments are complemented by off-line laser spectroscopy measurements at the RISIKO mass separator of the University of Mainz on reactor-grown heavy actinides with suitable long lifetimes. Hot cavity laser spectroscopy on radiochemically purified samples enabled the investigation of isotopes of the heavy actinides curium, californium, einsteinium and fermium. These experimental efforts are accompanied by improvements in theoretical atomic calculations, which are essential for determining the properties of the nuclear ground state from the extracted atomic observables of isotopic shifts and hyperfine structure parameters. The combination of results from different fields of research provides an insight into the special nuclear nature of the heaviest elements. The results obtained are discussed with respect to the predictions of nuclear theory and the perspectives for laser spectroscopic investigations in even heavier systems.

Speaker: Sebastian Raeder (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))

14:30 Laser Spectroscopy of Californium-253,254

The 60-day spontaneously fissioning isotope californium-254 is the most neutron-rich known isotope of this element. Due to its anomalously long half-life, it is predicted to have a particularly high impact on the brightness of electromagnetic transients associated with neutron star mergers on the timescale of 10 to 250 days [Zhu et al., AJL 863, L23 (2018)]. Experimental information on Cf-254 is scarce, owing to limited production capabilities in the laboratory. We have performed optical spectroscopy on this and other neutron-rich isotopes in this part of the nuclear chart. For this, targets of heavy Cm isotopes were neutron-irradiated at the High Flux Isotope Reactor, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA, to breed transcurium isotopes including Cf-252 and Es-253,254. A chemical separation performed at ORNL’s Radiochemical Engineering Development Center yielded the Es fraction, which also contained some Cf-252. This sample was shipped to Johannes Gutenberg University Mainz (JGU), Mainz, Germany, via Florida State University (FSU), Tallahassee, FL, USA, and then sent to Institut Laue-Langevin (ILL), Grenoble, France, for a second irradiation with thermal neutrons to produce more neutron-rich isotopes including the 40-d isotope Es-255, which continuously feeds the 20-h Fm-255, as well as 18-d Cf-253 and 60-d Cf-254. Laser resonance ionization spectroscopic studies were performed at the RISIKO mass separator at JGU. In californium, the hyperfine structure of the 420 nm ground state transition in Cf-253 and the isotope shift of Cf-254 in the 417 nm and 420 nm ground-state transitions were determined with high resolution down to 140 MHz FWHM by using the Perpendicularly-Illuminated Laser Ion Source and Trap (PI-LIST). These data provide a basis for a King plot analysis of the optical spectrum of Cf-254 based on known results in lighter californium isotopes, where substantially more data are available.

Speaker: Sebastian Berndt (Johannes Gutenberg Universität Mainz, 55099 Mainz, Germany)

14:50 Laser spectroscopy of fermium-255 at the RISIKO mass separator facility

Laser spectroscopy provides information about the fundamental properties of atomic and nuclear structure of the constituents of matter. Measurements are of general importance all along the nuclear chart but are specifically thrilling for the heavy actinides and superheavy elements, where data is sparse and theoretical descriptions can be tested. For an extensive measurement campaign at the RISIKO mass separator facility at the Institute of Physics at Johannes Gutenberg University Mainz, samples of the anthropogenic isotope ${}^{255}$Fm (Z=100) with $10^8$ to $10^9$ atoms each were made available. They were used for studies on the atomic level structure, ionization potential, and hyperfine structure in fermium. The samples initially originate from a ${}^{254}$Es sample that was produced at the HIFR high flux research reactor at the Oak Ridge National Laboratory, Oak Ridge (USA) by neutron breeding. The sample was subsequently re-irradiated at the Institut Laue-Langevin reactor in Grenoble (F) to produce suitable amounts of ${}^{255}$Es (half-life: 39.8 d), which decays to ${}^{255}$Fm (20.07 h) via $\beta^-$ decay, and chemically separated after appropiate ingrowth. This presentation will focus on the atomic structure studies of ${}^{255}$Fm, discussing new three-step laser ionization schemes. Rydberg level convergences were studied and the accuracy of the ionization level was improved.

Speaker: Mr Matou Stemmler (Johannes Gutenberg Universität Mainz, 55099 Mainz, Germany)

Presentation Matou Stemmler Matou Stemmler PLATAN.pdf

15:10 Fingerprinting heavy elements via Laser Resonance Chromatography: First demonstrations on Lu$^+$

Atoms of different elements possess distinct spectra which serve as their fingerprints. Beyond providing information about the internal atomic and nuclear structure, knowledge of their spectra has allowed their identification in extragalactic stars and even neutron star mergers. However, very little is known about elements beyond fermium ($_{100}$Fm), which can only be synthesized in trace amounts in nuclear fusion-evaporation reactions. With scarce production yields below one atom per second, traditional fluorescence methods are insufficient for the spectroscopy of these elements. Given the need for alternatives, a new method called Laser Resonance Chromatography (LRC) was conceived, which doesn’t rely on detection of fluorescence. In LRC, after resonant excitation, ions in different electronic states are separated via their distinct mobilities in buffer gas. Here, with an experimental setup we recently commissioned, we present results from the first demonstration done on lutetium ($_{71}$Lu). We studied a ground-state transition in Lu$^+$ ions, and the hyperfine structure constants and isotope shifts that we derived for it are in excellent agreement with values known from laser-induced fluorescence. With lutetium being an electronic homologue of the element lawrencium ($_{103}$Lr) for which not even a single atomic transition has been reported till date, this concretely demonstrates the viability of our method and opens a new avenue for laser spectroscopy of the heaviest elements.

Speaker: Aayush Arya (Helmholtz-Institut-Mainz / JGU Mainz)

15:30 → 16:00 Coffee

16:00 → 17:30 Plenary: 8

Convener: Magdalena Kowalska (CERN)

16:00 Plans for laser spectroscopy at the proton drip line

At the edges of the nuclear landscape, a rare form of radioactive decay occurs where the nucleus emits a proton. But what is the shape of the nucleus in the moments before it emits a proton? And how does the shape of the nucleus change when the proton becomes unbound? Studying nuclei at the proton drip line with laser spectroscopy may help to provide insights into these questions.

Laser spectroscopy measures the hyperfine structure of atoms, an atomic fingerprint that allows nuclear properties (e.g. spin, electromagnetic moments and charge radii) to be measured. For example, the charge radius tells us about the proton distribution in the nucleus i.e. its shape. By measuring nuclei across the proton-drip line (beyond which proton decay occurs), we hope to gain a unique insight into how a single proton can influence the behaviour of the whole nucleus.

In this talk, I will introduce the concept of proton emission from a nucleus, describe how laser spectroscopy can measure fundamental nuclear properties and outline my plans for measuring the shape of nuclei at the proton drip line. I will outline my plans to measure proton-rich nuclei at ISOLDE, utilising the CRIS experiment and the newly developed PI-LIST setup, as well as future plans to continue studies at the new RISE setup, recently integrated into the BECOLA facility at FRIB.

Speaker: Kara Marie Lynch (University of Manchester (GB))

16:30 Implantation of pure Fe-55 into microcalorimeters for activity standardization measurements

Radionuclide metrology techniques, as currently used for activity standardization, show a large variety of measurement uncertainties – from permille accuracy, e.g., for the α-decaying isotope Am-241 (T1/2 = 432 a) up to few percent for Fe-55 (T1/2 = 2.73 a), which decays by electron capture. To reduce such uncertainties, a new standardization technique using direct ion beam implantation of the pure radionuclide into metallic microcalorimeters (MMCs) is explored within the European project PrimA-LTD. The intrinsically high energy resolution of such devices additionally allows for determination of electron capture probabilities with unprecedented accuracy, in this way enables the improvement of theoretical models and correspondingly has a broad impact on radionuclide metrology, nuclear power industry, nuclear medicine and radiopharmacy.

The implantation of 5 Bq of Fe-55 into each minuscule absorber, sized 0.14 x 0.14 mm2, of such MMC detectors was performed at the RISIKO mass separator at Mainz university using resonance ionization mass separation and specific focalization and automated pointing. The technique was chosen due to its outstanding element selectivity and overall implantation efficiency guaranteeing the required implantation purity. A novel two-step ionization scheme for iron was identified and characterized in stable Fe-56, implying efficient second and third harmonic generation of the Ti:Sa laser radiation used at RISIKO. One of different strong auto-ionizing states was used for implantation of the Fe-55. In Fe-56, the analysis of a long series of Rydberg states allows to verify the ionization potential and extend the existing data on even parity Rydberg states in Fe. The spectroscopic results will be discussed as prerequisite for the implantation process.

The project has received funding from the EMPIR program 20FUN04 PrimA-LTD from the European Union's Horizon 2020 research and innovation program.

Speaker: Thorben Niemeyer (Johannes Gutenberg University Mainz)

16:50 Measurement of the shift in the electron affinities of tin isotopes at DESIREE

The electron affinity (EA) is the energy released when an additional electron is bound to a neutral atom, creating a negative ion. Due to a lack of long-range Coulomb attraction, the EA is dominated by electron-electron interactions, making negative ions excellent systems to probe these effects. A particular example is the determination of the specific mass shift, which is of importance when extracting nuclear charge radii from laser-spectroscopy experiments. However, only very few isotope shifts of the EA have been measured to date.
Berzinsh et al. [1] investigated the isotope shift of the EA of the two stable chlorine isotopes, 35Cl and 37Cl both experimentally and theoretically. A discrepancy in their experimental and theoretical results was then solved by Carette and Goodefroid in 2013, increasing the precision of their calculations beyond the uncertainty of the experimental value.
Consequently, a study of the isotope shift of a large mass range of chlorine isotopes was proposed at the radioactive ion beam facility CERN-ISOLDE and performed in 2024 using the GANDALPH spectrometer [3], which was successfully used to determine EAs of radioisotopes previously [3,4].
Here, we will present the results of this measurement campaign and give an outlook on future experiments using the charge exchange process to produce negative ions.

References:
[1] Berzinsh et al. Phys. Rev. A 51, (1995) 231
[2] Carette and Godefroid, J. Phys. B 46 (2013)
[3] Rothe et al., J. Phys. G (2017)
[4] D. Leimbach et al. Nat. Comm 11, 3824 (2020)

Speaker: David Leimbach (Gothenburg University (SE))

17:30 → 20:00 Poster session

Wednesday 12 June

09:00 → 10:30 Plenary: 9

Convener: Prof. Thomas Elias Cocolios (KU Leuven - IKS)

09:00 Laser Probing of Rare Isotopes: Krypton, Radium, and Beyond

Laser excitation and manipulation techniques offer unique control of an atom’s external and internal degrees of freedom. The species of interest can be selectively captured, cooled, and observed with high signal-to-noise ratio down to the single atom level. Moreover, the atom’s electronic and magnetic state populations can be precisely manipulated and interrogated. Applied in nuclear physics, these techniques are ideal for precision measurements in the fields of fundamental interactions and symmetries, nuclear structure studies, and isotopic trace analysis.

In this talk, I will concentrate on recent advances in Atom Trap Trace Analysis (ATTA) as a highly selective and sensitive atom counting technique. It has now been established as a routine tool in the geosciences for radiokrypton dating of ancient groundwater and glacial ice samples on timescales of a few ten thousand to a couple million years. The isotope of interest here is the cosmogenic krypton-81 with its half-life of 230,000 years and its isotopic abundance at the parts-per-trillion level in the atmosphere. I will introduce the basic principles and recent progress of the ATTA technique and present selected applications with their impact on understanding groundwater resources and paleoclimatic changes.

I will also present short updates on our experimental effort to measure the permanent electric dipole moment of Radium-225 via laser cooling and trapping, and on a recent milestone in performing collinear laser spectroscopy of rare nuclei at Argonne’s ATLAS facility.

This work is in part supported by the U.S. DOE, Office of Science, Office of Nuclear Physics, under contract DE-AC02-06CH11357.

Speaker: Peter Mueller (Argonne National Laboratory)

PMueller Platan 2024 fnl.pptx

09:30 Collinear Laser Spectroscopy on Neutron-Deficient Al Isotopes at RISE/ BECOLA

At the BEam COoling LAser spectroscopy (BECOLA) facility at the Facility for Rare Isotope Beams (FRIB), a Resonance Ionization Spectroscopy Experiment (RISE) instrument has been newly commissioned. This addition to the BECOLA facility will allow for laser spectroscopy to be conducted through both collinear fluorescence and resonant ionization methods back to back in the same beamline. The details of the commissioning will be discussed, including offline $^{27}$Al measurements of hyperfine coefficients on multiple transitions taken in preparation for an online experiment at FRIB. The debated proton-halo structure in $^{22, 23}$Al will be directly addressed by determining the charge radii and electromagnetic moments through the isotope shift and hyperfine structure. A large reaction cross section [1] and a large isospin asymmetry in the mass A = 22 system [2] suggest proton halo structures in $^{23}$Al and $^{22}$Al, respectively. However, the last proton presumably occupies the $d_{5/2}$ orbital in the ground state, making the proton halo structures’ existence not decisive. The first online results obtained with RISE from the experiment scheduled for May 2024 will be discussed.

[1] X. Z. Cai et al., PRC 65, 024610 (2002).
[2] J. Lee et al., PRL 125, 192503 (2020).

This work is supported in part by NSF grant PHY-21-11185 and DOE awards DE-SC0000661, DE-SC0021176, and DE-SC0021179.

Speaker: Brooke Rickey (FRIB at MSU)

Rickey_PLATAN_2024.pdf

09:50 Collinear laser spectroscopy in neutron-rich Ru

The region of refractory metals below tin exhibits a diverse spectrum of nuclear phenomena, i.e., strong deformations and shape coexistence. Particularly, in the neutron-rich Ru isotopes, there are hints for triaxial ground state deformations. To investigate nuclear ground-state properties of short-lived isotopes with collinear laser spectroscopy, a new collinear setup, ATLANTIS – the Argonne Tandem hall LAser beamliNe for aTom and Ion Spectroscopy– was installed at the low-energy branch of CARIBU at Argonne National laboratory. There, the CARIBU californium-252 fission source can uniquely produce sufficiently intense low-energy ion beams of neutron-rich isotopes in this part of the nuclear chart.

Laser spectroscopy was successfully performed in $^{96,98-102,104,106-114}$Ru and charge radii as well as electromagnetic moments were extracted. In this talk, the results will be presented and compared with the latest Brussels models BSkG1, BSkG2 and BSkG3 which are energy density functional calculations of the Skyrme type that include triaxiality. Furthermore, an outlook of future laser spectroscopy endeavors at Argonne National Laboratory will be given.

This work was supported by DFG – Project-Id 279384907-SFB 1245, BMBF 05P19RDFN1 and NSF Grant No. PHY-21-11185, and by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357, with resources of ANL’s ATLAS facility, an Office of Science User Facility.

Speaker: Kristian Koenig (Technische Universitaet Darmstadt (DE))

10:10 On the use of charge distribution in nuclei to constrain effective interactions

The key ingredient for mean-field calculations in nuclear structure is the
effective interaction which models the strong force in the nuclear medium.
Such interactions usually depend on a set of parameters fitted to
properties nuclei and infinite nuclear matter.

These interactions can suffer several limitations and problems. For
example, since they are usually adjusted on properties of observed nuclei
close to the valley of stability, their predictive power for exotic and super-heavy nuclei may be questionable. Furthermore, unphysical finite-size instabilities can sometimes appear when these interactions are used to calculate properties of nuclei which have not been considered to constrain their parameters. These unwanted features then make them of very limited interest. These instabilities can appear in various channels and therefore have scalar, vector, isoscalar or isovector characters.

It was shown that the formalism of the linear response in infinite-nuclear
matter can be used to avoid such instabilities for the construction of
zero-range interaction (of Skyrme type). Although such a formalism
was also developed for finite-range interactions (Gogny type),
the calculations for the linear response are much more time-consuming and
can hardly be incorporated in the procedure used to fit their parameters.

I will discuss how the scalar-isovector instabilities are related to the
distributions of protons and neutrons in nuclei and how, in turn,
information on charge density distributions can be used to
prevent these instabilities. Beside the avoidance of instabilities,
information about the charge distribution can lead to a better balance
between the different contributions to the binding energy of nuclei and
their evolution with mass and asymmetry. I will show that the use of
constraints on charge distributions from a set of chosen nuclei can be
used to avoid the appearance of scalar-isovector instabilities and discuss
how this could improve the predictive power of the mean-field
calculations.

Speaker: Karim BENNACEUR

presentation.pdf

10:30 → 11:00 Coffee

11:00 → 12:30 Plenary: 10

Convener: Jens Lassen

11:00 Radioactive molecule spectroscopy towards searches for BSM physics

Molecules that contain heavy and radioactive nuclei can be highly sensitive to a number of nuclear observables of interest, such as the typically studied nuclear magnetic dipole and electric quadrupole moments, but also symmetry-violating hadronic, leptonic, and nuclear moments.

Precision experiments based on heavy and polar radioactive molecules have been proposed as being potentially the most sensitive probes to pin down the level of time-reversal violation in the fundamental forces. Significant technical developments are necessary to bridge the gap between radionuclide production and the techniques that have been developed for high-precision experiments with stable molecules, however. Therefore, global efforts are invested in enabling precision searches for beyond-the-Standard-Model physics with radioactive molecules, along multiple technical directions.

In this talk, the opportunities for fundamental and nuclear physics research with radioactive molecules will be overviewed, followed by a summary of the experimental techniques that have been developed for the type of experiments that radioactive molecules are envisioned for. A summary of recent activities on the production and study of radioactive molecules at CERN-ISOLDE will follow.

Speaker: Michail Athanasakis-Kaklamanakis (Imperial College London)

11:30 High accuracy predictions of properties of heavy atoms and molecules and evaluation of uncertainties.

Theory can provide important support at all the stages of spectroscopic experiments, from planning the measurements, through extracting the properties of interest from the data, and to the interpretation of the results and their comparison to theoretically predicted values. To be reliable and useful in experimental context, theoretical predictions should be based on high accuracy calculations. Such calculations must include both relativistic effects and electron correlation on the highest possible level.

Relativistic coupled cluster is considered one of the most powerful methods for accurate calculations of properties of heavy many-electron systems. This approach can be used to obtain ionization potentials, electron affinities, excitation energies, hyperfine structure parameters, and other atomic properties, and a variety of molecular properties. It has been shown to be extremely reliable and to have very strong predictive power. Recently, we have developed a scheme that allows us to use extensive computational investigations to assign uncertainties on the theoretical predictions [1], facilitating the use of these predictions in experimental context.

A brief introduction to the relativistic coupled cluster method will be provided and the new development for estimation of uncertainties will be presented. The talk will focus on recent successful applications of the coupled cluster approach to atomic and molecular properties, in particular in connection to recent and planned experiments [2-3 and yet unpublished work].

[1] D. Leimbach, J. Karls, Y. Guo, R. Ahmed, et al,
The electron affinity of astatine
Nature Comm. 11, 3824 (2020)

[2] A. A. Kyuberis, L. F. Pašteka, E. Eliav, H. A. Perrett, A. Sunaga, S. M. Udrescu, S. G. Wilkins, R. F. Garcia Ruiz, and A. Borschevsky
Theoretical determination of the ionization potentials of CaF, SrF, and BaF
Phys. Rev. A 109, 022813 (2024)

[3] K. König, J. C. Berengut, A. Borschevsky, et al.
Nuclear charge radii of silicon isotopes
https://arxiv.org/abs/2309.02037

Speaker: Anastasia Borschevsky

11:50 Radioactive molecular ion beams at CERN-ISOLDE

The ISOLDE facility at CERN provides radioactive ion beams of nuclides produced in reactions between 1.4-GeV protons and thick targets using the Isotope Separation On-Line (ISOL) technique. The formation of volatile molecules has been used as a method to deliver beams of otherwise non-volatile release-limited elements [1-5]. Molecular sideband extraction is also used to improve beam purity. The availability of molecular beams additionally provides opportunities for fundamental physics studies [6-11].

We present our work on molecular ion beam production at CERN-ISOLDE using actinide targets and Forced Electron Beam Induced Arc Discharge (FEBIAD)-type ion sources [12]. Beam composition studies are presented using: the ISOLTRAP Multi-Reflection Time-of-Flight Mass Spectrometer (MR-ToF MS) [13], online γ-ray spectroscopy at the ISOLDE tape station [14,15], and off-line $\alpha$- and γ-ray spectrometry of ion-implanted samples.

References

[1] R. Eder et al., NIMB 62, 535 (1992)
[2] R. Kirchner, NIMB 126, 135 (1997)
[3] H. Frånberg et al., Rev. Sci. Inst. 77, 03A708 (2006)
[4] J. Ballof et al., Eur. Phys. J. A 55, 65 (2019)
[5] U. Köster et al., Eur. Phys. J. Special Topics 150, 293 (2007)
[6] G. Arrowsmith-Kron et al., arXiv, DOI 10.48550/arXiv.2302.02165 (2023)
[7] T. A. Isaev et al, Phys. Rev. A, 82, 052521 (2010)
[8] T. A. Isaev et al., arXiv, DOI 10.48550/arXiv.1310.1511 (2013)
[9] M. Safronova et al., Rev. Mod. Phys. 90, 025008 (2018)
[10] N. Hutzler et al., arXiv, DOI 10.48550/ARXIV.2010.08709 (2020)
[11] R. Garcia-Ruiz et al., Nature 581, 396 (2020)
[12] L. Penescu et al., Rev. Sci. Inst. 81, 02A906 (2010)
[13] R. N. Wolf et al., Int. J. Mass Spec. 123, 349 (2013)
[14] S. Stegemann et al., NIMB. Conf. Proc. EMIS XIX (2022)
[15] R. Catherall et al., J. Phys. G : Nucl. Part. Phys., 44, 094002 (2017)

Speaker: Mia Au

12:10 Ultra-trace analysis of radionuclides with laser ionization mass spectrometry

Resonant laser secondary neutral mass spectrometry (rL-SNMS) combines the spatial resolution traditional ToF-SIMS with the elemental selectivity of resonant laser ionisation. This quasi non-destructive method is an ideal choice for the analyses of micron sized fragments of nuclear fuel, so called “hot particles” from the Chornobyl exclusion zone [1]. With this method actinides in single radioactive can be detected, down to E7 atoms of a single isotope [2]. The relative 238Pu content of the particles can be determined by suppressing the dominant 238U in spent fuel. The isotopic fingerprint of these particles allows to links them to the nuclear accident as well as identifying particles with unusual isotope ratios. The current capabilities of the RIMS-system are presented in this talk, with an outlook on further developments of the method and application to ultra-trace analysis.

[1] DOI:10.1039/9781837670758-00001
[2] DOI:10.1126/sciabv.abj1175

Speaker: Paul Hanemann

12:30 → 14:00 Lunch

14:00 → 16:00 Lab tour (optional)

16:00 → 19:00 Free time / Excurions

19:00 → 21:00 IAC dinner

Thursday 13 June

09:00 → 10:30 Plenary: 11

Convener: Piet Van Duppen (KU Leuven (BE))

09:00 The current status of S3LEB at GANIL

S3LEB (Super Separator Spectrometer-Low Energy Branch) is a low energy radioactive ion beam facility, which will be employed for the study of exotic nuclei, under commissioning as a part of GANIL-SPIRAL2 facility [1]. High intensity primary beams, delivered by the superconducting LINAC of the SPIRAL2 facility, will allow for increased production rate for nuclear fusion evaporation reaction, thus will facilitate exploration of some critical areas of the nuclide chart with low production cross section and shorter lifetime. The produced ions will be separated by the recoil separator S3 and will be send to the S3LEB facility at the focal plane of S3 [2].
S3LEB is a gas cell setup followed by radiofrequency quadrupole units, which allows selective ionization of radioactive ions of interest as well as efficient transmission of the ions to an MR-TOF (Multi-Reflection Time of Flight separator) for further beam purification and detection. The ions thermalized and neutralized inside the buffer gas cell are selectively laser ionized either inside the gas cell or in a hypersonic gas jet environment created after the gas cell using a De-Laval nozzle. The S3LEB set up has been commissioned off-line [3,4] and is now being installed at the focal plane of S3, in preparation for on-line commissioning.
Here we present the status of the set up as well as the recent off-line measurements, including in-gas-cell and in-gas jet laser spectroscopy of erbium isotopes in combination with trapping, selection and mass measurement with the multi-reflection time-of-flight mass spectrometer PILGRIM.
Finally, the road map to online commissioning will be presented.
[1] A.K.Orduz, 31st Linear Accelerator Conference, Aug 2022, Liverpool, UK
[2] F. Déchery et al., Eur. Phys. J. A 51, 66 (2015)
[3] J. Romans, et al., Nucl. Instrum. Meth. B 536, 72 (2023)
[4] A. Ajayakumar, et al., NIM B 539, 102 (2023)

Speaker: Dr Nathalie LECESNE (GANIL)

09:30 Mass measurements of exotic nuclides in the vicinity of $^{100}$Sn and their implications to nuclear structure

The heavy $N=Z$ nuclei and the nuclei in their vicinity are highly interesting to study; they can provide important insights about nuclear structure, symmetries and interactions and have a high impact in modelling nuclear astrophysics processes ($rp$-process, $\nu p$-process). A few examples of the striking phenomena are the formation of high-spin isomeric states, the direct and/or $\beta$-delayed proton emission from ground or excited states and the strong resonances in Gamow-Teller transitions close to the proton dripline. The FRS Ion Catcher (FRS-IC) experiment at the in-flight fragment separator FRS at GSI enables highly accurate direct mass measurements ($\delta m/m \sim 10^{-8}$) with thermalized projectile and fission fragments by combining a cryogenic stopping cell and a multiple-reflection time-of-flight mass spectrometer. Supported by mass measurements at the FRS-IC within FAIR Phase-0, including the first direct mass measurement of $^{98}$Cd, the evolution of Gamow-Teller transition strengths (B(GT)) for even-even $N=50$ and $N=52$ isotones was studied [1]. Comparing experimental and theoretical B(GT) values sheds more light on the controversy around the mass of $^{100}$Sn [2,3,4]. Additionally, the excitation energy of the long-lived isomer in $^{94}$Rh was determined for the first time; comparing the value of which with shell model calculations allows to understand the level ordering and spin-parity assignments of the observed states [1]. The mass of $^{93}$Pd was measured directly for the first time, reducing the mass uncertainty by an order of magnitude. This helps to further unravel the riddle surrounding the exotic decay modes of the $(21^+)$ high-spin isomer of $^{94}$Ag, the investigations of which were summarized in Ref.[5,6].

[1] A. Mollaebrahimi et al., Phys.Lett.B 839,137833(2023).
[2] C.B. Hinke et al., Nature 486(2012)341.
[3] D. Lubos et al., Phys.Rev.Lett. 122(2019)222502.
[4] M. Mougeot et al., Nat.Phys. 17,1099-1103(2021).
[5] A. Kankainen et al., Eur.Phys.J.A 48,49(2012).
[6] E. Roeckl and I. Mukha, Int.J.Mass.Spectrom. 349-350,47(2013).

Speaker: Gabriella Kripkó-Koncz (II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen, Germany)

PLATAN2024_93Pd98Cd_GKK_final_uploaded.pdf

09:50 MR-ToF mass measurements of the isomeric states in 94Ag produced with a hot cavity at IGISOL

The N=Z nucleus 94Ag has intrigued physicists for decades thanks to its unique decay modes, long-living isomeric states, and structure. Most notably, the existence of an elusive two-proton decay channel in its spin 21+ isomeric state has been a subject of debate since its first reports in 2006 [1]. Subsequent investigations of 94Ag have not found evidence of two-proton emission, although other decay channels, such as the one-proton emission, have been reported [2]. This has raised interest to study further the feasibility of the two-proton emission of 94Ag.

Comparing spectroscopic data with atomic mass measurements points to a discrepancy of 1.4 MeV in the 21+ state energy, suggesting that the two-proton decay is energetically forbidden [3]. A direct mass measurement of the 21+ state is required to impose constraints to the possible two-proton emission channels.

The masses of the isomeric states of 94Ag have been measured for the first time, employing a combination of a hot cavity catcher laser ion source [4] and a Multi-Reflection Time-of-Flight Mass-Separator (MR-ToF-MS) at the Ion Guide Isotope Separator On-Line (IGISOL) - facility. In this contribution I will present an overview of the experiment and the masses of the 94Ag states.

References
[1] I. Mukha et al. Proton–proton correlations observed in two-proton radioactivity of 94Ag. Nature, 439:298–302, 2006

[2] J. Cerny, et al. Reinvestigation of the direct two-proton decay of the long-lived isomer 94Agm [0.4 s, 6.7 MeV, (21+)]. Physical Review Letters, 103:152502, 2009.

[3] A. Kankainen, et al. Mass measurements and implications for the energy of the high-spin isomer in 94Ag. Physical Review Letters, 101:142503, 2008.

[4] M. Reponen et al. An inductively heated hot cavity catcher laser ion source. Review of Scientific Instruments 86:123501, 2015.

Speaker: Ville Virtanen (University of Jyvaskyla (FI))

10:10 Optical spectroscopy of the silver isotopic chain

How does the size and deformation of the silver nucleus evolve as a function of neutron number as one moves between two exotic neutron shell closures, N=50 and N=82, and can modern nuclear theoretical methods accurately predict the trends? To address this question, experiments in recent years have been performed at the IGISOL facility using collinear laser spectroscopy [1] and in-source spectroscopy [2], while at the ISOLDE facility, CERN, the CRIS experiment was used to provide complementary information and to extend the study to additional isotopes on either side of the valley of stability.

In addition to the charge radius, magnetic dipole moments provide sensitive information on the purity of the nuclear wavefunction, serving as an additional stringent test for theoretical calculations. In a wider perspective, with atomic number Z = 47, the silver isotopes are located between the magic (Z = 50) tin isotopes and the strongly-deformed region around and below Z = 45.

This contribution will provide a comprehensive picture of the evolution of deformation in this region of the nuclear chart by presenting the evolution of the nuclear charge radius and the nuclear electromagnetic dipole and quadrupole moments of exotic silver isotopes. A summary of the measurements using the different techniques will be highlighted.

[1] R.P. de Groote et al., Phys. Lett. B 848 (2024) 138352.
[2] M. Reponen et al., Nature Comm. 12 (2021) 4596.

Speaker: Sonja Kujanpää (University of Jyväskylä)

10:30 → 11:00 Coffee

11:00 → 12:30 Plenary: 12

Convener: Anu Kankainen (University of Jyväskylä)

11:00 In search of increasingly exotic nuclides at TITAN

As nuclides become increasingly exotic, production yields fall off; contamination increases; and, often the half lives drop. To meet these challenges, developments at the TITAN-TRIUMF facility are continually underway. Its Multi-Reflection Time-Of-Flight (MR-TOF) mass separator has become the preferred tool in probing the limits of radioactive-ion-beam production at TRIUMF via high-precision mass determinations. These measurements are essential for studying evolving nuclear structure as well as for investigating the r- and rp-process in nucleosynthesis. I will present recent results from the MR-TOF and TITAN at large.

Speaker: Anna Kwiatkowski

11:30 Recent mass measurements at ISOLTRAP

High-precision mass measurements of radioactive ions are used to determine nuclear binding energies, which reflect all forces acting in the nucleus and are used to study among others nuclear structure, nuclear astrophysics, and weak interaction.
For this, the ISOLTRAP mass spectrometer at ISOLDE/CERN [1] uses various ion traps, including a tandem Penning-trap system and a multi-reflection time-of-flight mass spectrometer (MR-ToF MS), where the latter is suitable of both mass separation and fast, precise mass measurements.

In this contribution, the first direct mass measurements of neutron-deficient $^{97}\text{Cd}$ and the excitation energy of the $^{97\text{n}}\text{Cd}$ high-lying isomer along with a precise measurement of $^{98}\text{Cd}$ in the immediate vicinity of self-conjugate doubly magic $^{100}\text{Sn}$ ($N=Z=50$) will be presented together with measurements of neutron-rich $^{209,210}\text{Hg}$.
Additionally, the current setup of the ISOLTRAP experiment is introduced together with the future re-bunching system using a new Mini-RFQ behind the MR-ToF MS to enable measurements of extremely isobaric contaminated beams.

[1] D. Lunney et al., J. Phys. G: Nucl. Part. Phys. 44 (2017) 064008

Speaker: Daniel Lange (Max Planck Society (DE))

11:50 High-precision Penning-trap mass measurements of heavy and superheavy elements with SHIPTRAP

Speculation about the existence of elements heavier than uranium started in the late 19^th century [1]. Thanks to an increased understanding of nuclear structure and decades of developments, transuranic and eventually superheavy elements were discovered [2]. The latter owe their existence to nuclear shell effects, which enhance their stability [3]. The strength of these effects can be quantified through direct mass measurements performed with Penning traps [4], providing invaluable information on the nuclear shell evolution. Furthermore, the excitation energies of low-lying, long-lived metastable nuclear states, common in the heavy nuclei, can be obtained from the directly measured masses, complementing decay spectroscopy studies and providing further information.

The goal of the SHIPTRAP experiment is to study heavy and superheavy nuclei produced via fusion-evaporation reactions at rates well below one particle per hour. Nuclei produced at such low rates are accessible thanks to the implementation of a cryogenic buffer-gas stopping cell [5] and the development of the Phase-Imaging Ion-Cyclotron-Resonance technique [6]. These enabled the study of more exotic nuclei [7]. In this contribution, the latest results, obtained as part of the FAIR phase-0 campaign at GSI, will be presented. These comprise measurements on the ground‑state masses and isomeric‑state‑energy measurements of nuclides from ¹⁹⁶Bi to ²⁵⁷Rf.

[1] H. Kragh, Eur. Phys. J. H 38 411-431 (2013)
[2] S. Hofmann and G. Münzenberg, Rev. Mod. Phys. 72, 733 (2000)
[3] S.A. Giuliani et al, Rev. Mod. Phys. 91 011001 (2019)
[4] M. Block, Nucl. Phys. A 944 471-491 (2015)
[5] O. Kaleja et al, Nucl. Instrum. Methods Phys. Res. B 463 280-285 (2020)
[6] S. Eliseev et al, Appl. Phys. B 114 107–128 (2014)
[7] O. Kaleja et al, Phys. Rev. C 106 054325 (2022)

Speaker: Dr Manuel J. Gutiérrez (University of Greifswald, Germany / GSI Darmstadt, Germany / Helmholtz Institut Mainz, Germany)

12:10 Penning-trap eigenfrequency measurement using single laser-cooled ions

A new method for the determination of the eigenfrequencies of laser-cooled ions in a Penning trap has been recently demonstrated. It relies on the measurement of the ion’s motional amplitude using the scattered photons when an internal optical electric dipole transition is addressed by lasers [1]. Compared to other techniques, it is universal regarding the mass-to-charge ratio, it is non-destructive, and allows the observation of motional amplitudes of only a few micrometers, which drastically reduces the systematic uncertainties.
In this contribution, we will present the measurement of the cyclotron-frequency ratios of several calcium isotopes ($^{42,44,48}$Ca$^+$ vs $^{40}$Ca$^+$) using this optical detection method [2]. Single ions are laser-cooled to temperatures in the order of millikelvin [3] and subsequently probed by an oscillating electric field close to one of its eigenfrequencies. The motional amplitude is readout using photon-counting and photon-imaging units while re-cooling the system to the Doppler limit after excitation.
The optical method has also been proved with two-ion Coulomb crystals, yielding the first measurements of the six eigenfrequencies of a balanced ($^{40}$Ca$^+$ - $^{40}$Ca$^+$) and unbalanced ($^{42}$Ca$^+$ - $^{40}$Ca$^+$) crystal, previously studied theoretically in Ref. [4]. The uncertainty from these measurements and the prospects for improvement by accessing the quantum regime will be briefly discussed [5]. We will also present the status of the recent upgrade of our Penning-trap experiment after the installation of a new cryogen-free superconducting magnet.

[1] D. Rodríguez, Appl Phys B 107, 1031–1042 (2012).
[2] J. Berrocal et al., Phys. Rev. Research 6, L012001 (2024).
[3] J. Berrocal et al., Phys. Rev. A 105, 052603 (2022).
[4] M. J. Gutiérrez et al., Phys. Rev. A 100, 063415 (2019).
[5] J. Cerrillo and D. Rodríguez, EPL- Perspective 134, 38001 (2021).

Speaker: Dr Joaquín Berrocal (Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada)

12:30 → 14:00 Lunch, Student lunches sponsored by HÜBNER Photonics

Student lunches sponsored by HÜBNER Photonics GmbH

14:00 → 15:10 Plenary: 13

Convener: Klaus Wendt

14:00 LEMING: Towards measuring the gravitational acceleration g of Muonium

Muonium (Mu = $\mu^+$ + $e^−$) is a purely leptonic, two-body exotic atom amenable for precision measurements of fundamental constants ($m_\mu$, $\mu_\mu$) and tests of bound state QED. Mu also offers the possibility to directly test the coupling of gravity to second generation elementary (anti)leptons, a system where there are no contributions to the mass by the strong interaction. Hence, such measurements are complementary to the new results of the ALPHA collaboration [1].

The newly approved LEMING (LEptons in Muonium INteracting with Gravity) experiment located at the Paul Scherrer Institut (PSI) aims to improve laser spectroscopy measurements on Mu and to measure Mu in free fall. However, state-of-the-art, vacuum Mu sources rely on thermal emission, limiting the feasibility of both scientific goals.
A novel way of Mu production was demonstrated using a thin layer of superfluid helium. We have achieved the production of a Mu beam with ~10 % conversion efficiency and ~30 mrad angular divergence. These results allow for measurements of g on Mu with a precision of ~1% using atom interferometry and to improve the fractional precision of Mu 1S-2S measurements by more than an order of magnitude, compared to thermal sources.

In this talk the first observation of a vacuum Mu being emitted from superfluid helium and an initial characterisation of the novel Mu source will be presented. Furthermore, the resulting prospect to do spectroscopy and measure g will be discussed.

[1] Anderson, E.K., Baker, C.J., Bertsche, W. et al. Observation of the effect of gravity on the motion of antimatter. Nature 621, 716–722 (2023). https://doi.org/10.1038/s41586-023-06527-1

Speaker: Paul Wegmann (ETH Zurich)

Platan - 2024 - Paul Wegmann.pdf

14:30 Absolute charge radii measurements of potassium and chlorine

Muonic atom spectroscopy is a technique that studies the atomic transitions between levels that are occupied by muons orbiting a nucleus. Due to the heavier mass of muons with respect to that of electrons, its atomic orbitals will be substantially closer to the nucleus. Consequently, the sensitivity to nuclear effects is enhanced. In particular, muonic atoms have an increased sensitivity to the finite size correction (~$10^7$ compared to electronic atoms). As a result, absolute nuclear charge radii can be extracted, providing invaluable input for laser spectroscopy experiments in the form of benchmarks [1].

By employing a high-pressure hydrogen cell, with a small deuterium admixture, it became possible to reduce the required target quantity from 10 mg to about 5 µg. This opens the door to measurements on long-lived radioactive isotopes and materials not available in large quantities [2]. In 2022, we performed an experiment that showed implanted targets could be used for the spectroscopy [3]. As a result, samples that have been prepared by employing mass separation and subsequent implantation, can be measured with our technique. Following this success, we did another experimental campaign in October 2023 with the goal of measuring the absolute charge radius of potassium and chlorine isotopes.

In this contribution, we shall report on the experimental method and recent results obtained for muonic x-ray measurements on $^{39, 40, 41}$K and $^{35, 37}$Cl, as well as their implication for future research.

[1] Fricke, Gerhard, K. Heilig, and Herwig F. Schopper. Nuclear charge radii. Vol. 454. Berlin: Springer, 2004.
[2] Adamczak, Andrzej, et al. "Muonic atom spectroscopy with microgram target material." The European Physical Journal A 59.2 (2023): 15.
[3] Heines, Michael, et al. "Muonic x-ray spectroscopy on implanted targets." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 541 (2023): 173-175.

Speaker: Michael Heines (KU Leuven (BE))

PLATAN_muX.pdf

PLATAN_muX.pptx

14:50 Ultra-cold Cs trap for magnetic octupole moment studies and coherent gamma generation

The atom-trap facility at the Ion-Guide Isotope Separator On-Line (IGISOL) at the University of Jyväskylä has been developed for cooling and trapping a chain of isotopes and isomers of caesium [1]. This would allow a high-precision spectroscopy from which a nuclear magnetic octupole moment can be deduced, an important parameter which helps validate nuclear theory and reveal insight on the nuclear structure [2]. Moreover, a Bose-Einstein condensate of 135mCs isomers was shown to be a potential candidate for a long-sought coherent gamma-ray source, an intriguing result of the coherent nature of the degenerate ensemble [3]. The Cs isotopes and isomers are produced via proton-induced fission of a natural uranium target in a helium buffer gas filled ion guide, extracted via gas flow, accelerated electrostatically to 30 keV, mass-separated, and finally delivered to a cold-atom chamber. Installed inside the chamber is a thin yttrium foil where implanted Cs ions can be neutralised and released using resistive heating. A special coating applied on the inner surface of the chamber then allows thermalisation of hot Cs atoms, thereby facilitating a magneto-optical trap (MOT), the initial stage of a cooling and trapping scheme. Well-established optical cooling methods such as optical molasses and degenerate Raman sideband cooling (DRSC) are subsequently applied to obtain a temperature suitable for a probing activity of interest, and ultimately reach the quantum degenerate regime of BEC.
[1] A. Giatzoglou et al., Nucl. Instrum. Methods Phys. Res. A 908 (2018) 367–375.
[2] R.P. de Groote et al., Phys. Lett. B 827 (2022) 136930.
[3] L. Marmugi, P.M. Walker, F. Renzoni, Phys. Lett. B 777 (2018) 281–285.

Speaker: Wirunchana Rattanasakuldilok

PLATAN_Ultra-cold Cs trap for magnetic octupole moment studies and coherent gamma generation.pdf

15:10 → 15:40 Coffee

15:40 → 16:20 Plenary: Plenary 14

Convener: Klaus Wendt

15:40 Towards the study of the Bohr-Weisskopf effect in short lived nuclei using laser-rf double-resonance spectroscopy.

Using convectional collinear laser spectroscopy techniques, the Bohr-Weisskopf effect(BWE) is frequently found to be at a similar level to the experimental uncertainty. Therefore, the study of this effect has been mainly limited to stable isotopes, where higher precision can be obtained. Despite the limited information, this effect could in principle provide significant new information on both the composition of nuclear magnetism and its spatial distribution. At the VITO beamline at ISOLDE, a new programme of research into the BWE has been initiated. Here, a new beamline end station is under construction, in which laser-rf double resonance will be performed. Using this technique, the resolution required for the widescale study of this observable will become available. In this contribution, the developments undertaken will be reviewed and recent results on the BWE presented.

Speaker: Mark Bissell (CERN)

16:00 Probing the nuclear magnetic octupole moment of trapped Sr ions

At the Institute for Nuclear and Radiation Physics of KU Leuven (IKS) we started a project to measure data on the magnetic octupole moment ($\Omega$) of single valence radioactive nuclei. While currently this observable has only scarcely been measured, and is thus poorly understood, preliminary shell model and Density functional theory (DFT) calculations indicate $\Omega$ may display a strong sensitivity to nuclear shell effects, even stronger than the dipole moment. It may also be well suited to probe the distribution of neutrons within the nucleus, and study fundamental properties of nucleons of stable and radioactive isotopes. This objective presents several challenges, both technical and scientific, as there are presently no methods that reach the precision required to measure $\Omega$ for short-lived isotopes of any element. In this context, the first study will be performed on the stable $^{87}Sr^+$. With 49 neutrons, $^{87}Sr^+$ is characterized by a single hole in the N=50 closed shell, which makes it more easily compared with a variety of theoretical calculations. Once measurements with $^{87}Sr$ are demonstrated, it could be possible to extend them to the long-lived $^{83,85,89}Sr^+$ here at IKS. A non-zero $\Omega$ leads to small energy shift of the hyperfine structure. We aim to measure these splitting with a precision of the order of 1-10 Hz on the hyperfine intervals, which should result in a measurement of $\Omega$ with a precision of 10$\%$. This has been demonstrated feasible with stable
$^{137}Ba^+$, homologue of $Sr^+$, inside ion traps [1]. This contribution aims to offer a broad understanding of the project and present the latest developments in the laboratory.

References
[1] N. C. Lewty, B. L. Chuah, R. Cazan, B. K. Sahoo, and M. D. Barrett, “Spectroscopy
on a single trapped 137ba+ ion for nuclear magnetic octupole moment determination,”
Optics Express, Sep. 10, 2012. doi: 10.1364/OE.20.021379.

Speaker: Pierre Lassegues (KU Leuven (BE))

16:20 → 16:30 Conference Photo

16:30 → 17:50 Free time

17:50 → 18:00 Boarding

18:00 → 18:45 Boat cruise to Savutuvan Apaja

19:00 → 19:01 Conference dinner

22:00 → 22:01 Bus transport back to city center/Alba

Friday 14 June

09:00 → 10:30 Plenary: 15

Convener: Mikael Reponen (University of Jyvaskyla (FI))

09:00 CERN-ISOLDE’s new high-resolution laser ion source PI-LIST: Results, characteristics, and developments

On-line in-source laser resonance ionization is a highly sensitive tool for nuclear structure investigations [1]. While the efficiency of this technique is unrivaled, the experimental resolution is ultimately limited by Doppler broadening in the hot cavity required to ensure atom volatilization. At typical operation temperatures around 2000 °C, this leads to a several GHz limit, whereas precise measurements of nuclear magnetic and quadrupole moments often require resolving hyperfine structure splittings well below the GHz regime.

A new laser ion source design has been implemented at CERN-ISOLDE to provide in-source spectroscopy capabilities down to experimental linewidths around 100 MHz, an order of magnitude below usual limitations. It is based on the Laser Ion Source and Trap (LIST) [2], tailored for high purity ion beam production. In the new so-called Perpendicularly Illuminated LIST (PI-LIST) mode [3], a crossed laser / atom beam geometry reduces the effective Doppler broadening by addressing only the transversal velocity components of the effusing atom ensemble – a method that had previously become the standard for very successful off-line experiments at Mainz University [4, 5, 6].

We report on the first-time on-line application of the PI-LIST [7] for investigations on octupole deformation in neutron-rich actinium isotopes [8]. Limitations, prospects and developments are discussed, and several application cases mainly focused on the lanthanide and actinide region are presented.

References
[1] Fedosseev et al., J. Phys. G: Nucl. Part. Phys. 44 084006 (2017)
[2] Fink et al., Phys. Rev. X 5, 011018 (2015)
[3] Heinke et al., Hyperfine Interact 238, 6 (2017)
[4] Studer et al., Eur. Phys. J. A 56, 69 (2020)
[5] Kron et al., Phys. Rev. C 102, 034307 (2020)
[6] Weber et al., Phys. Rev. C 107, 034313 (2023)
[7] Heinke et al., NIMB 541,8-12 (2023)
[8] Verstraelen et al., Phys. Rev. C 100, 044321 (2019)

Speaker: Reinhard Heinke (CERN)

2024-06-14 Heinke PLATAN.pdf

2024-06-14 Heinke PLATAN.pptx

09:30 In-source Laser Spectroscopy Studies of Neutron-rich Thallium at IDS/ RILIS-ISOLDE

Laser spectroscopy is one of the most powerful tools for studying ground and isomeric state nuclear properties. By observing small changes in atomic transitions, we can deduce the nuclear spin, electromagnetic moments, and changes in mean-square charge radii across long chains of isotopes. This allows us to study how the shapes and the configurations of the nuclei vary along the chain and hence to test our models that attempt to describe how nuclear structures evolve across the chart.

In this contribution, I will present the results from hyperfine structure and isotope shift studies of neutron-rich $^{207-209}$Tl performed at the ISOLDE Decay Station (IDS), combined with the application of the Laser Ion Source and Trap (LIST) to suppress the isobaric contamination typical to this mass region. The changes in the mean-square charge radii and magnetic dipole moments were extracted. The results display a kink [1] in the mean-square charge radii along the Tl isotopic chain when crossing the N=126 shell closure. The magnetic dipole moments for $1/2^+$ thallium ground states have a large jump at N=126. Theoretical calculations including particle-vibrational coupling with the self-consistent theory of finite Fermi systems based on energy density functional are used to model the data [2].

[1]: P. Campbell, I. D. Moore, and M. R. Pearson, Prog. Part. Nucl. Phys. 86, 127 (2016).
[2]: Z. Yue, A.N. Andreyev, A.E. Barzakh et al. Magnetic moments of thallium isotopes in the vicinity of magic 𝑁 = 126, Physics Letters B 849 (2024) 138452

Speaker: Zixuan Yue (University of York (GB))

09:50 On-line resonance ionization laser ion source development at the RAON ISOL facility

Resonance ionization laser ion source (RILIS) has been developed as part of the ISOL ion sources at RAON in the Institute for Rare Isotope Science, Korea. The RAON RILIS based on Ti:sapphire lasers has been developed with a long laser beam transport system over 30 m. To develop optimal laser ionization schemes and investigate the RILIS efficiency, an off-line test facility adjacent to the RILIS laser room has been newly equipped. After the successful operation of RILIS with stable Sn and Al isotopes at the off-line test facility, the current effort aims at the on-line operation of the RAON RILIS to provide radioactive ion beams to the applications, such as collinear laser spectroscopy (CLaSsy) and mass measurement system (MMS).

Speaker: Dr Sung Jong Park (Institute for Rare Isotope Science)

10:10 Double-beta decay Q-value measurements with the JYFLTRAP Penning trap

The observation of double-beta decays and double-electron captures have become an important tool in the search for physics beyond the Standard Model (SM). These decays have been proposed to decay by emitting either two neutrinos or no neutrinos. While the two neutrino mode has been observed [1], the proposed neutrinoless decay mode requires the neutrino to be its own antiparticle (a Majorana particle), which would be a violation of the SM. To determine the suitability of an isotope for these observations, the energy released in the decay (Q-value) needs to be known precisely in order to calculate its half-life (generally $\geq10^{25}$ a [1]), and thus the feasibility of observing the neutrinoless decay mode and to separate the decay signal from background.

In three recent measurements at the Ion Guide Isotope Separator On-Line (IGISOL) facility [2] in the University of Jyväskylä, the JYFLTRAP double Penning trap [3] employing the Phase-Imaging Ion-Cyclotron Resonance (PI-ICR) method [4] was used to determine the Q$_{\beta^-\beta^-}$ of $^{104}$Ru, $^{122}$Sn, $^{142}$Ce and $^{148}$Nd, and Q$_{ECEC}$ of $^{120}$Te. In addition, the precisely known Q$_{ECEC}$ of $^{102}$Pd and $^{150}$Nd, and Q$_{\beta^-\beta^-}$ of $^{124}$Sn were re-measured. The ions were produced using two electric discharge ion sources. A precision of $\sim$100 eVs was reached for the Q-values. Most of our measurements are in agreement with their literature values in the Atomic Mass Evaluation [5]. In my contribution, I will present the JYFLTRAP measurement setup, the PI-ICR measurement technique and initial results of our measurements.

[1]M. J. Dolinski et. al, Annu. Rev. Nucl. Part. Sci. 69 219 (2019)
[2]I. Moore et. al, Nucl. Instrum. Methods Phys. Res. B 317 208 (2013)
[3]T. Eronen et. al, Eur. Phys. J. A. 48 46 (2012)
[4]S. Eliseev et. al, Phys. Rev. Lett. 110 082501 (2013)
[5]M. Wang et. al, Chinese Phys. C 45 030003 (2021)

Speaker: Jouni Ruotsalainen (University of Jyväskylä)

10:30 → 11:00 Coffee

11:00 → 12:00 Plenary: 16

Convener: Anna Kwiatkowski

11:00 High precision decay energy measurements of low Q-value beta decays with JYFLTRAP at IGISOL

High-precision measurements of single β$^{±}$ decays or electron capture (EC) are the most model-independent methods to determine the absolute scale of the (anti)neutrino mass. Decay transitions with the lowest possible Q value are desirable. Currently, only three nuclei with low ground-state-to-ground-state (gs-to-gs) decay Q values are employed for direct neutrino-mass measurements [1-3]. Further explorations for low Q-value ground-state–to-excited-state (gs-to-es) β decay or EC transitions are crucial. In addition to the slightly positive Q values, the slightly negative Q values can also be of interest in seeking for a new type of transition process, like the virtual radiative “detour” transitions (RDT) [1]. A precise and accurate determination of the decay Q value is extremely important in the context of searches for the absolute (anti)neutrino mass scale or for RDT study, with potential implications for low-energy solar-neutrino detection.
Recently, multiple gs-to-gs low-Q-value beta-decay candidates ($^{72,76,77}$As, $^{75}$Se, $^{75}$Ge, $^{95-97}$Tc, $^{111}$In, $^{131}$I, $^{136}$Cs, $^{155}$Tb, and $^{159}$Dy) have been measured with JYFLTRAP at the University of Jyväskylä [1-3]. The measured high-precision Q values, coupled with nuclear energy level data, are used to determine the energetic permissibility of these low Q-value gs-to-es beta decay candidates, and ascertain the absolute Q value. Subsequently, the suitability of these beta decays with low Q values for direct searches for neutrino mass or for RDT study can be inferred. In this report, the state-of-the-art Penning Trap experimental techniques to determine the gs-to-gs Q value to a relative uncertainty of ~10$^{-9}$, along with the Q-value measurement results of select cases for neutrino mass determination, RDT study, potential implications for low-energy solar-neutrino detection. will be discussed.

Reference:
[1] Z. Ge, T. Eronen et al., Phys. Rev. C, 108:045502 (2023).
[2] Z. Ge, T. Eronen et al., Phys. Rev. Lett., 127:272301(2021).
[3] Z. Ge, T. Eronen et al., Phys. Lett. B, 832:137226 (2022).

Speaker: Dr zhuang ge (UNIVERSITY OF JYVÄSKYLÄ)

11:20 Update on TRIUMF's resonant ionization laser ion source(s) and the nuclear spin polarized beams program

The laser applications group at TRIUMF - Canada's particle accelerator centre is tasked to provide clean and intense beams of radioactive isotopes for user experiments. This is done through in-source laser resonance ionization (running a laser ion source or derivatives thereof). Beam delivery activities and highlights of the RIB delivery and development program of the past years will be descirbed and discussed.
In addition the group is tasked with providing nuclear spin polarized beams for experiments such as beta detected nuclear magnetic resonance spectroscopy - which is used for materials and bio sciences, as well as nuclear structure investigations. With increased demand for specific spin polarized species the combined polarizer- and collinear fast beam laser spectroscopy beamline is undergoing upgrades to facilitate new user programs in collinear fast beam laser spectroscopy, as well as the coupling of the GRIFFIN nuclear decay spectrometer to the polarizer.
Current activities, upgrades and future plans for polarized beams and collinear fast beam laser spectroscopy will be presented.

Speaker: Jens Lassen

11:40 Neither last nor least, just LIST – derivatives of a versatile laser ion source and their applications

Selective and efficient ionization using multi-step resonant laser excitation processes has become the most versatile and widely used technique in the production and study of exotic species, both for research on their atomic or nuclear structure at the different on-line facilities worldwide as well as for applications in isotope purification for fundamental investigations or for the production of nuclear medical radioisotopes. The key shortcoming of the inevitable occurrence of interfering non-selective surface ionization on hot surfaces of the laser ion source unit has been successfully addressed by the development and implementation of the laser ion source trap (LIST), which ensures the suppression of the isobaric background by orders of magnitude with only a moderate loss of efficiency [1,2].
Based on the early, rather sophisticated concepts of the LIST formulated 20 years ago [3], several adaptations - both simplifications and specific refinements – have led to a variety of applications. Today, aside from isobar suppression, these focus on direct high-resolution in-source laser spectroscopy on hyperfine structures and isotope shifts of rare species off- and on-line in the (PI)-LIST [4,5]. Furthermore, the recent upgrade to the field ionization (FI)-LIST has paved the way for the precision determination of ionization potentials on exotic species [6]. After a brief review of the development steps from the first LIST concept, the presentation will focus on the investigations carried out on stable and long-lived radioisotopes performed at the off-line RIB facility RISIKO of Mainz University using the PI- and FI-LIST.
[1] D. Fink et al., NIM B344, 89 (2015)
[2] D. Fink et al., Phys. Rev. X5, 011018 (2015)
[3] K. Blaum et al., NIM B204, 331 (2003)
[4] T. Kron et al., Phys. Rev. C102 034307 (2020)
[5] R. Heinke et al., NIM B541, 8 (2023)
[6] M. Kaja et al., NIM B547, 165213 (2024)

Speaker: Klaus Wendt

12:00 → 12:30 Closing ceremony

12:30 → 14:00 Lunch