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Te use of radioactive molecules for fundamental physics research is a developing interdisciplinary field limited dominantly by their scarce availability. In this work, radioactive molecular ion beams containing actinide nuclei extracted from uranium carbide targets are produced via the Isotope Separation On-Line technique at the CERN-ISOLDE facility. Two methods of molecular beam production are studied: extraction of molecular ion beams from the ion source, and formation of molecular ions from the mass-separated ion beam in a gas-filled radio-frequency quadrupole ion trap. Ion currents of U+, UO1−3+, UC1−3+, UF1−4+, UF1,2O1,2+are reported. Metastable tantalum and uranium fluoride molecular ions are identified. Formation of UO1−3+, U(OH)1−3+, UC1−3+, UF1,2O1,2+from mass-separated beams of U+, UF1,2+with residual gas is observed in the ion trap. The effect of trapping time on molecular formation is presented.

ISOLDE’s Offline 2 laboratory has been upgraded to facilitate development for the production and study of molecular ion beams. New gas injection systems have been implemented for both molecular formation in the ion source and in the radio-frequency quadrupole ion trap used for beam preparation. MagneToF detectors and time-resolved single ion counting data acquisition have been implemented for low intensity beams and studies of laser-atom or laser-molecule interactions. We present a study of the formation and ionization of BaF+using the upgraded facility.

The feasibility of Rutherfordium IP measurements with the electron-impact source VADIS has been studied theoretically by estimation of adsorption properties and first experiments of ion source efficiency in function of mean electron energy. • IPs of noble gases could be derived within an error of 0.1 V following an extrapolation method. • Adsorption properties suggest, that temperatures above nominal conditions are necessary. • Further R&D is needed, which might include the partial redesign of the source., Poster presented at the 6th International Conference on the Chemistry and Physics of the Transactinide Elements (TAN 19)

This note describes systematic investigations of isotope production channels in thick targets exposed to the PS Booster (PSB) beam at ISOLDE. Recent experimental results have shown that new important radionuclide beams could be produced such as Pb-nat(p,x)Hg-208 in thick lead targets. We introduce in this note calculations of the production yield of isotopes generated from the creation and re-interaction of α particles in thick lead, bismuth, thorium and uranium targets irradiated by the 1.4 GeV proton beam delivered from the CERN PS Booster at ISOLDE. It gives the production yields of several isotopes that are not directly predicted with FLUKA and its RESNUCLEI production card while keeping a reasonable CPU time. These isotopes are particularly produced from (α, xp) and (3H, yp) reactions, with x = 4, 5, 6 and y = 3, 4, 5. The production yields have been calculated for Pb-208, Bi-209, Th-232 and U-238 target nuclei. The TENDL-2019 library has been used to recover the production cross-sections together with the afore-mentioned version of FLUKA to score the α and 3H fluences. The calculation method was verified with the FLUKA predictions for the Bi-209(α,2n) reaction and the At-211 production yield, an isotope of high interest in nuclear medicine, as well as with the radionuclides which are produced via (3H,3p) and (α,2p) reactions. The computation and experimental data are in good agreement, providing an alternative method to evaluate the inventories of radionuclides of potential interest for target waste management, and for the physics and medical programs at ISOLDE and MEDICIS.

Offline 2 is the most recent mass separator beamline at the Isotope Separator On-line DEvice (ISOLDE) infrastructure, dedicated for developments of ion beam production and manipulations. It is a non-radioactive laboratory which has been constructed to mimic the ion beam production and ion beam delivery at the on-line facility at ISOLDE. Here, positive or negative ion beams with kinetic energies of up to 60 keV can be produced and extracted. One of the main features of the Offline 2 beamline is a dedicated Radio-Frequency Quadrupole cooler and buncher (RFQcb) which allows to deliver both continuous ion beams as well as bunched beams. This RFQcb installation serves as a development platform for its twin installation, the ISOLDE cooler (ISCOOL), which is in operation at the ISOLDE on-line facility. To complete the installation, a dedicated laser laboratory has been constructed in an adjacent room to the mass separator with an optical path towards the ion source through a window in the separator magnet. This enables the use and further development of the Resonance Ionization Laser Ion Source (RILIS) towards better beam purification and higher spectral resolution for in-source laser spectroscopy. This new facility will be used for ion source developments, beam optics and beam manipulation studies aiming to improve ion beam quality and the performance of target-ion sources during on-line operation at the ISOLDE facility. In this report, the design and features of the facility are described.

The design and placement of passive measures for the improvement as well as the targeted adjustment of the vibroacoustic behaviour of technical products is often based on empirically determined rules or guidelines. Due to their general validity, potential for improvement often remains unused. Simulative optimization procedures, on the other hand, are often very time-consuming due to the frequency dependence of acoustic phenomena and many iterations. This dissertation is dedicated to the development of identification criteria for passive measures in early design phases, which already provide a placement and design proposal after one or a few calculation steps. Essential adjusting screws for influencing the vibroacoustic behaviour of technical products are changes in mass, stiffness and damping. Therefore, beads, damping layers and point masses are used as representative examples of these adjusting screws. At the beginning of the thesis, a general classification of acoustic principles and measures in the methodological terminology of product development (Design to Acoustics) is given and a suitable acoustic assessment of design variants is discussed. The core of the thesis are numerical position and design studies of the exemplary measures on a rectangular plate, based on direct solutions using the finite element method. A suitable assessment quantity for the variants is the structure-borne sound level. The aim is to minimise this quantity in a defined critical frequency range. An application-oriented focus is set and a manufacturing-oriented design is taken into account. Correlations between distributions of physical quantities of the structure and suitable positions of the measure form the basis for deriving identification criteria. The studies show that identification criteria can be obtained for all three measures with different robustness regarding changing boundary conditions and critical frequency ranges. The procedure and the most suitable criteria are successfully applied on a realistic car body structure (splash wall) at the end of the thesis. The identification criteria developed thus support the process towards an acoustic-oriented design and development in the early design phases., Das Design und die Platzierung passiver Maßnahmen zur Verbesserung sowie der gezielten Einstellung des vibroakustischen Verhaltens von technischen Produkten basiert häufig auf empirisch ermittelten Regeln oder Leitlinien. Aufgrund ihrer Allgemeingültigkeit bleibt Verbesserungspotential häufig ungenutzt. Simulative Optimierungsprozeduren sind dagegen aufgrund der Frequenzabhängigkeit akustischer Phänomene und vieler Iterationen oft sehr zeit- und kostenintensiv. Die vorliegende Dissertation widmet sich der Erarbeitung von Identifikationskriterien für passive Maßnahmen in frühen Entwicklungsphasen, die bereits nach einem oder wenigen Berechnungsschritten einen Platzierungs- und Designvorschlag liefern. Wesentliche Stellschrauben bei der Beeinflussung des vibroakustischen Verhaltens von technischen Produkten sind Änderungen der Masse, Steifigkeit und Dämpfung. Als repräsentative Beispiele für diese Stellschrauben werden daher Sicken, Dämpfungslagen und Punktmassen als Maßnahmen herangezogen. Zu Beginn der Arbeit wird eine übergeordnete Einordnung akustischer Prinzipien und Maßnahmen in die methodische Terminologie der Produktentwicklung (Design to Acoustics) unternommen sowie eine geeignete akustische Bewertung von Designvarianten diskutiert. Kern der Thesis sind numerische Positions- und Designstudien der exemplarischen Maßnahmen anhand einer Rechteckplatte, auf Basis direkter Lösungen mit Hilfe der Finite-Elemente-Methode. Als eine geeignete Bewertungsgröße der Varianten ergibt sich das Körperschallmaß. Das Ziel ist es, diese Größe in einem definierten kritischen Frequenzbereich zu minimieren. Hierbei wird ein anwendungsnaher Fokus gesetzt und die fertigungsgerechte Gestaltung mitberücksichtigt. Korrelationen zwischen Verteilungen physikalischer Größen der Struktur und geeigneten Positionen der Maßnahme bilden die Grundlage zur Ableitung von Identifikationskriterien. Die Studien zeigen, dass sich Identifikationskriterien für alle drei Maßnahmen mit unterschiedlicher Robustheit gegenüber sich ändernden Randbedingungen und kritischen Frequenzbereichen ableiten lassen. Das Vorgehen und die Kriterien die sich am besten eignen werden am Ende der Arbeit an einer realistischen Karosseriestruktur (Spritzwand) erfolgreich angewendet. Die erarbeiteten Identifikationskriterien unterstützen somit den Prozess hin zum akustikgerechten Entwickeln und Konstruieren in frühen Phasen der Produktentwicklung., Schriften des Instituts für Akustik, vol. 2

Thursday 14 April 2022 Contribution X-O41 Chair: E. Colineau

Contribution ID:57 Type:Invited Tuesday, December 14, 2021 2:40 PM (15 minutes)

The spectroscopic quadrupole moments of the odd–even Mn isotopes between N=28 and N=38 have been measured using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. In order to increase sensitivity to the quadrupole interaction, the measurements have been done using a transition in the ion rather than in the atom, with the additional advantage of better spectroscopic efficiency. Since the chosen transition is from a metastable state, optical pumping in ISOLDE’s cooler and buncher (ISCOOL) was used to populate this state. The extracted quadrupole moments are compared to large-scale shell model predictions using three effective interactions, GXPF1A, LNPS and modified A3DA. The inclusion of both the 1νg9/2and 2νd5/2orbitals in the model space is shown to be necessary to reproduce the observed increase in the quadrupole deformation from N=36 onwards. Specifically, the inclusion of the 2νd5/2orbital induces an increase in neutron and proton excitations across the reduced gaps at N=40and Z=28, leading to an increase in deformation above N=36.

The spectroscopic quadrupole moments of the odd���even Mn isotopes between N=28 and N=38 have been measured using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. In order to increase sensitivity to the quadrupole interaction, the measurements have been done using a transition in the ion rather than in the atom, with the additional advantage of better spectroscopic efficiency. Since the chosen transition is from a metastable state, optical pumping in ISOLDE���s cooler and buncher (ISCOOL) was used to populate this state. The extracted quadrupole moments are compared to large-scale shell model predictions using three effective interactions, GXPF1A, LNPS and modified A3DA. The inclusion of both the 1��g9/2and 2��d5/2orbitals in the model space is shown to be necessary to reproduce the observed increase in the quadrupole deformation from N=36 onwards. Specifically, the inclusion of the 2��d5/2orbital induces an increase in neutron and proton excitations across the reduced gaps at N=40and Z=28, leading to an increase in deformation above N=36.