Software for the next generation of experiments at the Future Circular Collider (FCC), should by design efficiently exploit the available computing resources and therefore support of parallel ...execution is a particular requirement. The simulation package of the FCC Common Software Framework (FCCSW) makes use of the Gaudi parallel data processing framework and external packages commonly used in HEP simulation, including the Geant4 simulation toolkit and the DD4HEP geometry toolkit. Using Geant4 for full simulation implies taking into account all physics processes for transporting the particles through detector material and this is highly CPU-intensive. At the early stage of detector design and for some physics studies such accuracy is not needed, making a fast parametrised simulation better suited. Geant4 provides the tools to define a parametrisation, where the overall response of the detector is simulated in a parametric way. Many experiments create their own frameworks for these fast simulation studies. The implementation for the FCC allows an interplay between the two types of simulation within Geant4. Based on the type of the particle or a region within the detector, either full or fast simulation may be performed, running the time-consuming detailed simulation only for the regions and particles of interest.
The physics reach and feasibility of the Future Circular Collider are currently under investigation. The goal is to collide protons with centre-of-mass energies up to 100 TeV, extending the research ...carried out at the current HEP facilities. The detectors designed for the FCC experiments need to tackle harsh conditions of the unprecedented collision energy and luminosity. The baseline technology for the calorimeter system of the FCC-hh detector is described. The electromagnetic calorimeter in the barrel, as well as the electromagnetic and hadronic calorimeters in the endcaps and the forward regions, are based on the liquid argon as active material. The detector layout in the barrel region combines the concept of a high granularity calorimeter with precise energy measurements. The calorimeters have to meet the requirements of high radiation hardness and must be able to deal with a very high number of collisions per bunch crossings (pile-up). A very good energy and angular resolution for a wide range of electrons' and photons' momentum is needed in order to meet the demands based on the physics benchmarks. First results of the performance studies with the new liquid argon calorimeter are presented, meeting the energy resolution goal.
In this study structural and mechanical properties of a 1 μm thick Al2O3 coating, deposited on 316L stainless steel by Pulsed Laser Deposition (PLD), subjected to high energy ion irradiation were ...assessed. Mechanical properties of pristine and ion-modified specimens were investigated using the nanoindentation technique. A comprehensive characterization combining Transmission Electron Microscopy and Grazing-Incidence X-ray Diffraction provided deep insight into the structure of the tested material at the nano- and micro-scale. Variation in the local atomic ordering of the irradiated zone at different doses was investigated using a reduced distribution function analysis obtained from electron diffraction data. Findings from nanoindentation measurements revealed a slight reduction in hardness of all irradiated layers. At the same time TEM examination indicated that the irradiated layer remained amorphous over the whole dpa range. No evidence of crystallization, void formation or element segregation was observed up to the highest implanted dose. Reported mechanical and structural findings were critically compared with each other pointing to the conclusion that under given irradiation conditions, over the whole range of doses used, alumina coatings exhibit excellent radiation resistance. Obtained data strongly suggest that investigated material may be considered as a promising candidate for next-generation nuclear reactors, especially LFR-type, where high corrosion protection is one of the highest prerogatives to be met.
•The current state of knowledge on PLD-grown Al2O3 coatings was reviewed.•PLD-grown amorphous Al2O3 coatings were irradiated with 250 keV and 1.2 MeV Au ions.•Influence of irradiations on mechanical ...properties was studied via nanoindentation.•The coating exhibit excellent room temperature radiation resistance.•Qualitative data obtained in low and high energy experiment are consistent.
It is well known that ion irradiation can be successfully used to reproduce microstructural features triggered by neutron irradiation. Even though the irradiation process brings many benefits, it is also associated with several drawbacks. For example, the penetration depth of the ion in the material is very limited. This is particularly important for energies below MeV, ultimately reducing the number of available irradiation facilities. In addition to that, extracting information exclusively from the modified volume may be challenging. Therefore, extreme caution must be taken when interpreting obtained data. Our work aims to compare the findings of nanomechanical studies already conducted separately on thin amorphous ceramic coatings irradiated with ions of different energies, hence layers of different thicknesses. In this work, we show that in some instances, the 10% rule may be obeyed. In order to prove our finding, we compared results obtained for ion irradiated (with two energies: 0.25 and 1.2 MeV up to 25dpa) alumina coating system. Mechanical properties of pristine and ion-irradiated specimens were studied by nanoindentation technique. Interestingly, the qualitative relationship between nanohardness and irradiation damage level is very similar, regardless of the energy used. The presented work proves that for some materials (e.g., hard coatings), the qualitative assessment of the mechanical changes using nanoindentation might be feasible even for shallow implantation depths.
This study investigates the effect of Nb concentration on the mechanical properties, superelasticity, as well as deformation behavior of metastable
β
-phase Ti–Nb alloys produced via powder ...metallurgy. The alloys were fabricated through mechanical alloying, followed by consolidation using hot pressing. The resulting microstructure comprises fine
β
-phase grains with TiC carbide precipitates at the grain boundaries. The study reveals non-linear variations in the values of yield strength for the manufactured materials, which were attributed to the occurrence of various deformation mechanisms activated during the loading. It was found that the mechanisms change with the increasing concentration of Nb in the manner: stress-induced martensitic transformation, twinning, slip. However, all these mechanisms were activated at a reduced concentration of Nb compared to the materials obtained by casting technology previously reported in the literature. This is most probably associated with the elevated oxygen content, which affects the stability of the parent
β
-phase. The study revealed that superelasticity in Ti–Nb-based alloys prepared using powder metallurgy may be achieved by reducing the content of
β
-stabilizing elements compared to alloys obtained by conventional technologies. In this study, the Ti–14Nb (at. pct) alloy exhibited the best superelasticity, whereas conventionally fabricated Ti–Nb alloys displayed superelasticity at an Nb concentration of approximately 26 at. pct. The developed material exhibited a non-conventional, one-stage yielding behavior, resulting in a superelastic response at significantly higher stresses compared to conventionally fabricated Ti–Nb alloys.
In terms of nuclear applications, ceramics are seen as a particularly promising class of materials due to their chemical inertness and relatively high radiation resistance. However, since ceramics ...exhibit high brittleness at low homologous temperatures, the application of monolithic ceramics as structural components of nuclear power plants is rather limited. On the other hand, deposition of ceramic coatings on a metallic substrate may result in an excellent combination of mechanical, corrosion and radiation properties (especially at high temperature). In this work, Al2O3 coatings deposited by Pulsed Laser Deposition (PLD) on 316L SS substrate at room temperature were investigated. In order to simulate the influence of neutrons, alumina-coated and 316L SS samples were irradiated at room temperature with 250 keV Au+ and 150 keV Fe2+ ions, respectively. The influence of ion irradiation on nanomechanical properties of the studied materials was investigated by means of Nanoindentation (NI) technique. Based on the obtained results, nanomechanical properties as a function of radiation damage level were determined and linked to the results of Grazing Incidence X-Ray Diffraction (GIXRD) analysis and other structural data available in the literature. Irradiation-induced softening and hardening were observed, respectively, in the alumina coating and 316L SS. Reported differences, which are induced by the irradiation effects, are considered to be due to the different microstructures of the pristine materials.
•The hardness of the alumina coating drops and reaches maximum level upon which it increases and saturates for the high dpa•The hardness of 316L SS increases rapidly up to 3 dpa, and tends to saturate once this limit is achieved•Reported differences induced by the irradiation effects are considered to be due to the different microstructural features
Contrasting with the situation found in birds and mammals, sex chromosomes are generally homomorphic in poikilothermic vertebrates. This homomorphy was recently shown to result from occasional X-Y ...recombinations (not from turnovers) in several European species of tree frogs (Hyla arborea, H. intermedia and H. molleri). Because of recombination, however, alleles at sex-linked loci were rarely diagnostic at the population level; support for sex linkage had to rely on multilocus associations, combined with occasional sex differences in allelic frequencies. Here, we use direct evidence, obtained from anatomical and histological analyses of offspring with known pedigrees, to show that the Eastern tree frog (H. orientalis) shares the same pair of sex chromosomes, with identical patterns of male heterogamety and complete absence of X-Y recombination in males. Conservation of an ancestral pair of sex chromosomes, regularly rejuvenated via occasional X-Y recombination, seems thus a widespread pattern among Hyla species. Sibship analyses also identified discrepancies between genotypic and phenotypic sex among offspring, associated with abnormal gonadal development, suggesting a role for sexually antagonistic genes on the sex chromosomes.
Nickel-based superalloys display outstanding properties such as excellent creep strength, remarkable fracture toughness parameters, and corrosion resistance. For this reason, Ni-based materials are ...considered as materials dedicated to the IV generation of nuclear reactors. Although these materials seem promising candidates, their radiation resistance and impact of radiation damage on the deformation mechanism are still not fully understood. In this work, two commercially available nickel-based alloys (Hastelloy X and Haynes 230) were investigated. Structural and mechanical properties have been described by means of SEM/EBSD, TEM, and nanoindentation tests. Radiation damage has been performed by Ar-ion with energy 320 keV with two doses up to 12dpa. Obtained results have revealed a hardening effect for both levels of damage. However, more intensive effects were observed for Hastelloy X. Moreover, a significant change in precipitates' morphology in Hastelloy X has been observed. It has been proposed that structural differences between both alloys determine the type of occurring radiation-induced processes. Excess energy deposited into materials' structure during ion-irradiation can lower the temperature of nucleation of high-temperature phases, which initiates the formation of grain boundary serrations.
•Two Ni-based superalloys were submitted to high temperature Ar+ irradiation.•Ion irradiation leads to significant hardening of both materials.•Ion irradiation promotes carbide morphology alteration in Hastelloy X.•Radiation-induced diffusion enhances early-stages of carbides transformation.•Structural features determine processes occurring during radiation-damaging.
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•ODS steels strengthened by three different oxides have been produced by MA and SPS.•Specimens have been exposed to high-energy Ar+ ion irradiation.•The strengthening particle type ...determines the structural features of the material.•ODS steels maintain similar irradiation resistance up to 1e15 ions/cm2 Ar-ion fluence.
One of the most promising candidates for constructing IV generation nuclear reactors is Oxide Dispersed Strengthening (ODS) Reduced Activation Ferritic (RAF) steel. It is known that introducing refractory oxides to the ferritic matrix makes it possible to obtain a brand-new kind of materials with an excellent set of properties. In the present work, the authors focused on verifying materials' structural and mechanical properties strengthened by three different types of refractory oxides submitted to ion-irradiation. Three materials with an elemental chemical composition of 12 %Cr, 2 %W, 0.3 %Ti, and strengthened with 0.3% Y2O3 or Al2O3 or ZrO2 were produced by mechanical alloying and subsequently consolidated by Spark Plasma Sintering technique. Manufactured materials have been submitted to high energy (500 keV) Ar-ion irradiation at room temperature with three fluences (up to 5x1015 ions/cm2). This procedure allowed to generate a thin, strongly damaged zone with approximate thickness of 230 nm. SEM/EBSD and TEM bservations, Grazing Incidence X-ray Diffraction analysis, and nanoindentation tests have been included in examination of modified layers. Implementation of these techniques allowed to reveal alteration of structural and mechanical features between unmodified material and radiation-affected layer. Obtained results showed a strong correlation between the strengthening oxide and materials' microstructural and mechanical behavior under radiation damage. It has been proved that below 1x1015 ions/cm2 mechanical properties in the modified layer of all materials are very similar. Reported behavior may be related to the efficient annealing of the radiation defect process. Above this limit, significant differences between the materials are visible. It is believed that described phenomenon is directly related to the presence of the structural features and their capacity to act as defect sinks. Consequently, type of dominant mechanisms occurring in modified layer is proposed.
Graphite is known as a material with excellent thermo-mechanical, structural and neutron moderation properties. It is currently used as a core structural component for High Temperature Gas Cooled ...Reactor (HTGR). It is due to the fact that graphite has been extensively tested and proved to satisfy most of HTGR operating requirements. However, one question still remain unclear. Graphite, depending from the manufacture method, type and purity shows different mechanical and structural properties. In addition to that, literature data is poor in comparative studies of current and used in the past materials. For this reason, series of tests involving Scanning Electron Microscopy, Raman Spectroscopy, X-ray diffraction and nanoindentation have been performed on the virgin samples of two types of nuclear graphite’s: IG-110 and nuclear graphite used in decommissioned EWA reactor. Obtained results clearly shows differences in microstructural and mechanical properties of both types of graphite’s. Reported changes have been discusses and attributed to the density of the material and its origin.
•Mechanical and structural properties measured at room temperature of two different graphite materials have been investigated.•IG110 presents a more uniform structure.•Both materials present turbostratic structure.
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