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Mass testing and characterization of 20-inch PMTs for JUNO
No full textInternational audienceMain goal of the JUNO experiment is to determine the neutrino mass ordering using a 20kt liquid-scintillator detector. Its key feature is an excellent energy resolution of at least 3 % at 1 MeV, for which its instruments need to meet a certain quality and thus have to be fully characterized. More than 20,000 20-inch PMTs have been received and assessed by JUNO after a detailed testing program which began in 2017 and elapsed for about four years. Based on this mass characterization and a set of specific requirements, a good quality of all accepted PMTs could be ascertained. This paper presents the performed testing procedure with the designed testing systems as well as the statistical characteristics of all 20-inch PMTs intended to be used in the JUNO experiment, covering more than fifteen performance parameters including the photocathode uniformity. This constitutes the largest sample of 20-inch PMTs ever produced and studied in detail to date, i.e. 15,000 of the newly developed 20-inch MCP-PMTs from Northern Night Vision Technology Co. (NNVT) and 5,000 of dynode PMTs from Hamamatsu Photonics K. K.(HPK)
Production of hidden heavy-flavor mesons as open quantum systems (la présentation)
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Response characterization of a new radiochromic film to ultra high dose rates for light ions beams
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Tafel-analysis of the AP-CITROX decontamination technology of Inconel alloy 690
No full textInternational audienceSafe, effective, cost-effective, easy feasible and low-waste decontamination technologies are fundamental importance from environmental and radiation protection aspects. In this study the effectiveness of AP-CITROX decontamination technology of Inconel alloy 690 was investigated. Non-radioactive representative metal samples were formed to test of decontamination technology and the clear-, the corroded-, the decontaminated layer were analysed electrochemically. The results indicate that the passivation step of the technology was not completed. •Effectiveness of AP-CITROX decontamination technology of inconel alloy.•Oxide layer formation on inconel alloys.•Corrosion properties of inconel alloys
Sc production with proton beams on isotopically enriched Ti and Ti targets
No full textInternational audienceThe theranostic emerging radionuclide Sc is under the spotlight of the scientific community due to its medically favorable decay characteristics (t =3.3492 d, E=159.381 keV, Eβ−, mean=162.0 keV) for both the diagnostic and treatment procedures. In the framework of the LaRAMED (LAboratory of RAdionuclides for MEDicine) program at INFN-LNL (National Institute of Nuclear Physics-Legnaro National Laboratories), the investigation of the possible Sc production routes using a 70 MeV proton beam is one of the goals of the REMIX (Research on Emerging Medical radIonuclides from the X-sections) project, funded by INFN for the years 2021-2023. Since the LARAMED bunkers are currently under completion, experiments are performed in collaboration with the GIP ARRONAX facility (Nantes, France), where a 70 MeV multi-particle cyclotron is operational. In this work, the cross-section measurements using enriched Ti targets are reported and the results presented in comparison to the previous literature data, when available. The Sc excitation functions are analyzed in relation to the contaminants’ ones since the co-produced radionuclides can affect the dose delivered to a patient. Sc cross-section curves are mainly taken into account since Sc cannot be chemically separated from Sc and its half-life (t=83.79 d) is longer than the Sc one (t=3.3492 d)
Discussions on liquid bismuth target use as an alternative for astatine-211 production
No full textInternational audienceAstatine-211 is an alpha emitter that has been identified as a good candidate for targeted alpha therapy. There is an increasing demand on this radionuclide. Very intense beam from linac being put in operation nowadays could be used to meet this demand. This document presents the design exploration of concepts of liquid bismuth targets dedicated to astatine-211 production. Three concepts are presented and analyzed: a capsule, a fluid loop and a windowless fluid loop. Structural and thermal sizing were performed using mechanical Finite Element models (ANSYS Workbench) and Computational Fluid Dynamic models (FLUENT). Production rates were assessed accordingly. Feasibility and expected performances are discussed in conclusion
Results of DTAS Campaign at IGISOL: Overview
No full textInternational audienceThe β decays of more than twenty fission fragments were measured in the first experiments with radioactive-ion beams employing the Decay Total Absorption γ-ray Spectrometer. In this work, we summarize the main results obtained so far from this experimental campaign carried out at the Ion Guide Isotope Separator On-Line facility. The advances introduced for these studies represent the state-of-the-art of our analysis methodology for segmented spectrometers
Smooth interpolation between thermal Born and LPM rates
No full textInternational audienceIn a weakly coupled ultrarelativistic plasma, 1 + n ↔ 2 + n scatterings, with n ≥ 0, need sometimes to be summed to all orders, in order to determine a leading-order interaction rate. To implement this “LPM resummation”, kinematic approximations are invoked. However, in cosmological settings, where the temperature changes by many orders of magnitude and both small and large momenta may play a role, such approximations are not always justified. We suggest a procedure to smoothly interpolate between LPM-resummed 1 + n ↔ 2 + n and Born-level 1 ↔ 2 results, rendering the outcome applicable to a broader range of masses and momenta. The procedure is illustrated for right-handed neutrino production from a Standard Model plasma, and dilepton production from a QCD plasma
Estimating motion between avian vertebrae by contact modeling of joint surfaces
No full textInternational audienceEstimating the motion between two bones is crucial for understanding their biomechanical function. The vertebral column is particularly challenging because the vertebrae articulate at more than one surface. This paper proposes a method to estimate 3D motion between two avian vertebrae, by bones surface reconstruction and contact modeling. The neck of birds was selected as a case study because it is a functionally highly versatile structure combining dexterity and strength. As such, it has great potential to serve as a source for bioinspired design, for robotic manipulators for instance. First, 3D models of the vertebrae are obtained by computed tomography (CT). Next, joint surfaces of contact are approximated with polynomial surfaces, and a system of equations derived from contact modeling between surfaces is established. A constrained optimization problem is defined in order to find the best position of the vertebrae for a set of given orientations in space. As a result, the possible intervertebral range of motion is estimate