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Experimental cross sections and production feasibility of Cu via Co(<math altimg="si153.svg" display="inline" id="d1e2317"><mi>α</mi></math>, 2n) for PET imaging using medium-energy alpha beams
No full textInternational audienceThe radionuclide 61Cu is a promising positron emitter for PET imaging. We investigated its production via the 59Co(α, 2n)61Cu reaction in the energy range 14–59 MeV using the stacked-foil technique. Excitation functions for 61Cu and co-produced radionuclides (60Cu, 56--58,60,61Co, 59Fe, 54Mn) were measured by HPGe γ-spectrometry and compared with TALYS 1.96 predictions and previous datasets. Thick Target Yields (TTY) and radionuclidic purity (RNP) were calculated for different irradiation conditions. Results show that high-yield and high-purity 61Cu production is achievable at 45 MeV on a 226μm thick Co target (TTYEOB≈ 840 MBq μA\protect \relax \special {t4ht=−}1, RNP >99.9% after 3 h irradiation and 3.4 h waiting time) and feasible with emerging 30 MeV α-accelerators using a 76μm thick Co target (TTYEOB≈ 420 MBq μA\protect \relax \special {t4ht=−}1, RNP > 99.9% after 3 h irradiation and 1.8 h waiting time). These findings support cost-effective production using inexpensive cobalt targets, reducing reliance on enriched materials. Practical implications for routine supply and synergy with α-accelerators designed for 211At are discussed. •The excitation function of the 59Co(α, 2n)61Cu reaction was measured up to 59 MeV.•Thick target yields and radionuclidic purity were evaluated for optimal 61Cu production.•Feasibility of 61Cu production using 30 MeV α-accelerators was explored
Integrating ethical, societal and environmental issues into algorithm design courses
No full textThis document, intended for computer science teachers, describes a case study that puts into practice a questioning of ethical, societal and environmental issues when designing or implementing a decision support system. This study is based on a very popular application, namely road navigation software that informs users of real-time traffic conditions and suggests routes between a starting point and a destination, taking these conditions into account (such as Waze). The approach proposes to intertwine technical considerations (optimal path algorithms, data needed for location, etc.) with a broader view of the ethical, environmental and societal issues raised by the tools studied. Based on the authors' experience conducting sessions with students over several years, this document discusses the context of such a study, suggests teaching resources for implementing it, describes ways to structure discussions, and shares scenarios in different teaching contexts
The High Voltage Splitter board for the JUNO SPMT system
No full textInternational audienceThe Jiangmen Underground Neutrino Observatory (JUNO) in southern China is designed to study neutrinos from nuclear reactors and natural sources to address fundamental questions in neutrino physics. Achieving its goals requires continuous operation over a 20-year period. The small photomultiplier tube (small PMT or SPMT) system is a subsystem within the experiment composed of 25600 3-inch PMTs and their associated readout electronics. The High Voltage Splitter (HVS) is the first board on the readout chain of the SPMT system and services the PMTs by providing high voltage for biasing and by decoupling the generated physics signal from the high-voltage bias for readout, which is then fed to the front-end board. The necessity to handle high voltage, manage a large channel count, and operate stably for 20 years imposes significant constraints on the physical design of the HVS. This paper serves as a comprehensive documentation of the HVS board: its role in the SPMT readout system, the challenges in its design, performance and reliability metrics, and the methods employed for production and quality control
Cross section measurements and production of 165Tm via the 165Ho(α,4n) reaction: generator of a pure Auger electron emitter, 165Er
No full textInternational audienceFor the treatment of micrometastatic or disseminated cancers, radiopharmaceuticals with high Linear Energy Transfert (LET) radiations, such as Auger Electron emitters (AEs), show potential in preclinical studies [Kassis, 2003]. Fundamental radiation biology studies on effects of AEs require a pure AE-emitting radionuclide, with minimal associated medium/high energy electron or photon emissions. To this end, 165Er is a promising radionuclide. It emits 7 AEs per decay [ICRP 107] with only associated X-rays emission. There are several possible production routes among which one of the most promising routes is the indirect production through 165Ho(α,4n)165Tm reaction that allows to make a 165Tm/165Er generator (T1/2 = 30.06 h/10.36 h). Moreover, the naturally monoisotopic target allows to limit co-productions by adapting beam energy. From that, it makes possible to reach better Molar Activity (MA) mandatory for dosimetry studies.In a project including also aspects of chemical separations and radiolabeling tests, a focus on productions with the 165Ho(α,x) reactions using a 68 MeV alpha beam from the GIP ARRONAX C70 XP cyclotron will be presented. Firstly, cross-sections measurements were performed using the stacked foil technique to consolidate the shape of the excitation function, which could show some discrepancies between existing values. Beam intensity has been obtained using an instrumented Faraday cup. Absolute cross-sections were also measured for the monitor reactions natAl(α,x)22Na,24Na. These values acquired between 38 and 67 MeV allow us to establish theoretical estimations of MA values under thick-target irradiation conditions. In a second phase, thick target (50 µm) production were carried out.The cross-section measurements performed for the 165Ho(a,xn) reactions are in agreement with recent cross-section data. The maximum production cross-section of 165Tm is around 1200 mb at 50 MeV. Thick target (50 µm) productions were carried out at an incident energy of 58 MeV, limiting the production of 166Tm and enhancing the 166Er/165Er ratio. The 165Tm activities produced for 14 µA.h are 93 MBq. A theoretical calculation based on these measured cross-section values gives a production of 125 MBq. This difference of 25% can be explained by the overestimation of the current measurement of our high-intensity irradiation device and by the losses of the recoil nuclei. Without considering the efficiency of chemical separation, the radiological purity of 165Er would be 100%. After a chemical separation to isolate the thulium completed End Of Beam (EOB) plus 2h and an 8h 165Tm/165Er generator cycle, the calculated MA is minimum for the 1st elution (EOB+10h) with 1.9 103 MBq/nmol for 50 MeV and 2.4 103 MBq/nmol for 56 MeV
Production of and hyperons in high-multiplicity proton-proton collisions at = 13 TeV
No full textInternational audienceThis paper presents the first measurements of and hyperon yields at the highest multiplicities reached in pp collisions at TeV. This measurement exploits the high-multiplicity pp collisions collected by ALICE with dedicated triggers. The selected collisions are characterised by about 30 charged particles per unit of rapidity, over four times more than in minimum-bias pp collisions at the same centre-of-mass energy, and about twice as many as in minimum-bias p-Pb or very peripheral Pb-Pb collisions at similar energies. The production yields and average transverse momenta of the hyperons agree with trends indicated by previous measurements in pp collisions at lower multiplicities. The difference in average transverse momenta between pp and p-Pb collisions, observed with the new high-multiplicity pp data, provides additional insight into the underlying particle production mechanisms in small systems. The results support a strong correlation between multi-strange hadron production and final-state multiplicity regardless of the collision system at the LHC energies, extending this observation to the highest multiplicity reached in pp collisions. The comparison with several state-of-the-art models (Pythia8.2 with the Monash 2013 tune, Pythia8.2 with Ropes, and EPOS4) suggests that the description of strange-hadron production is improved by recently introduced features such as interactions between overlapping strings in Pythia8.2 with Ropes and the collective expansion of high-density string regions in EPOS4
Measurement of the elliptic flow of He and H in Pb-Pb collisions at TeV
No full textInternational audienceThe first measurement of the elliptic flow coefficient of (anti)H and the study of the of measured in Pb-Pb collisions at TeV with the ALICE detector are presented. Based on the large data sample of approximately five billion events collected in 2023 during the LHC Run 3 data taking, these measurements provide important insights into the production mechanism of (anti)(hyper)nuclei, as well as into the phase-space distributions of nucleons and hyperons produced in heavy-ion collisions. The results are discussed in the context of hydrodynamic and coalescence models, highlighting how the measurement of the elliptic flow of nuclei, such as helium and hypertriton, provides critical constraints on hadronization models
Load-dependent travel time estimation for cargo bike routing in urban courier operations
No full textInternational audienceThis work addresses an extension of the pickup-and-delivery problem with time windows for urban courier companies using cargo bikes. The focus is on the impact of load weight on travel times, especially on routes with varying slopes, which significantly affect cyclists' speeds. The goal is to model and integrate these load-dependent travel time variations into a Small and Large Neighborhood Search (SLNS) algorithm. Building on the model of Fontaine (2022), this study proposes a new load-dependent travel time estimation model: the Slope Discretization Model (SDM). The SDM enables constant-time travel time calculations for paths with multiple slope segments, without assuming a fixed load. The model is based on the observation that, while travel time is not linear with respect to load, the reduction in speed relative to the bike's maximum speed (25 km/h) is linear. This allows for constant-time computation of travel times for any load on a segment, and discretization of slopes extends this to entire paths with high accuracy.The Load-Dependent PDPTW (LD-PDPTW) is defined to model cargo bike delivery operations, accounting for load variations due to pickups and deliveries. To solve LD-PDPTW, a SLNS metaheuristic is developed, featuring vehicle minimization, state-of-the-art operators, and a feasibility test adapted to the SDM. New benchmark instances, based on open-source geographic data and real altitude variations from Nantes, France, are introduced. Results show that the SDM drastically reduces computation times compared to previous models while maintaining the same accuracy. The SLNS algorithm provides competitive solutions on standard benchmarks and effectively integrates load dependency.This project received funding from the European Union's Horizon Europe research and innovation programme under grant agreement No 101069806 (DECARBOMILE)
Deception Detected: An Empirical Study of SSH Honeypot Detection and Fingerprinting in a Capture-the-Flag Competition
No full textThe effectiveness of cyber deception technologies relies on their ability to remain indistinguishable from production systems under adversarial scrutiny. Consequently, this paper presents an empirical study of SSH honeypot detection techniques observed during a high-interaction honeypot challenge deployed in the qualification phase of the European Cyber Week (ECW) Capture-the-Flag (CTF) competition. The challenge was designed to log and analyze the methods used by hackers to distinguish a simulated SSH service from a genuine operational environment. We analyze a dataset of adversarial fingerprinting behaviors, including protocol-level, behavioral, and environmental indicators used for honeypot identification. Based on observed attacker actions, we derive a taxonomy of effective SSH honeypot detection vectors. The results highlight practical weaknesses in deployed deception systems and provide actionable insights for improving the realism, robustness, and operational management of SSH honeypots. These findings support the design of more resilient deception infrastructures and contribute to measurement-based network security and threat intelligence practices
Network Abstraction with Provisioning Guarantees for Multi-Domain Virtual Network Embedding
No full textInternational audienceNetwork Function Virtualization and Software Defined Network have opened the way to network resources as market commodities.However, establishing slices over several Infrastructure Providers (InPs) implies a multi-domain approach and requires confidentiality. In particular, InPs are reluctant to expose their network topology and amount of resources (bandwidth and delay). We devise BLEND, a method that allows providers to construct an abstraction of their network and share a partial view of their resources while maintaining a high degree of confidentiality. Brokers can then aggregate these abstractions to solve the Multi-domain Virtual Network Embedding problem to embed slices with no back-and-forth between them and providers. Moreover, BLEND offers a way for the providers to generate abstractions with different amount of trade-off between delay and bandwidth constraints. We show on realistic and synthetic graphs that BLEND's parameterized approach is crucial as no universal value of maximizes the service acceptance rate of heterogeneous requests.</p
