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Comparative Study of Quarkonium Transport in Hot QCD Matter
No full textInternational audienceThis document summarizes the efforts of the EMMI Rapid Reaction Task Force on "Suppression and (re)generation of quarkonium in heavy-ion collisions at the LHC", centered around their 2019 and 2022 meetings. It provides a review of existing experimental results and theoretical approaches, including lattice QCD calculations and semiclassical and quantum approaches for the dynamical evolution of quarkonia in the quark-gluon plasma as probed in high-energy heavy-ion collisions. The key ingredients of the transport models are itemized to facilitate comparisons of calculated quantities such as reaction rates, binding energies, and nuclear modification factors. A diagnostic assessment of the various results is attempted and coupled with an outlook for the future
Production of Pb from enriched Tl using deuteron beams
No full textInternational audienceLead-203 is a SPECT emitter that can be used in theranostic applications as an imaging counterpart of lead-212 which is intended to be used for alpha therapy as lead-212/bismuth-212 in-vivo generator. In our study, we explore the production of lead-203 using enriched thallium-205 target irradiated by a deuteron beam. Excitation functions of deuteron induced reactions leading to the formation of 204m,203m2+m1+g,202m,201m+gPb, 202Tl and 203m+gHg isotopes were determined experimentally in the energy range from 21 MeV to 34 MeV. Cross sections were measured using the stacked foils technique and a set of two monitor foils, natNi and natTi for beam intensity evaluation. The experimental excitation functions of the investigated reactions were compared with the published data and also with the TENDL-2021 nuclear database. From our experimental data, we calculated lead-203 thick target yield in the energy range between 30 MeV and 32.5 MeV to be 56.7 MBq/μAh ±6.1 MBq/μAh. This value is compatible with large batch production showing that deuteron beams can be used for a routine production process. However, special attention must be paid to 203Hg and other lead contaminants. •Deuteron induced reactions on thallium enriched to 205 (205Tl) up to 34 MeV.•Target preparation of 205Tl using the electrodeposition technique.•Stacked foil irradiation.•Production of 203Pb for nuclear medicine applications.•Comparison of thick target yields between proton and deuteron irradiation
Manufacturing and characterization of Gd targets for the production of terbium radionuclides for nuclear medicine
No full textInternational audienceThis study explores gadolinium (Gd) target production for nuclear medicine, focusing on Gd targets for producing terbium-155 (Tb-155), which is used in SPECT imaging. Thin targets are required for cross-section measurements, while thicker targets are needed for large-scale production. The molecular plating (MP) technique was applied to create thin targets on titanium (Ti) substrates, with characterization performed using SEM, ICP-OES, and other analyses. This research aims to explore how different parameters affect the MP process, with initial results proving highly promising
Production Cross Section Measurements of the natNi(d,x)61Cu Reaction
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PRISMAP School on radionuclide production: Exotic cyclotrons for innovative radionuclides
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Modélisation moléculaire de l'adsorption de l'hydrogène gazeux dans les environnements argileux hydratés dans le contexte de stockage géologique des déchets radioactifs
No full textClay-rich formations are considered as optimal host rock for deep geological repository facilities for high-level radioactive waste. Gas, particularly H2, may form during long-term storage through mechanisms such as anoxic corrosion and water radiolysis, potentially leading to gas pressure buildup and fractures in the surrounding host rock. Molecular-scale understanding of H2 behavior in clay is essential for safe geological disposaland storage, and for the developing effective strategies. In this thesis, montmorillonite, which is widely found in host rock compositions and used as an engineered barrier, is chosen as the clay model. Atomistic simulations of H2 adsorption within the interlayers of hydrated Na-, Ca-, and Cs-montmorillonites are conducted at 25, 50, and 90◦C, up to 120 bar using Monte Carlo and hybrid methods. To this end, the impact of several other factors factors, including the presence of water and pore size are investigated, aiming to improve the fundamental understanding of the physical and chemical processes governing interactions among H2, aqueous solutions, and clay. Furthermore, hydrogen adsorption under extreme conditions is explored to determine the point of saturation in clays.Les formations riches en argile sont considérées comme des roches hôtes optimales pour les installations de stockage géologique en profondeur des déchets radioactifs de haute activité. Des gaz, notamment le H2, peuvent se former au cours du stockage à long terme par des mécanismes tels que la corrosion anoxique et la radiolyse de l'eau, pouvant potentiellement entraîner une accumulation de pression de gaz et des fractures dans la roche hôte environnante. Une compréhension à l'échelle moléculaire du comportement du H2 dans l'argile est essentielle pour un stockage géologique sûr et efficace, ainsi que pour le développement de stratégies efficaces. Dans cette thèse, la montmorillonite, largement présente dans les compositions de roches hôtes et utilisée comme barrière technique, est choisie comme modèle d'argile. Des simulations atomistiques de l'adsorption de H2 dans les intercalaires des montmorillonites hydratées de Na, Ca et Cs sont réalisées à 25, 50 et 90°C, jusqu'à 120 bar, en utilisant des méthodes de Monte Carlo et hybrides. À cette fin, l'impact de plusieurs autres facteurs, y compris la présence d'eau et la taille des pores, est étudié, dans le but d'améliorer la compréhension fondamentale des processus physiques et chimiques régissant les interactions entre H2, les solutions aqueuses et l'argile. De plus, l'adsorption d'hydrogène dans des conditions extrêmes est explorée pour déterminer le point de saturation dans les argiles
Studies of different production paths for 155 Tb using Gd targets : from target manufacturing to Tb/Gd separation
No full textInternational audienceShort-lived radioisotopes of the terbium (Tb) family show great prospects in theranostics: the 149Tb can be used for alpha therapy, the 152Tb, can be applied for positron emission tomography (PET), the 155Tb can be used for single photon emission tomography (SPECT) and Auger therapy, and finally the 161Tb can be an alternative to the 177Lu for β-therapy. We focused on 155Tb production and studies show that its production might be feasible in low-energy radiopharmaceutical cyclotrons with proton beams on 155Gd-enriched raw material [1]. However, delivering this energy at GIP ARRONAX is not possible. We then explored the production of 155Tb using deuteron beams with its 20 MeV beam [2]. At this energy, 153Tb production is impossible (T1/2 = 2.34 d for 153Tb and 5.36 d for 155Tb). For this work, two kinds of targets were developed: a thin one for cross section measurements to investigate 155Tb production and radio-impurities and a thick one for future large-scale production of 155Tb. To make thin targets containing enriched 155Gd for cross section measurements, the raw material, 155Gd2O3 powder, must be manufactured to obtain a solid target for irradiation. The co-electrodeposition technique involves trapping 155Gd2O3 in a Ni deposit [3]. The cross section values of various nuclear reactions have been published [4], showing that the highest 155Tb cross section value was 798 mb at a deuteron energy of 14.2 MeV. However, the presence of radio-impurities from Ni caused more complex γ-spectrometry measurements by increasing the dead time during counting with the HPGe detector. To address the issue, we investigated molecular plating, which allows us to obtain a deposit through electrodeposition in organic media. This technique avoids the presence of Ni and enables the formation of a gadolinium deposit, reducing the dead time during HPGe detector counting. Deposits containing 2 mg of Gd were obtained, which will be tested with natural Gd under irradiation. These results will be compared to previous authors to ensure feasibility before using enriched 155Gd2O3.Thick targets were manufactured to enable large-scale production of 155Tb. They were made by pressing powdered Gd2O3 to form a pellet. A mass of 0.6 g of enriched 155Gd2O3 (diameter = 2 cm) was subjected to a one-hour irradiation at 15 MeV and 500 nA [4]. The produced activity of 155Tb was 10.2 ± 0.7 MBq/µAh with a produced activity of 156Tb at 1.3 ± 0.1 MBq/µAh. 156Tb was produced from 5.7% of 156Gd (threshold energy = 5.52 MeV via the 156Gd(d,2n)156Tb nuclear reaction), as well as from 155Gd. At the end of the bombardment, the purity of the 155Tb ratio was 87.3%; after 9 days of cooling, this value increased slightly to 89%.The chemical separation between Gd and Tb was investigated using LN resin (from Triskem). This work aims to obtain a solution with a 155Tb/Gd ratio greater than 1/100 to be sent to CERN-MEDICIS for mass separation. 5 irradiations were carried out using natural Gd foils at the ARRONAX cyclotron. Proton beams were used at 55 MeV with a cumulative intensity of 360 µAh. The best 155Tb/Gd ratio achived was 1/2. A process utilizing two columns containing LN resin was used to obtain this value.Our research demonstrates that we can produce 155Tb on a large scale with deuteron beams; however, though there is some pollution from the 156Tb radio-impurity. This contamination occurs regardless of whether proton or deuteron beams are used. 156Tb is always produced for deuteron beams due to 0 MeV threshold energy of 155Gd. For proton beams, 156Tb is not produced from 155Gd, but the presence of 156Gd impurity in the 155Gd enriched raw material (up to 8%) leads to 156Tb contamination. To increase the purity of 155Tb, mass separation must be used. Another possibility to produce high-purity 155Tb is to use the indirect route through 155Dy (T1/2 = 9.9h). 156Tb cannot be produced in this case because 156Dy is a stable element. While 157Tb can be produced from 157Dy, the yield is very low [5]. 155Dy can be created by bombarding 155Gd or 156Gd with alpha beams, which the ARRONAX cyclotron can deliver. The cross sections will be measured and the enriched 155Gd or 156Gd deposit will be manufactured using Molecular Plating.[1]G. Dellepiane et al., “Cross section measurement of terbium radioisotopes for an optimized 155Tb production with an 18 MeV medical PET cyclotron,” Applied Radiation and Isotopes, vol. 184, p. 110175, Jun. 2022, doi: 10.1016/j.apradiso.2022.110175.[2]F. Haddad et al., “ARRONAX, a high-energy and high-intensity cyclotron for nuclear medicine,” Eur J Nucl Med Mol Imaging, vol. 35, no. 7, pp. 1377–1387, Jul. 2008, doi: 10.1007/s00259-008-0802-5.[3]Y. Wang, T. Sounalet, A. Guertin, F. Haddad, N. Michel, and E. Nigron, “Electrochemical co-deposition of Ni–Gd2O3 for composite thin targets preparation: Production of 155Tb as a case study,” Applied Radiation and Isotopes, vol. 186, p. 110287, Aug. 2022, doi: 10.1016/j.apradiso.2022.110287.[4]Y. Wang, T. Sounalet, A. Guertin, E. Nigron, N. Michel, and F. Haddad, “Study of terbium production from enriched Gd targets via the reaction 155Gd(d,2n)155Tb,” Applied Radiation and Isotopes, vol. 201, p. 110996, Nov. 2023, doi: 10.1016/j.apradiso.2023.110996.[5]A. N. Moiseeva, R. A. Aliev, E. B. Furkina, V. I. Novikov, and V. N. Unezhev, “New method for production of 155Tb via 155Dy by irradiation of natGd by medium energy alpha particles,” Nuclear Medicine and Biology, vol. 106–107, pp. 52–61, Mar. 2022, doi: 10.1016/j.nucmedbio.2021.12.004
Quarkonium production in pp and heavy-ion collisions
No full textInternational audienceWe describe bottomonium production not only in pp collisions but also in heavy-ion collisions by using the Remler's formalism where quarkonium density operator is applied to all possible combination of heavy quark and heavy antiquark pairs. In pp collisions heavy (anti)quark momentum is provided by the PYTHIA event generator after rescaling and rapidity to imitate the FONLL calculations. Then spatial separation between heavy quark and heavy antiquark is introduced based on the uncertainty principle. In heavy-ion collisions quarkonium wavefunction changes with temperature assuming heavy quark potential equals the free energy of heavy quark and heavy antiquark system in heat bath. The density operator is updated whenever heavy quark or heavy antiquark scatters in QGP produced in heavy-ion collisions. Our results are consistent with the experimental data from ALICE and CMS Collaborations assuming that the interaction rate of heavy (anti)quark in quarkonium is suppressed to 10 % that of unbound heavy (anti)quark. We also find that off-diagonal recombination of bottomonium barely happens even in Pb+Pb collisions at TeV
Observation of abnormal suppression of (980) production in pPb collisions at = 5.02 TeV
No full textInternational audienceThe dependence of (980) production on the final-state charged-particle multiplicity in pPb collisions at TeV is reported. The production of (980) is measured with the ALICE detector via the decay channel in a midrapidity region of . Particle yield ratios of (980) to and (892) are found to be decreasing with increasing charged-particle multiplicity. The magnitude of the suppression of the (980)/ and (980)/(892) yield ratios is found to be dependent on the transverse momentum , suggesting different mechanisms responsible for the measured effects. Furthermore, the nuclear modification factor of (980) is measured in various multiplicity ranges. The shows a strong suppression of the (980) production in the region up to about 4 GeV/. The results on the particle yield ratios and for (980) may help to understand the late hadronic phase in pPb collisions and the nature of the internal structure of (980) particle
Reactor antineutrino flux and anomaly
No full textInternational audienceReactor antineutrinos have played a significant role in establishing the standard model of particle physics and the theory of neutrino oscillations. In this article, we review the reactor antineutrino flux and in particular the reactor antineutrino anomaly (RAA) coined over a decade ago. RAA refers to a deficit of the measured antineutrino inverse beta decay rates at very short-baseline reactor experiments compared to the theoretically improved predictions (i.e. the Huber-Mueller model). Since the resolution of several previous experimental anomalies have led to the discovery of non-zero neutrino mass and mixing, many efforts have been invested to study the origin of RAA both experimentally and theoretically. The progress includes the observation of discrepancies in antineutrino energy spectrum between data and the Huber-Mueller model, the re-evaluation of the Huber-Mueller model uncertainties, the potential isotope-dependent rate deficits, and the better agreement between data and new model predictions using the improved summation method. These developments disfavor the hypothesis of a light sterile neutrino as the explanation of RAA and supports the deficiencies of Huber-Mueller model as the origin. Looking forward, more effort from both the theoretical and experimental sides is needed to fully understand the root of RAA and to make accurate predictions of reactor antineutrino flux and energy spectrum for future discoveries