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Evidence of radiation induced segregation clustering in binary ferritic model alloys
No full textInternational audienceThis study investigates the microstructural changes and hardening mechanisms in irradiated binary Fe-Mn and Fe-Ni model alloys using atom probe tomography (APT). Mn and Ni are key alloying elements in reactor pressure vessel (RPV) steels, enhancing hardenability and mechanical properties while increasing irradiation sensitivity. Neutron irradiation introduces point defects that lead to solute clustering, impacting the mechanical properties of the materials. APT analysis reveals and quantifies the formation of Mn and Ni clusters, which act as barriers to dislocation motion and contribute to irradiation hardening. This research isolates the individual behavior of Mn and Ni by studying undersaturated binary model alloys, providing detailed insights into the mechanisms of radiation-induced segregation and nanoscale solute clustering and these effect on hardenin
Cosmological neutrino mass: a frequentist overview in light of DESI
No full textInternational audienceWe derive constraints on the neutrino mass using a variety of recent cosmological datasets, including DESI BAO, the full-shape analysis of the DESI matter power spectrum and the one-dimensional power spectrum of the Lyman- forest (P1D) from eBOSS quasars as well as the cosmic microwave background (CMB). The constraints are obtained in the frequentist formalism by constructing profile likelihoods and applying the Feldman-Cousins prescription to compute confidence intervals. This method avoids potential prior and volume effects that may arise in a comparable Bayesian analysis. Parabolic fits to the profiles allow one to distinguish changes in the upper limits from variations in the constraining power of the different data combinations. We find that all profiles in the CDM model are cut off by the bound, meaning that the corresponding parabolas reach their minimum in the unphysical sector. The most stringent 95% C.L. upper limit is obtained by the combination of DESI DR2 BAO, Planck PR4 and CMB lensing at 53 meV, below the minimum of 59 meV set by the normal ordering. Extending CDM to non-zero curvature and CDM relaxes the constraints past 59 meV again, but only CDM exhibits profiles with a minimum at a positive value. Using a combination of DESI DR1 full-shape, BBN and eBOSS Lyman- P1D, we successfully constrain the neutrino mass independently of the CMB. This combination yields meV (95% C.L.). The addition of DESI full-shape or Lyman- P1D to CMB and DESI BAO results in small but noticeable improvement of the constraining power of the data. Lyman- free-streaming measurements especially improve the constraint. Since they are based on eBOSS data, this sets a promising precedent for upcoming DESI data
Comparative assessment of feature extraction for fast neutron spectra prediction with machine learning algorithms using a CVD diamond detector
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Simulation of irradiated hybrid planar pixels modules at fluences expected at HL-LHC
No full textInternational audienceSignal loss is the main limitation on tracking/vertexing performance due to radiation damage effect to hybrid pixel detectors when irradiated at fluences expected at High Luminosity LHC (HL-LHC). It is important to have reliable predictions on the charge collection performance after irradiation in order to predict operational voltage values and test tracking algorithms robustness. In this paper the validation of combined TCAD and Monte Carlo simulations of hybrid silicon planar pixels sensors will be presented. In particular different trapping models will be compared to identify the one giving the best predictions. Eventually predictions on the collected charge performance of planar pixels modules at HL-LHC will be discussed
GATE 10 Monte Carlo particle transport simulation: II. Architecture and innovations
No full textInternational audienceOver the past years, we have developed GATE version 10, a major re-implementation of the long-standing Geant4-based Monte Carlo application for particle and radiation transport simulation in medical physics. This release introduces many new features and significant improvements, most notably a Python-based user interface replacing the legacy static input files. The new functionality of GATE version 10 is described in the part 1 companion paper (Sarrutet al2025 arXiv:2507.09842). The development brought significant challenges. In this paper, we present the solutions that we have developed to overcome these challenges. In particular, we present a modular design that robustly manages the core components of a simulation: particle sources, geometry, physics processes, and data acquisition. The architecture consists of integrated C++ and Python codes. This framework allows for the precise, time-aware generation of primary particles, a critical requirement for accurately modeling positron emission tomography, radionuclide therapies, or prompt-gamma timing systems. We present how GATE 10 handles complex Geant4 physics settings while exposing a simple interface to the user. Furthermore, we describe the methodological solutions that facilitate the seamless integration of advanced physics models and variance reduction techniques. The architecture supports sophisticated scoring of physical quantities (such as Linear Energy Transfer and Relative Biological Effectiveness) and is designed for multithreaded execution. The new user interface allows researchers to script complex simulation workflows and directly couple external tools, such as artificial intelligence models for source generation or detector response. By detailing these architectural innovations, we demonstrate how GATE 10 provides a more powerful and flexible tool for research and innovation in medical physics. This paper is not intended to be a developer guide. Its purpose is to share with the research community in-depth explanations of our development effort that made the new GATE 10 possible
Ti and Ni-based BEOL CMOS-compatible P+-InGaAs ohmic contacts for the future of wireless communications
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Atmospheric Specifications for Infrasound Studies: 1. Operational Analyses
No full textInternational audienceOperational analysis products issued by weather services are needed for the Comprehensive Nuclear-Test-Ban Treaty's (CTBT) infrasound monitoring activities. They provide atmospheric specifications as high as 80 km altitude. They are used to feed propagation simulations designed to characterize sources of interest. Acoustic waveguides for long-range infrasound propagation form in the lower and middle atmosphere between approximately 10 and 110 km. Analysis products have biases in the stratosphere and above due to the decreasing amount of operational observations available for data assimilation systems. We investigate differences between two state-of-the-art analysis products, namely that of the Integrated Forecasting System, IFS, from the European Center for Medium-range Weather Forecast and that of the ICOsahedral Nonhydrostatic model, ICON, from the German Weather Service. We compare their differing predictions of acoustic waveguides across the International Monitoring System (IMS) of the CTBT. We demonstrate significant differences in prediction of waveguide strength in the equatorial region, related to different amplitudes of the westerly phase of the Semi-Annual Oscillation. Waveguide occurrence predictions can differ by up to 40% across the IMS, in the meridional and zonal directions. We quantify biases with respect to LiDAR wind and temperature observations at three sites. We demonstrate biases of up to 40% and 60% in terms of waveguide occurrence prediction for ICON and IFS, respectively, using the Institute for Atmospheric Physics's LiDAR simultaneous wind and temperature observations. We stress the added-value for more high-resolution measurements in the tropical region where operational products strongly disagree at altitudes that matter for infrasound propagation.Plain Language Summary Weather forecast products are issued daily and feed different operational activities relying on knowledge of the atmospheric state. Among those, the monitoring of the atmosphere with infrasound technology has been put in place to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To localize and characterize acoustic sources of interest, meteorological conditions from the surface to high altitudes (120 km) are needed. Indeed winds and temperatures up to ∼120 km height can affect the way acoustic waves propagate through atmospheric layers across large distances (up to 1,000 s of km) before being detected at infrasound stations of the International Monitoring System (IMS). Two state-of-the-art meteorological products are compared with respect to their prediction of acoustic waveguides. They are respectively issued by the European Center for Medium-range Weather Forecast (ECMWF) and by the German Weather Service (DWD). We find notable difference across the IMS and more specifically in equatorial regions in the upper stratosphere where the Semi-Annual Oscillation's amplitude differs between products. We also compare the products with ground-based LiDAR observations, allow scanning of the vertical atmospheric structure at three sites to identify notable differences. This further supports the importance of using measurements to help improve and validate these high-resolution models.</div
Addendum to multiplicities of charged pions, kaons and unidentified charged hadrons on an isoscalar target measured by COMPASS Collaboration
No full textInternational audienceThe COMPASS Collaboration has recently published an article "Multiplicities of positive and negative pions, kaons, and unidentified hadrons from deep-inelastic scattering of muons off a liquid hydrogen target", Phys. Rev. D 112 (2025) 012002. In contrast to earlier COMPASS publications on similar topics, the aforementioned article features an enhanced treatment of QED radiative corrections, employing the DJANGOH Monte Carlo generator. This methodological improvement led to corrections that are up to 12% larger in the low-x, high-z region compared to the previously applied ones. To ensure consistent treatment of COMPASS data sets obtained using both isoscalar and proton targets, this paper presents an updated set of isoscalar multiplicities based on DJANGOH-derived radiative corrections. The present results supersede those published in Phys. Lett. B 764 (2017) 1 and Phys. Lett. B 767 (2017) 133
Positivity with Long-Range Interactions
No full textInternational audienceWe introduce infrared finite, analytic, crossing symmetric, Regge behaved, and Lorentz invariant amplitudes , labeled by the experimental energy resolution for detecting soft photons and gravitons. For exponentially smaller than any hard scale, they also satisfy unitarity and their associated cross sections reproduce the inclusive, infrared-finite cross sections of ordinary amplitudes. These properties make suitable for deriving infrared-safe positivity bounds on effective field theories in the presence of long-range forces even in . As an illustration, we present explicit bounds in the low-energy theory of pions coupled to electromagnetism and gravity
Generation and modulation of fully circularly polarized ultrabroadband THz radiation using two-color gas plasma techniques
No full textInternational audienceTerahertz optics enables powerful spectroscopy and imaging thanks to its non-ionizing nature and sensitivity to molecular and material properties. It is also beneficial to next-generation communications, since it offers vast bandwidth for ultra-fast, low-latency data transfer. Polarization control of terahertz waves is vital for applications in chiral spectroscopy, spin dynamics, ultrafast material studies, and communication multiplexing. Despite progress, full polarization control—particularly for ultra-broadband terahertz pulses—remains a challenge. In this work, we introduce a simple method for generating circularly polarized terahertz radiation with an ellipticity of 0.99. By optimizing key parameters—BBO crystal tilt, rotation, position, and pump chirp—we achieve broadband circular polarization across 30 THz, with indications of further extent to 40 THz. This approach advances fundamental studies in terahertz optics and paves the way for adaptive sensing and next-generation terahertz communications