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Status of Design of the First Wall Supports of the Divertor Tokamak Test Facility
No full textThis article describes the solutions investigated for the design of the support and fixation systems of the first wall (FW) to the vacuum vessel (VV) at both inboard and outboard sides, in order to define their engineering design in compliance with the other involved systems of the divertor tokamak test (DTT) facility: VV, diagnostics, remote handling (RH), and plasma physics. The aim is to engineer them to cope with the electromagnetic (EM) loads resulting from disruption events (VDE and MD) or from discharges occurring in the coils (i.e., toroidal field coils fast discharge)
High-resolution cross section measurements for neutron interactions on 89 Y with incident neutron energies up to 95 keV
No full textThe cross section of the 89 Y(n, γ) reaction has important implications in nuclear astrophysics and for advanced nuclear technology. Given its neutron magic number N = 50 and a consequent small neutron capture cross section, 89 Y represents one of the key nuclides for the stellar s-process. It acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier elements. Moreover, it is located at the overlapping region, where both the weak and main s-process components take place. 89 Y, the only stable yttrium isotope, is also used in innovative nuclear reactors. Neutron capture and transmission measurements were performed at the time-of-flight facilities n_TOF at CERN and GELINA at JRC-Geel. Resonance parameters of individual resonances were extracted from a resonance analysis of the experimental transmission and capture yields, up to a neutron incident energy of 95 keV. Even though a comparison with results reported in the literature shows differences in resonance parameters, the present data are consistent with the Maxwellian averaged cross section suggested by the astrophysical database KADoNiS
In-Depth Analysis and Characterization of a Hazelnut Agro-Industrial Context through the Integration of Multi-Source Satellite Data: A Case Study in the Province of Viterbo, Italy
Full text linkThe production of “Nocciola Romana” hazelnuts in the province of Viterbo, Italy, has evolved into a highly efficient and profitable agro-industrial system. Our approach is based on a hierarchical framework utilizing aggregated data from multiple temporal data and sources, offering valuable insights into the spatial, temporal, and phenological distributions of hazelnut crops To achieve our goal, we harnessed the power of Google Earth Engine and utilized collections of satellite images from Sentinel-2 and Sentinel-1. By creating a dense stack of multi-temporal images, we precisely mapped hazelnut groves in the area. During the testing phase of our model pipeline, we achieved an F1-score of 99% by employing a Hierarchical Random Forest algorithm and conducting intensive sampling using high-resolution satellite imagery. Additionally, we employed a clustering process to further characterize the identified areas. Through this clustering process, we unveiled distinct regions exhibiting diverse spatial, spectral, and temporal responses. We successfully delineated the actual extent of hazelnut cultivation, totaling 22,780 hectares, in close accordance with national statistics, which reported 23,900 hectares in total and 21,700 hectares in production for the year 2022. In particular, we identified three distinct geographic distribution patterns of hazelnut orchards in the province of Viterbo, confined within the PDO (Protected Designation of Origin)-designated region. The methodology pursued, using three years of aggregate data and one for SAR with a spectral separation clustering hierarchical approach, has effectively allowed the identification of the specific perennial crop, enabling a deeper characterization of various aspects influenced by diverse environmental configurations and agronomic practices.The accurate mapping and characterization of hazelnut crops open opportunities for implementing precision agriculture strategies, thereby promoting sustainability and maximizing yields in this thriving agro-industrial system
Detection of morphological and eco-physiological traits of ornamental woody species to assess their potential Net O3 uptake
Full text linkUrban greening can improve cities' air quality by filtering the main gaseous pollutants such as tropospheric ozone (O3). However, the pollutant removal capacity offered by woody species strongly depends on eco-physiological and morphological traits. Woody species with higher stomatal conductance (gs) can remove more gases from the atmosphere, but other species can worsen air quality due to high O3 forming potential (OFP), based on their emitting rates of biogenic volatile organic compounds (bVOCs) and Leaf Mass per Area (LMA). Presently, there is a lack of data on eco-physiological (gs, bVOCs emissions) and foliar traits (LMA) for several ornamental species used in urban greening programs, which does not allow assessment of their O3 removal capacity and OFP. This study aimed to (i) parameterize gs, assess bVOCs emissions and LMA of 14 ornamental woody species commonly used in Mediterranean urban greening, and (ii) model their Net O3 uptake. The gs Jarvis model was parameterized considering various environmental conditions alongside isoprene and monoterpene foliar bVOCs emission rates trapped in the field and quantified by gas chromatography-mass spectrometry. The results are helpful for urban planning and landscaping; suggesting that Catalpa bignonioides and Gleditsia triacanthos have excellent O3 removal capacity due to their high maximum gs (gmax) equal to 0.657 and 0.597 mol H2O m−2 s−1. Regarding bVOCs, high isoprene (16.75 μg gdw−1 h−1) and monoterpene (13.12 μg gdw−1 h−1) emission rates were found for Rhamnus alaternus and Cornus mas. In contrast, no bVOCs emissions were detected for Camellia sasanqua and Paulownia tomentosa. In conclusion, 11 species showed a positive Net O3 uptake, while the use of large numbers of R. alaternus, C. mas, and Chamaerops humilis for urban afforestation planning are not recommended due to their potential to induce a deterioration of outdoor air quality
Radioisotope production using lasers: From basic science to applications
Full text linkThe discovery of chirped pulse amplification has led to great improvements in laser technology, enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers. Protons with energies of tens of MeV can be accelerated using, for instance, target normal sheath acceleration and focused on secondary targets. Under such conditions, nuclear reactions can occur, with the production of radioisotopes suitable for medical application. The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators. In this paper, we study the production of 67Cu, 63Zn, 18F, and 11C, which are currently used in positron emission tomography and other applications. At the same time, we study the reactions 10B(p,α)7Be and 70Zn(p,4n)67Ga to put further constraints on the proton distributions at different angles, as well as the reaction 11B(p,α)8Be relevant for energy production. The experiment was performed at the 1 PW laser facility at Vega III in Salamanca, Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a high purity germanium detector. Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera [Nucl. Instrum. Methods Phys. Res., Sect. A 637, 164-170 (2011)]
LIBS as diagnostics of analytical chemistry for surface mapping of complex mixed samples simulating debris inside the TEPCO's Fukushima Daiichi Nuclear Power Plant (FDNPS) reactor cores
Get PDFThe Nuclear Energy Agency (NEA) launched the Nuclear Education, Skills and Technology (NEST) Framework to pursue careers in the nuclear field, by exposing researcher working on these topics to international challenging project of real-world issue and by transferring the knowledge and expertise accumulated in the current generation to them through hands-on training. In this framework the 2022 edition of the NEST project offered a training educational period at the Collaborative Laboratories for Advanced Decommissioning (CLADS) located at Tomioka, Futaba District, in the Fukushima prefecture (Japan). Among the research sectors active at CLADS there is the application and development of the LIBS technique as diagnostics of analytical chemistry aiming at characterizing the debris inside the Tokyo Electric Power Company (TEPCO)’s FDNPS reactor cores after the tsunami of March 2011, which destroyed three of the six reactors of the plant. These debris need to be chemically characterized with techniques suitable to be implemented in compact, remote and radiation resistant devices, due to the residual radioactivity of the cores. The present study shows the results in realizing chemical bi-dimensional maps of samples in the form of compressed tablets of mixed oxides, with a complex distribution and concentration of chemicals simulating these debris. The results allowed to create detailed maps of the samples, with spatial resolution down to 0.5 mm and an excellent correspondence between the real spatial distribution of the materials and that reconstructed by LIBS. Moreover, it was found a good correspondence between the nominal concentration of the chemicals and the concentration estimated by using LIBS. This study shows the potentialities of LIBS in the realization of chemical maps on samples of interest for FDNPS, providing multi-elemental images of the samples under analysis
Future of 99Mo reactor-independent supply
No full textMolybdenum-99 is essential for nuclear medicine, being the parent radionuclide of 99mTc, which is commonly used in single-photon-emission computed tomography scans. Worldwide, the supply of 99Mo has faced considerable disruption twice in recent years: in 2009 triggered by the unexpected simultaneous shutdown of two nuclear research reactors, and in 2020 because of disruption to shipments of 99Mo as a consequence of severe restrictions on flights. This Perspective therefore examines alternative means of 99Mo production, via cyclotrons, electron linear accelerators and fusion neutron sources. The research and development of methods for 99Mo that can be synergic and complementary to reactors in the short-to-medium term and alternative to them in the long term is strategic for addressing potential global events that might produce reduced access to healthcare procedures relying on diagnostic as well as therapeutic radionuclides
Evolution of Coastal Environments under Inundation Scenarios Using an Oceanographic Model and Remote Sensing Data
No full textA new methodology to map Italian coastal areas at risk of flooding is presented. This approach relies on detailed projections of the future sea level from a high-resolution, three-dimensional model of the Mediterranean Sea circulation, on the best available digital terrain model of the Italian coasts, and on the most advanced satellite-derived data of ground motion, provided by the European Ground Motion Service of Copernicus. To obtain a reliable understanding of coastal evolution, future sea level projections and estimates of the future vertical ground motion based on the currently available data were combined and spread over the digital terrain model, using a GIS-based approach specifically developed for this work. The coastal plains of Piombino-Follonica and Marina di Campo (Tuscany Region), Alghero-Fertilia (Sardinia), and Rome and Latina-Sabaudia (Lazio Region) were selected as test cases for the new approach. These coastal stretches are important for the ecosystems and the economic activities they host and are relatively stable areas from a geological point of view. Flood maps were constructed for these areas, for the reference periods 2010–2040, 2040–2070, and 2040–2099. Where possible, the new maps were compared with previous results, highlighting differences that are mainly due to the more refined and resolved sea-level projection and to the detailed Copernicus ground motion data. Coastal flooding was simulated by using the “bathtub” approach without considering the morphodynamic processes induced by waves and currents during the inundation process. The inundation zone was represented by the water level raised on a coastal DTM, selecting all vulnerable areas that were below the predicted new water level. Consequent risk was related to the exposed asset
Realizzazione di un dispositivo elettronico per l'interfacciamento di sensori elettrochimici di gas per il monitoraggio della qualità dell'aria
Full text linkNegli ultimi anni, l’emergere di nuove tecnologie per la misurazione delle concentrazione dei gas in ambiente ha introdotto nuovi dispositivi a basso costo disponibili sul mercato. Il loro funzionamento è basato su svariati tipi di sensori caratterizzati da diverse tecnologie che ne determinano il costo finale, ma anche le loro prestazioni. Tra questi, i più promettenti e i più studiati risultano essere senza dubbio i sensori di tipo elettrochimico utilizzati per il monitoraggio della qualità dell’aria, ad integrazione degli strumenti più tradizionali, quali gli analizzatori chimici. Tra i costruttori di tali tipi di sensori operanti a livello globale, la Alphasense si contraddistingue per la sua offerta di prodotti caratterizzati da un interessante rapporto qualità/prezzo. Un filone delle attività del laboratorio “test sensori”, sito nel centro ricerche Enea di Brindisi, si è quindi focalizzato nello studio delle prestazioni di tali sensori e dei loro possibili campi applicativi. A tal fine, un dispositivo elettronico per l’interfacciamento e il corretto utilizzo dei suddetti sensori, è stato progettato e realizzato nei nostri laboratori. Esso offre una serie di funzionalità e caratteristiche aggiuntive rispetto al corrispettivo fornito dal produttore dei sensori oggetto di studio, conferendogli una maggiore flessibilità ed adattabilità all’ “hardware” già sviluppato e in dotazione al nostro laboratorio.In recent years, new emerging technologies for the measurement of gas concentrations provided new low-cost devices available on the global market. Their operation is based on various types of sensors characterized by various technologies influencing their costs and their performance quality. Without any doubt, the most promising and the most studied sensors are the electrochemical ones, which are used also for the air quality monitoring to complement the data provided by the traditional instrumentation, such as, the chemical analyzers. Among the manufacturers of such kind of sensors operating worldwide, the Alphasense brand is featured by its capability to offer products having an interesting quality-price ratio. A branch of the activities characterizing the “Sensor Test Lab”, located in the Enea research center of Brindisi, is focused in the study of the performance quality of such sensors and their possible use areas. To this purpose, an electronic device for interfacing and correctly operating these sensors has been designed and implemented in our laboratories. It can offer several additional functionalities compared with the similar device provided by the manufacturer of the sensors considered for our studies. The new functionalities implemented in the device presented in this document give it more flexibility and adaptability to the “hardware” previously developed in our laboratory
Roles of ECH system in DTT plasma operations
Full text linkThe Divertor Tokamak Test (DTT) facility is equipped with auxiliary heating systems in order to be able to load the divertor with a power flux relevant to study the power exhaust issue in a reactor relevant range of parameter. The powerful system is the Electron Cyclotron Heating (ECH) with an installed power of 32 MW in its largest extension. Together with the bulk heating of the DTT plasma, the ECH system will cover several tasks for the plasma operation. This paper summarizes the main characteristics and design choices of the DTT ECH system and the related physics studies, based on the reference DTT plasma, to develop and control the plasma, fulfilling the functional tasks, with the support of simulation activities. Dedicated studies have been carried out to investigate the capability of EC power to assist plasma start-up, stabilize MHD activity and support current ramp up/down. In addition, it has been studied how changes of the ECH power distribution can have an impact on the plasma profiles, affecting the fueling pellet effectiveness and MHD modes