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2026 Articolo in rivista open access

Towards large databases analysis for reactors-relevant studies on high electron temperature measurement discrepancy

Senni L. ; Orsitto F. P. ; Giruzzi G. ; Mazon D. ; Mazzi S. ; Fontana M. ; Giovannozzi E. ; Kos D. ; Maslov M. ; Challis C. ; Frigione D. ; Garzotti L. ; Hobirk J. ; Kappatou A. ; Keeling D. ; Lerche E. ; Maggi C. ; Mailloux J. ; Rimini F. ; Van Eester D. ; contributors J.

Accurate electron temperature (Te) measurements are critical for future reactors such as ITER, CFETR, and DEMO, where core T e is expected to exceed 25 keV [1-3]. However, in current tokamaks, core electron temperature measurements become increasingly challenging at high values (typically above 6–7 keV), where discrepancies frequently arise between diagnostics such as Thomson Scattering (TS) and Electron cyclotron emission (ECE). These discrepancies highlight both a diagnostic challenge and an opportunity to deepen the understanding of core plasma physics. Recent studies have provided further insights into these phenomena, clarifying key physical aspects, and yielding more substantial results [4-8]. Nevertheless, a broader experimental database remains essential to validate and support the physical hypotheses developed in recent years. This contribution reports on preliminary results obtained from the analysis of the entire JET-DTE3 dataset, providing a status update on our ongoing research. Specifically, we focus on the methodological advancements and the analytical tools recently developed to manage the unprecedented volume of data within the DTE3 database. This framework enables a deep investigation into the T e discrepancy, marking the first time this phenomenon has been systematically studied across such an extensive and statistically significant dataset. This work is conducted within the framework of the International Tokamak Physics Activity (ITPA) JEX#17 on `High Electron Temperature Measurements', which aims to compare data collected across multiple fusion devices to systematically identify the origin of the observed Te discrepancy.

Analysis and statistical methods Data processing methods Nuclear instruments and methods for hot plasma diagnostics Plasma diagnostics - charged-particle spectroscopy
CNR IRIS
2026 Articolo in rivista restricted access

Thermal Assessment of the DTT Bolometric Camera

D'Agostino V. ; Belpane A. ; Peluso E. ; Palomba S. ; Murari A. ; Gabellieri L. ; Senni L. ; Apruzzese G. M. ; Gelfusa M.

The Divertor Tokamak Test facility (DTT) is a fusion device under construction at the ENEA Research Centre in Frascati, Italy. DTT’s primary mission is to explore and test the physics and technology of concepts for the exhaust of the plasma thermal power, especially in the divertor region, in support to ITER and DEMO design. From this perspective, careful control of the total radiation emission will be essential for the operation of these next generation devices. This work focuses on the DTT bolometry system, which is currently in the design phase. Commercial foil bolometers have been selected to provide line-integrated measurements and enable tomographic reconstructions at this stage. The mechanical layout and integration into the machine have been defined, and the line-of-sights (LoS) configuration has been validated. However, preliminary thermo-mechanical analyses have revealed that the initial design did not fully meet all specifications. To address this, an actively cooled protective housing has been included to withstand the high thermal loads from the plasma, approximately 0.5 MW/m2 for about 100 s in DTT. In this study, the equatorial bolometric camera simulations have been further refined, and the protective housing has been designed and fully integrated in the diagnostic port. A parametric thermal analysis has been performed, and the final design has been validated through finite elements simulations.

Bolometry Design Diagnostics DTT FEM
CNR IRIS
2025 Articolo in rivista metadata only access

Standardizing high electron temperature measurement comparisons: a method for cross-diagnostic and cross-machine analysis

L. Senni ; F. P. Orsitto ; M. Fontana ; S. Mazzi ; E. Giovannozzi ; G. Giruzzi

In tokamaks, measuring electron temperatures in the plasma core may be quite challenging, especially when they exceed 6-8 keV [1]. Discrepancies are detected between the values measured by different diagnostics, such as Thomson Scattering (TS) and Electron Cyclotron Emission (ECE), which are expected to agree. Accurate and reliable determination of electron temperature in high-temperature scenarios, is crucial for the development of future reactors like ITER and Demo (with ITER's core plasma expected to have an electron temperature of about 25 keV) [2], as well as for the Chinese Fusion Engineering Test Reactor (CFETR) [3]), in which discrepancies in electron temperature measurements could be even more pronounced. Resolving this diagnostic issue is crucial because it implies a deep understanding of important aspects of plasma physics in the core and beyond. Recently, further studies on this topic have yielded substantial results and clarified several aspects [9,10,11,12]. Current research focuses on the possible causes of the local non-Maxwellian shape of the electron energy distribution function, which is at the root of these discrepancies [1,4,5,6,7,8,9,10,11,12]. Ongoing research by various groups working on magnetic confinement machines worldwide aims to address this long-standing issue within the framework of an ITPA (International Tokamak Physics Activity) initiative. This paper proposes a method to compare data collected by ECE and TS, which is based upon previously developed techniques for analyzing JET data [1], and is implemented in a dedicated Python code, to tackle issues identified in recent years, while also ensuring the output is comparable across different machines. The goal is to perform comparisons under consistent conditions, irrespective of machine-specific factors such as dimensions, fields, and coordinates. The methods developed and the corresponding implementations in a code, addresses several critical aspects, including the positions of measurements, i.e. the plasma position relative to the diagnostics' lines of sight (LoS), the involved volumes, and other controls to ensure uniformity of results during multi-shot analyses. These controls encompass acquisition rate, data interpolation, and the equilibrium reconstruction codes employed, with the objective of obtaining the best possible comparison between the two diagnostics.

Data processing methods Nuclear instruments and methods for hot plasma diagnostics
CNR IRIS
2025 Articolo in rivista open access

Effects of Kinetic Ballooning Modes on the electron distribution function in the core of high-performance tokamak plasmas

Mazzi S. ; Giruzzi G. ; Camenen Y. ; Dumont R. ; Fontana M. ; de la Luna E. ; Orsitto F. P. ; Senni L. ; Aleynikova K. ; Brunner S. ; Frei B. J. ; Garcia J. ; Zocco A. ; Frigione D. ; Garzotti L. ; Rimini F. ; van Eester D.

This article is dedicated to study the physical causes of a long-standing issue experienced in different tokamak devices throughout the last decades: the observed discrepancies between electron cyclotron emission (ECE) and Thomson Scattering (TS) diagnostic measurements at high temperature in the core tokamak plasmas. A recently developed heuristic model (Fontana et al 2023 Phys. Plasmas 30 122503), tested on an extensive data set from multiple pulses in the frame of recent JET campaigns, showed that such ECE-TS discrepancy could be reconciled by introducing a bipolar perturbation in the electron distribution function. Such a perturbation indeed modifies the EC emission and absorption spectra. Nonetheless, the heuristic model does not provide the physical mechanisms causing such a bipolar perturbation. In this work, detailed gyrokinetic analyses unveil the unexplored wave-particle interaction between electrons and the Kinetic Ballooning Modes (KBMs) in tokamak plasmas. The numerical studies of the core of a selected high-temperature pulse of the JET device revealed that the electron-β was large enough to destabilize KBMs. Such KBMs affect the electron distribution function in momentum space with a characteristic bipolar structure. The position of the bipolar structure in the velocity space is intimately linked to the electron diamagnetic frequency. The amplitude of the perturbation, assessed through nonlinear computations, is shown to be dependent on the amplitude of the KBM-induced turbulent fluxes. Thus, this study demonstrates that KBMs, destabilized by the high-β plasma conditions achieved in the core of high-temperature scenarios, perturb the electron distribution function forming bipolar structures in momentum space and, thereby, modifying the EC spectrum. Therefore, the reported mechanism may represent an intriguing explanation of the ECE-TS measurement discrepancy in the deep core of high-temperature plasmas.

discrepancy ECE-Thomson electron distribution function high-performance fusion plasmas Kinetic Ballooning modes
CNR IRIS
2025 Articolo in rivista restricted access

Initial design of a real-time and an intershot bolometric data exploitation strategy for DTT

Peluso E. ; Apruzzese G. M. ; Belpane A. ; Palomba S. ; Senni L. ; Giovannozzi E. ; D'Agostino V. ; Craciunescu T. ; Gelfusa M. ; Gaudio P. ; Boncagni L.

One of the milestones to be achieved in the design of the bolometric diagnostics for the new Italian Divertor Tokamak Test (DTT) project is the estimation of the radiated power at the start of operation, i.e. the so-called first plasma, in order to perform various tasks ranging from scientific analysis and planning of the discharges to the feedback protection of the machine. In fact, real-time (RT) feedback control of the radiation pattern for prevention is both a delicate and important matter, for example in terms of mitigating and avoiding disruptions. It would therefore be desirable to monitor not only the total power emitted, but also the one emitted by the different regions of the plasma. This paper then focuses on showing the initial design of the main strategy for estimating the plasma radiation in two different situations: for RT control and for an inter-shot analysis. The first approach for RT then, is based on the estimation of the radiated power inside the first wall using specific lines of sight (LoS). Such estimates have been compared with those obtained from slower tomographic reconstructions of synthetic emissivity profiles (phantoms). Furthermore, a first design of the Region Of Interest (ROI) for a fast implementation of an already established macro-estimation of the radiated power in different locations of the main chamber is provided and the overall method is adapted for DTT. Regarding the design of the inter-shot data exploitation then, since tomographic reconstructions will most likely be available during an inter-shot basis, it is planned to provide a more accurate estimate of the radiated power from different locations of the device for a better design and tuning of the discharges. In order to achieve such a long-term goal, an initial strategy for adapting a maximum likelihood based algorithm for inter-shot analysis is described.

Data processing methods Nuclear instruments and methods for hot plasma diagnostics Plasma diagnostics - interferometry, spectroscopy and imaging
CNR IRIS
2025 Articolo in rivista restricted access

Maximum likelihood bolometric tomography for DTT diagnostic design

Peluso E. ; Craciunescu T. ; Apruzzese G. M. ; Belpane A. ; Palomba S. ; Senni L. ; D'Agostino V. ; Gelfusa M. ; Gaudio P. ; Boncagni L.

On both the Joint European Torus (JET) and the ASDEX-Upgrade (AUG) tokamaks, an Expectation Maximization algorithm has been adapted to implement a Maximum Likelihood (ML) approach to derive tomograms from bolometers data. The main feature of such an approach is the ability to estimate the variance associated with the reconstructed tomograms and hence the uncertainties in the derived quantities. It has therefore been selected to support the design of the bolometric diagnostics for the Divertor Tokamak Test Facility (DTT). A reliable reconstruction of the emissivity profile is indeed relevant for the scientific exploitation of the device. As any tomographic inversion method is an ill-conditioned problem, two milestones should be achieved: ensuring the reconstruction of specific features and minimizing the risk of producing artefacts. The design strategy for the bolometric diagnostic on DTT involves testing various possible layouts to ensure that they meet the above requirements and are compatible with the engineering and machine constraints. This contribution focuses on showing how the conceptual bolometric layout can handle different phantoms mimicking typical emissivities observed on JET and AUG. A methodology has been developed to further optimize the layout within the constraints of the machine design. For the initial phase of DTT, a reduced layout is proposed, utilizing half of the conceptual lines of sight. The ability to reconstruct specific emissivity features while minimizing the risk of producing artefacts has been tested. The current ML implementation uses an anisotropic diffusion technique and is already significantly faster than the JET implementation for each reconstruction.

Bolometry DTT Nuclear fusion Synthetic diagnostic Tokamak Tomography
CNR IRIS
2025 Articolo in rivista restricted access

Mechanical design of the bolometric and Soft-X ray diagnostics for DTT

Belpane A. ; Peluso E. ; Palomba S. ; D'agostino V. ; Regoli I. ; Spolaore B. ; Cesaroni S. ; Senni L. ; Bombarda F. ; Gelfusa M. ; Apruzzese G. M. ; Murari A. ; Gabellieri L.

In the European roadmap towards nuclear fusion, the new Italian project DTT (Divertor Tokamak Test), currently under construction at the ENEA Frascati Research Centre, aims at exploring alternative solutions for the divertor, in support to the optimization of the divertor configuration foreseen for DEMO. A dedicated set of diagnostics are planned to measure the total radiated power and to monitor plasma processes by means of Soft-X emission measurements. The total radiated power acquisition will rely on commercial metal resistor bolometers, while for the SXR range of energies a new technology based on custom Chemical Vapor Deposition diamonds (CVD) will be adopted. This work focuses on the mechanical layout design of these fundamental diagnostics, respecting geometrical and functional constrains of DTT and minimizing the diagnostics volume inside the access pipe. An integrated and compact solution, allowing flexible positioning and easy maintenance of the two systems has been identified, with a structural layout based on a modular approach. The detectors of the two diagnostics are installed on a common frame, with adjustable mounts for an independent fine-tuning of their alignment. The high heat load from the plasma is coped with by means of a custom active water-cooling system, to protect the sensors while ensuring stable and reliable operations. To allow a good physical exploitation of the collected data, i.e. with tomographic reconstructions, the lines of sight of both systems must be properly arranged on the poloidal section of the plasma. The proposed mechanical design foresees a customized chassis for each of the four poloidal ports of the DTT vacuum vessel, assuring a suitable coverage of the plasma's poloidal cross-section.

Nuclear instruments and methods for hot plasma diagnostics Plasma diagnostics - charged-particle spectroscopy Plasma diagnostics - interferometry, spectroscopy and imaging
CNR IRIS
2024 Articolo in rivista open access

THz Data Analysis and Self-Organizing Map (SOM) for the Quality Assessment of Hazelnuts

Greco M. ; Giarnetti S. ; Giovenale E. ; Taschin A. ; Leccese F. ; Doria A. ; Senni L.

In recent years, the use of techniques based on electromagnetic radiation as an investigative tool in the agri-food industry has grown considerably, and between them, the application of imaging and THz spectroscopy has gained significance in the field of food quality control. This study presents the development of an experimental setup operating in transmission mode within the frequency range of 18 to 40 GHz, which was specifically designed for assessing various quality parameters of hazelnuts. The THz measurements were conducted to distinguish between healthy and rotten hazelnut samples. Two different data analysis techniques were employed and compared: a traditional approach based on data matrix manipulation and curve fitting for parameter extrapolation, and the utilization of a Self-Organizing Map (SOM), for which we use a neural network commonly known as the Kohonen neural network, which is recognized for its efficacy in analyzing THz measurement data. The classification of hazelnuts based on their quality was performed using these techniques. The results obtained from the comparative analysis of coding efforts, analysis times, and outcomes shed light on the potential applications of each method. The findings demonstrate that THz spectroscopy is an effective technique for quality assessment in hazelnuts, and this research serves to clarify the suitability of each analysis technique.

agri-food industry hazelnut Kohonen’s algorithm millimeter waves quality assessment self-organizing map (SOM) terahertz
CNR IRIS
2024 Articolo in rivista restricted access

A thorough experimental assessment of THz-TDS plasma diagnostic techniques for nuclear fusion applications

Teka G. G. ; Peng K. ; Alonzo M. ; Bombarda F. ; Koch-Dandolo C. L. ; Senni L. ; Taschin A. ; Zerbini M.

In this paper, the study of a plasma diagnostic system based on the THz time domain spectroscopy technique is presented. Such a system could potentially probe a large part of the electromagnetic spectrum currently covered by several other diagnostics in a single measurement. This feature, keeping in mind the basic requirements for plasma diagnostics in nuclear fusion experiments, such as robustness and hard environment applicability, as well as durability and low maintenance, makes the diagnostic of great interest. A conceptual design of the THz-TDS diagnostic has been developed, starting from the well-established classical microwave and far infrared plasma diagnostics landscape. The physical constraints and required instrumental characteristics have been studied and are described in detail here, together with the solutions available for each type of plasma measurement. Specific experimental laboratory tests of the different experimental configurations have been carried out, evaluating the capacity and potential of the novel diagnostic, together with the instrumental constraint, within the diagnostic parameter space.

THz, TDS, Plasma, Diagnostic, Fusion
CNR IRIS
2024 Articolo in rivista metadata only access

Conceptual design of visible spectroscopy diagnostics for DTT

Belpane A. ; Carraro L. ; Fassina A. ; Cavedon M. ; Senni L.

The project of the Visible Spectroscopy diagnostics for the Zeff radial profile measurement and for the divertor visible imaging spectroscopy, designed for the new tokamak DTT (Divertor Tokamak Test), is presented. To deal with the geometrical constraints of DTT and to minimize the diagnostics volume inside the access port, an integrated and compact solution hosting the two systems has been proposed. The Zeff radial profile will be evaluated from the Bremsstrahlung radiation measurement in the visible spectral range, acquiring light along ten Lines of Sight (LoS) in the upper part of the poloidal plane. The plasma emission will be focused on optical fibers, which will carry it to the spectroscopy laboratory. A second equipment, with a single toroidal LoS crossing the plasma centre and laying on the equatorial plane, will measure the average Zeff on a longer path, minimizing the incidental continuum spectrum contaminations by lines/bands emitted from the plasma edge. The divertor imaging system is designed to measure impurity and main gas influxes, to monitor the plasma position and kinetics of impurities, and to follow the plasma detachment evolution. The project aims at obtaining the maximum coverage of the divertor region. The collected light can be shared among different spectrometers and interferential filter devices placed outside the torus hall to easily change their setup. The system is composed of two telescopes, an upper and a lower one, allowing both a perpendicular and a tangential view of the DTT divertor region. This diagnostic offers a unique and compact solution designed to cope the demanding constraints of this next-generation tokamak fusion devices, integrating essential tools for wide-ranging impurity characterization and versatile investigation of divertor physics.

diagnostics DTT effective charge visible spectroscopy
CNR IRIS
2024 Articolo in rivista open access

Gamma Irradiation Effect on Polymeric Chains of Epoxy Adhesive

Ferrante C. ; Lucchesi L. ; Cemmi A. ; Di Sarcina I. ; Scifo J. ; Verna A. ; Taschin A. ; Senni L. ; Beghini M. ; Monelli B. D. ; Raffaelli F.

The study of materials for space exploration is one of the most interesting targets of international space agencies. An essential tool for realizing light junctions is epoxy adhesive (EA), which provides an elastic and robust material with a complex mesh of polymeric chains and crosslinks. In this work, a study of the structural and chemical modification of a commercial two-part flexible EA (3MTM Scotch-WeldTM EC-2216 B/A Gray), induced by 60Co gamma radiation, is presented. Combining different spectroscopic techniques, such as the spectroscopic Fourier transform infrared spectroscopy (FTIR), the THz time-domain spectroscopy (TDS), and the electron paramagnetic resonance (EPR), a characterization of the EA response in different regions of the electromagnetic spectrum is performed, providing valuable information about the structural and chemical properties of the polymers before and after irradiation. A simultaneous dissociation of polymeric chain and crosslinking formation is observed.The polymer is not subject to structural modification at an absorbed dose of 10 kGy, in which only transient free radicals are observed. Differently, between 100 and 500 kGy, a gradual chemical degradation of the samples is observed together with a broad and long-living EPR signal appearance. This study also provides a microscopic characterization of the material useful for the mechanism evaluation of system degradation.

epoxy adhesive polymeric chains γray
CNR IRIS
2024 Articolo in rivista open access

Divertor Tokamak Test facility project: status of design and implementation

Romanelli F. ; Abate D. ; Acampora E. ; Agguiaro D. ; Agnello R. ; Agostinetti P. ; Agostini M. ; Aimetta A. ; Albanese R. ; Alberti G. ; Albino M. ; Alessi E. ; Almaviva S. ; Alonzo M. ; Ambrosino R. ; Andreoli P. ; Angelone M. ; Angelucci M. ; Angioni C. ; Angrisani Armenio A. ; Antonini P. ; Aprile D. ; Apruzzese G. ; Aquilini M. ; Aragone G. ; Arena P. ; Ariola M. ; Artaserse G. ; Aucone L. ; Augieri A. ; Auriemma F. ; Ayllon Guerola J. ; Badodi N. ; Baiocchi B. ; Balbinot L. ; Baldacchini C. ; Balestri A. ; Barberis T. ; Barone G. ; Barucca L. ; Baruzzo M. ; Begozzi S. ; Belardi V. ; Belli F. ; Belpane A. ; Beone F. ; Bertolami S. ; Bianucci S. ; Bifaretti S. ; Bigioni S. ; Bin W. ; Boccali P. ; Boeswirth B. ; Bogazzi E. ; Bojoi R. ; Bollanti S. ; Bolzonella T. ; Bombarda F. ; Bonan M. ; Bonanomi N. ; Bonaventura A. ; Boncagni L. ; Bonesso M. ; Bonfiglio D. ; Bonifetto R. ; Bonomi D. ; Borgogno D. ; Borzone T. ; Botti S. ; Boz E. ; Braghin F. ; Brena M. ; Brezinsek S. ; Brombin M. ; Bruschi A. ; Buonocore S. ; Buratti P. ; Buratti P. ; Busi D. ; Calabro G. ; Caldora M. ; Calvo G. ; Camera G. ; Campana G. ; Candela S. ; Candela V. ; Cani F. ; Cantone L. ; Capaldo F. ; Cappello S. ; Caponero M. ; Carchella S. ; Cardinali A. ; Carnevale D. ; Carraro L. ; Carrelli C. ; Casalegno V. ; Casiraghi I. ; Castaldo C. ; Castaldo A. ; Castro G. ; Carpignano A. ; Causa F. ; Cavazzana R. ; Cavedon M. ; Cavenago M. ; Cecchini M. ; Ceccuzzi S. ; Celentano G. ; Celona L. ; Centioli C. ; Centomani G. V. ; Cesaroni S. ; Chiariello A. G. ; Chomicz R. ; Cianfarani C. ; Cichocki F. ; Cinque M. ; Cioffi A. ; Ciotti M. ; Cipriani M. ; Ciufo S. ; Claps V. ; Claps G. ; Coccorese V. ; Coccorese D. ; Colangeli A. ; Coltella T. ; Consoli F. ; Cordella F. ; Corradini D. ; Costa O. ; Crea F. ; Cremona A. ; Crescenzi F. ; Crisanti F. ; Cristofari G. ; Croci G. ; Cucchiaro A. ; D'Ambrosio D. ; Dal Molin M. ; Dalla Palma M. ; Dane F. ; Day C. ; De Angeli M. ; De Leo V. ; De Luca R. ; De Marchi E. ; De Marzi G. ; De Masi G. ; De Nardi E. ; De Piccoli C. ; De Sano G. ; De Santis M. ; De Tommasi G. ; Del Nevo A. ; Delfino A. ; Della Corte A. ; Deodati P. ; Desiderati S. ; Di Ferdinando E. ; Di Florio M. G. ; Di Gironimo G. ; Di Grazia L. E. ; Di Marzo V. ; Di Paolo F. ; Di Pietro E. ; Di Pietrantonio M. ; Di Prinzio M. ; Di Silvestre A. ; Di Zenobio A. ; Dima R. ; Domenichelli A. ; Doria A. ; Dose G. ; Dubbioso S. ; Dulla S. ; Duran I. ; Eboli M. ; Elitropi M. ; Emanuelli E. ; Esposito B. ; Ettorre P. ; Fabbri C. ; Fabbri F. ; Fadone M. ; Faggiano M. M. ; Falcioni F. ; Falessi M. V. ; Fanale F. ; Fanelli P. ; Fassina A. ; Fassina A. ; Favaretto M. ; Favero G. ; Ferraris M. ; Ferrazza F. ; Ferretti C. ; Ferro A. ; Ferron N. ; Fiamozzi Zignani C. ; Figini L. ; Filippi F. ; Filippini M. ; Fimiani A. ; Fincato M. ; Fiorenza F. ; Fiorucci D. ; Flammini D. ; Flora F. ; Fonnesu N. ; Franz P. ; Frassinetti L. ; Frattolillo A. ; Freda R. ; Fresa R. ; Frescura A. ; Frosi P. ; Fulici M. ; Furno Palumbo M. ; Fusco V. ; Fusco P. ; Gabellier L. ; Gaetani P. ; Gaio E. ; Gajetti E. ; Gaetani P. ; Galata A. ; Galdon Quiroga J. ; Galindo Huertas D. L. ; Gammino S. ; Gandolfo G. ; Garavaglia S. ; Garcia Lopez J. ; Garcia Munoz M. ; Gaudio P. ; Gelfusa M. ; Gervasini G. ; Giannini L. ; Giarrusso M. ; Gil C. ; Giorgetti F. ; Giovannozzi E. ; Giruzzi G. ; Giudicotti L. ; Gobbin M. ; Gorini G. ; Granucci G. ; Grasso D. ; Grasso T. ; Grazioso S. ; Greuner H. ; Griva G. ; Grosso G. ; Guerini S. ; Gunn J. P. ; Hauer V. ; Hidalgo Salaverri J. ; Hoppe M. ; Houry M. ; Hoelzl M. ; Iaboni A. ; Iafrati M. ; Iaiunese A. ; Imbriani V. ; Indrigo D. ; Innocente P. ; Koechl F. ; Koncar B. ; Kryzhanovskyy A. ; Laguardia L. ; Lampasi D. A. ; Lanchi C. ; Lanzotti F. ; Lanzotti A. ; Laquaniti M. ; Leone F. ; Li J. ; Libe M. ; Lisanti F. ; Liuzza D. ; Locati F. ; Lombroni R. ; Lorenzini R. ; Lorusso P. ; Lotto L. ; Loureiro J. ; Lucca F. ; Luda Di Cortemiglia T. ; Maccari P. ; Maddaluno G. ; Magagnino S. ; Manca G. ; Mancini A. ; Mandala P. ; Mandolesi B. ; Mandrile F. ; Manduchi G. ; Manfrin S. ; Manganelli M. ; Mantica P. ; Marchiori G. ; Marconato N. ; Marelli G. ; Mariani A. ; Marin A. ; Marinari R. ; Marinelli M. ; Marino F. ; Marino P. ; Marocco D. ; Marsilio R. ; Martelli E. ; Martin P. ; Martinelli F. ; Martini G. ; Martone R. ; Marucci A. ; Marzullo D. ; Masala V. ; Mascali D. ; Mascari F. ; Masi A. ; Massanova N. ; Mastrostefano S. ; Mattei M. ; Mauro G. ; Mauro S. ; Meineri C. ; Melaragni L. ; Mele A. ; Meller P. ; Meloni S. ; Menicucci I. ; Messina G. ; Mezi L. ; Micciche G. ; Micheletti M. ; Migliori S. ; Milanesio D. ; Milazzo F. ; Milazzo R. ; Minelli P. ; Minucci S. ; Mirizzi F. ; Missirlian M. ; Monarca D. ; Monti C. ; Mori M. ; Moriani A. ; Morici L. ; Moro A. ; Moro A. ; Moro F. ; Mosetti P. ; Mozzillo R. ; Murari A. ; Muraro A. ; Murra D. ; Muscente P. ; Musumeci S. ; Muzzi L. ; Nallo G. F. ; Napoli F. ; Nardon E. ; Naselli E. ; Neu R. ; Nocente M. ; Notazio M. ; Nowak S. ; Ocello E. ; Oliva A. ; Orsetti V. ; Orsini A. ; Orsitto F. P. ; Ortino M. ; Ottavi M. ; Paccagnella G. ; Pacella D. ; Pagani I. ; Paganucci N. ; Pagliaro A. ; Palazzolo V. ; Palermo M. ; Palomba S. ; Panza F. ; Paoletti D. ; Parisi M. ; Pasqualotto R. ; Passarello S. ; Passoni M. ; Patton T. ; Pelliccia L. ; Peloso A. ; Pepato A. ; Perelli E. ; Perencin A. ; Peruzzo S. ; Pesenti A. ; Pedroni N. ; Petrolini P. ; Piergotti V. ; Pidatella A. ; Pigatto L. ; Pillon M. ; Pinna T. ; Pipolo S. ; Piras S. ; Piron C. ; Piron L. ; Pironti A. ; Pistilli M. ; Placido D. ; Pizzuto A. ; Platania P. ; Polimadei A. ; Pollastrone F. ; Polli G. M. ; Pomaro N. ; Pompili F. ; Ponti C. ; Porcelli F. ; Prandelli V. ; Previti A. ; Princiotta A. ; Pucino G. ; Quaglia F. ; Quercia A. ; Raffaelli F. ; Ramogida G. ; Ranieri G. ; Raspante B. ; Ravarotto D. ; Ravera G. L. ; Reale A. ; Rebesan P. ; Recchia M. ; Regine D. ; Renno F. ; Riccardi B. ; Ricci D. ; Rigamonti D. ; Ripani M. ; Rispoli N. ; Roccella S. ; Rocchi G. ; Roche H. ; Romanato M. ; Romanelli F. ; Romanelli F. ; Romanelli G. ; Romaniello R. ; Romano A. ; Romano M. ; Romano R. ; Rossi R. ; Rubinacci G. ; Rubino G. ; Rubino G. ; Rubino S. ; Rueda Rueda J. ; Rufoloni A. ; Salvia C. ; Salvini P. ; Scarpari M. ; Salvitti A. ; Salvo L. ; Sandri S. ; Santoro F. ; Satriano A. ; Savoldi L. ; Scardino C. ; Schettini G. ; Schmuck S. ; Scionti J. ; Sciscio M. ; Scungio M. ; Sedlak K. ; Senni L. ; Sias G. ; Sibio A. ; Simonetto A. ; Singh L. ; Sirignano A. ; Sozzi C. ; Spada I. ; Spagnolo S. ; Spinicci L. ; Spizzo G. ; Spolaore M. ; Stefanini C. ; Strobel H. ; Subba F. ; Taccogna F. ; Taheri B. ; Tantos C. ; Tarallo A. ; Tarantino M. ; Tardini G. ; Tardocchi M. ; Tarfila P. ; Tenaglia A. ; Terlizzi C. ; Terranova D. ; Testa D. ; Testa E. ; Testoni R. ; Toigo V. ; Torrisi G. ; Trotta A. ; Trovato G. ; Tsitrone E. ; Tuccillo A. ; Tudisco O. ; Turcato M. ; Turtu S. ; Uccello A. ; Ugoletti M. ; Uras O. ; Uras M. ; Utili M. ; Vaccaro V. ; Valentini F. ; Valletti L. ; Valisa M. ; Van Eester D. ; Vanzan D. ; Vassallo E. ; Vecchi G. ; Vellucci M. ; Venneri I. ; Ventura G. ; Veranda M. ; Verdini L. ; Verona C. ; Verona Rinati G. ; Veronese F. ; Vianello N. ; Vigano F. ; Villano O. ; Villari R. ; Villone F. ; Vincenzi P. ; Vitale V. ; Vivio F. ; Vlad G. ; Wischmeier M. ; Wu H. S. ; Wyss I. ; Zanino R. ; Zaniol B. ; Zanon F. ; Zappatore A. ; Zavarise G. ; Zito P. ; Zoppoli A. ; Zucchetti M. ; Zuin M. ; Zumbolo P.

An overview is presented of the progress since 2021 in the construction and scientific programme preparation of the Divertor Tokamak Test (DTT) facility. Licensing for building construction has been granted at the end of 2021. Licensing for Cat. A radiologic source has been also granted in 2022. The construction of the toroidal field magnet system is progressing. The prototype of the 170 GHz gyrotron has been produced and it is now under test on the FALCON facility. The design of the vacuum vessel, the poloidal field coils and the civil infrastructures has been completed. The shape of the first DTT divertor has been agreed with EUROfusion to test different plasma and exhaust scenarios: single null, double null, X-divertor and negative triangularity plasmas. A detailed research plan is being elaborated with the involvement of the EUROfusion laboratories.

divertor, exhaust, plasma scenarios
CNR IRIS
2024 Articolo in rivista open access

Experimental research on the TCV tokamak

Duval B. P. ; Abdolmaleki A. ; Agostini M. ; Ajay C. J. ; Alberti S. ; Alessi E. ; Anastasiou G. ; Andrebe Y. ; Apruzzese G. M. ; Auriemma F. ; Ayllon-Guerola J. ; Bagnato F. ; Baillod A. ; Bairaktaris F. ; Balbinot L. ; Balestri A. ; Baquero-Ruiz M. ; Barcellona C. ; Bernert M. ; Bin W. ; Blanchard P. ; Boedo J. ; Bolzonella T. ; Bombarda F. ; Boncagni L. ; Bonotto M. ; Bosman T. O. S. J. ; Brida D. ; Brunetti D. ; Buchli J. ; Buerman J. ; Buratti P. ; Burckhart A. ; Busil D. ; Caloud J. ; Camenen Y. ; Cardinali A. ; Carli S. ; Carnevale D. ; Carpanese F. ; Carpita M. ; Castaldo C. ; Causa F. ; Cavalier J. ; Cavedon M. ; Cazabonne J. A. ; Cerovsky J. ; Chapman B. ; Chernyshova M. ; Chmielewski P. ; Chomiczewska A. ; Ciraolo G. ; Coda S. ; Colandrea C. ; Contre C. ; Coosemans R. ; Cordaro L. ; Costea S. ; Craciunescu T. ; Crombe K. ; Dal Molin A. ; D'Arcangelo O. ; de Las Casas D. ; Decker J. ; Degrave J. ; de Oliveira H. ; Derks G. L. ; di Grazia L. E. ; Donner C. ; Dreval M. ; Dunne M. G. ; Durr-Legoupil-Nicoud G. ; Esposito B. ; Ewalds T. ; Faitsch M. ; Farnik M. ; Fasoli A. ; Felici F. ; Ferreira J. ; Fevrier O. ; Ficker O. ; Frank A. ; Fransson E. ; Frassinetti L. ; Fritz L. ; Furno I. ; Galassi D. ; Galazka K. ; Galdon-Quiroga J. ; Galeani S. ; Galperti C. ; Garavaglia S. ; Garcia-Munoz M. ; Gaudio P. ; Gelfusa M. ; Genoud J. ; Gerru Miguelanez R. ; Ghillardi G. ; Giacomin M. ; Gil L. ; Gillgren A. ; Giroud C. ; Golfinopoulos T. ; Goodman T. ; Gorini G. ; Gorno S. ; Grenfell G. ; Griener M. ; Gruca M. ; Gyergyek T. ; Hafner R. ; Hamed M. ; Hamm D. ; Han W. ; Harrer G. ; Harrison J. R. ; Hassabis D. ; Henderson S. ; Hennequin P. ; Hidalgo-Salaverri J. ; Hogge J. -P. ; Hoppe M. ; Horacek J. ; Huber A. ; Huett E. ; Iantchenko A. ; Innocente P. ; Ionita-Schrittwieser C. ; Ivanova Stanik I. ; Jablczynska M. ; van Vuuren A. J. ; Jardin A. ; Jarleblad H. ; Jarvinen A. E. ; Kalis J. ; Karimov R. ; Karpushov A. N. ; Kavukcuoglu K. ; Kay J. ; Kazakov Y. ; Keeling J. ; Kirjasuo A. ; Koenders J. T. W. ; Kohli P. ; Komm M. ; Kong M. ; Kovacic J. ; Kowalska-Strzeciwilk E. ; Krutkin O. ; Kudlacek O. ; Kumar U. ; Kwiatkowski R. ; Labit B. ; Laguardia L. ; Laszynska E. ; Lazaros A. ; Lee K. ; Lerche E. ; Linehan B. ; Liuzza D. ; Lunt T. ; Macusova E. ; Mancini D. ; Mantica P. ; Maraschek M. ; Marceca G. ; Marchioni S. ; Mariani A. ; Marin M. ; Marinoni A. ; Martellucci L. ; Martin Y. ; Martin P. ; Martinelli L. ; Martinelli F. ; Martin-Solis J. R. ; Masillo S. ; Masocco R. ; Masson V. ; Mathews A. ; Mattei M. ; Mazon D. ; Mazzi S. ; Mazzi S. ; Medvedev S. Y. ; Meineri C. ; Mele A. ; Menkovski V. ; Merle A. ; Meyer H. ; Mikszuta-Michalik K. ; Miron I. G. ; Molina Cabrera P. A. ; Moro A. ; Murari A. ; Muscente P. ; Mykytchuk D. ; Nabais F. ; Napoli F. ; Nem R. D. ; Neunert M. ; Nielsen S. K. ; Nielsen A. ; Nocente M. ; Noury S. ; Nowak S. ; Nystrom H. ; Offeddu N. ; Olasz S. ; Oliva F. ; Oliveira D. S. ; Orsitto F. P. ; Osborne N. ; Dominguez P. O. ; Pan O. ; Panontin E. ; Papadopoulos A. D. ; Papagiannis P. ; Papp G. ; Passoni M. ; Pastore F. ; Pau A. ; Pavlichenko R. O. ; Pedersen A. C. ; Pedrini M. ; Pelka G. ; Peluso E. ; Perek A. ; Von Thun C. P. ; Pesamosca F. ; Pfau D. ; Piergotti V. ; Pigatto L. ; Piron C. ; Piron L. ; Pironti A. ; Plank U. ; Plyusnin V. ; Poels Y. R. J. ; Pokol G. I. ; Poley-Sanjuan J. ; Poradzinski M. ; Porte L. ; Possieri C. ; Poulsen A. ; Pueschel M. J. ; Putterich T. ; Quadri V. ; Rabinski M. ; Ragona R. ; Raj H. ; Redl A. ; Reimerdes H. ; Reux C. ; Riedmiller M. ; Rienacker S. ; Rigamonti D. ; Rispoli N. ; Rivero-Rodriguez J. F. ; Madrid C. F. R. ; Rueda J. R. ; Ryan P. J. ; Salewski M. ; Salmi A. ; Sassano M. ; Sauter O. ; Schoonheere N. ; Schrittwieser R. W. ; Sciortino F. ; Selce A. ; Senni L. ; Sharapov S. ; Sheikh U. A. ; Sieglin B. ; Silva M. ; Silvagni D. ; Schmidt B. S. ; Simons L. ; Solano E. R. ; Sozzi C. ; Spolaore M. ; Spolladore L. ; Stagni A. ; Strand P. ; Sun G. ; Suttrop W. ; Svoboda J. ; Tal B. ; Tala T. ; Tamain P. ; Tardocchi M. ; Biwole A. T. ; Tenaglia A. ; Terranova D. ; Testa D. ; Theiler C. ; Thornton A. ; Thrysoe A. S. ; Tomes M. ; Tonello E. ; Torreblanca H. ; Tracey B. ; Tsimpoukelli M. ; Tsironis C. ; Tsui C. K. ; Ugoletti M. ; Vallar M. ; van Berkel M. ; van Mulders S. ; van Rossem M. ; Venturini C. ; Veranda M. ; Verdier T. ; Verhaegh K. ; Vermare L. ; Vianello N. ; Viezzer E. ; Villone F. ; Vincent B. ; Vincenzi P. ; Voitsekhovitch I. ; Votta L. ; Vu N. M. T. ; Wang Y. ; Wang E. ; Wauters T. ; Weiland M. ; Weisen H. ; Wendler N. ; Wiesen S. ; Wiesenberger M. ; Wijkamp T. ; Wuthrich C. ; Yadykin D. ; Yang H. ; Yanovskiy V. ; Zebrowski J. ; Zestanakis P. ; Zuin M. ; Zurita M. ; Ricci D.

Tokamak à configuration variable (TCV), recently celebrating 30 years of near-continual operation, continues in its missions to advance outstanding key physics and operational scenario issues for ITER and the design of future power plants such as DEMO. The main machine heating systems and operational changes are first described. Then follow five sections: plasma scenarios. ITER Base-Line (IBL) discharges, triangularity studies together with X3 heating and N2 seeding. Edge localised mode suppression, with a high radiation region near the X-point is reported with N2 injection with and without divertor baffles in a snowflake configuration. Negative triangularity (NT) discharges attained record, albeit transient, βN ∼ 3 with lower turbulence, higher low-Z impurity transport, vertical stability and density limits and core transport better than the IBL. Positive triangularity L-Mode linear and saturated ohmic confinement confinement saturation, often-correlated with intrinsic toroidal rotation reversals, was probed for D, H and He working gases. H-mode confinement and pedestal studies were extended to low collisionality with electron cyclotron heating obtaining steady state electron iternal transport barrier with neutral beam heating (NBH), and NBH driven H-mode configurations with off-axis co-electron cyclotron current drive. Fast particle physics. The physics of disruptions, runaway electrons and fast ions (FIs) was developed using near-full current conversion at disruption with recombination thresholds characterised for impurity species (Ne, Ar, Kr). Different flushing gases (D2, H2) and pathways to trigger a benign disruption were explored. The 55 kV NBH II generated a rich Alfvénic spectrum modulating the FI fas ion loss detector signal. NT configurations showed less toroidal Alfvén excitation activity preferentially affecting higher FI pitch angles. Scrape-off layer and edge physics. gas puff imaging systems characterised turbulent plasma ejection for several advanced divertor configurations, including NT. Combined diagnostic array divertor state analysis in detachment conditions was compared to modelling revealing an importance for molecular processes. Divertor physics. Internal gas baffles diversified to include shorter/longer structures on the high and/or low field side to probe compressive efficiency. Divertor studies concentrated upon mitigating target power, facilitating detachment and increasing the radiated power fraction employing alternative divertor geometries, optimised X-point radiator regimes and long-legged configurations. Smaller-than-expected improvements with total flux expansion were better modelled when including parallel flows. Peak outer target heat flux reduction was achieved (>50%) for high flux-expansion geometries, maintaining core performance (H98 > 1). A reduction in target heat loads and facilitated detachment access at lower core densities is reported. Real-time control. TCV’s real-time control upgrades employed MIMO gas injector control of stable, robust, partial detachment and plasma β feedback control avoiding neoclassical tearing modes with plasma confinement changes. Machine-learning enhancements include trajectory tracking disruption proximity and avoidance as well as a first-of-its-kind reinforcement learning-based controller for the plasma equilibrium trained entirely on a free-boundary simulator. Finally, a short description of TCV’s immediate future plans will be given.

EPFL plasma review SPC TCV
CNR IRIS
2024 Articolo in rivista restricted access

Conceptual design of visible spectroscopy diagnostics for DTT

Belpane, A. ; Carraro, L. ; Fassina, A. ; Cavedon, M. ; Senni, L.

The project of the Visible Spectroscopy diagnostics for the Zeff radial profile measurement and for the divertor visible imaging spectroscopy, designed for the new tokamak DTT (Divertor Tokamak Test), is presented. To deal with the geometrical constraints of DTT and to minimize the diagnostics volume inside the access port, an integrated and compact solution hosting the two systems has been proposed. The Zeff radial profile will be evaluated from the Bremsstrahlung radiation measurement in the visible spectral range, acquiring light along ten Lines of Sight (LoS) in the upper part of the poloidal plane. The plasma emission will be focused on optical fibers, which will carry it to the spectroscopy laboratory. A second equipment, with a single toroidal LoS crossing the plasma centre and laying on the equatorial plane, will measure the average Zeff on a longer path, minimizing the incidental continuum spectrum contaminations by lines/bands emitted from the plasma edge. The divertor imaging system is designed to measure impurity and main gas influxes, to monitor the plasma position and kinetics of impurities, and to follow the plasma detachment evolution. The project aims at obtaining the maximum coverage of the divertor region. The collected light can be shared among different spectrometers and interferential filter devices placed outside the torus hall to easily change their setup. The system is composed of two telescopes, an upper and a lower one, allowing both a perpendicular and a tangential view of the DTT divertor region. This diagnostic offers a unique and compact solution designed to cope the demanding constraints of this next-generation tokamak fusion devices, integrating essential tools for wide-ranging impurity characterization and versatile investigation of divertor physics.

diagnostics DTT effective charge visible spectroscopy
CNR IRIS
2024 Contributo in Atti di convegno restricted access

High beta experiments on JET in preparation of JT60SA

Orsitto F. P. ; Garzotti L. ; Pucella G. ; Gabriellini S. ; Auriemma F. ; Baruzzo M. ; Burckhart A. ; Bernardo J. ; Challis C. ; Dumont R. ; Hawkes N. ; Keeling D. ; King D. ; Mailloux J. ; Patel A. ; Piron C. ; Sozzi C. ; Zotta V. K. ; Senni L.

High beta discharges with dimensionless parameters collisionality (ν*), normalized toroidal Larmor radius (ρ*), and normalized beta (βN) relatively close to the JT-60SA scenarios hybrid and advanced were realized on JET: the JET ρ*=0.04 and bootstrap fraction fBS=0.4 were close to JT60SA values. So the discharges realized on JET are expected having comparable confinement properties as in JT60SA[1]. Since the maximum normalized beta βN_MAX≈ A-1/2 , is slowly dependent on the aspect ratio A, the equilibrium properties at high beta on JET (A=3.1) would not differ in JT60SA(A=2.5). Using the similarity scaling laws [1], JET pulses at BT/Ip (magnetic field/current)=2.4T/1.4MA are ‘similar’, i.e. share confinement and beta behaviour with the JT60SA scenario 5-1 with parameters BT=1.62T, Ip=1.4MA, and auxiliary heating power PAUX_JT60SA >10MW. The JET60SA high beta program can take profit of the high beta JET experiments in particular: i) in the phase of program development at BT=1.6-1.7T at low power to optimize the JT60SA current drive capabilities to get the full current drive , and ii) as a database for the validation of transport models. Strategy of JET experiments was to explore high normalized beta (βN) values, MHD effects at different Ip/BT and find parameters for discharges with mild MHD. Deuterium plasmas were realized in a variant of the hybrid-advanced scenario at toroidal magnetic field BT = 1.7, 2, 2.4 T, plasma current Ip = 1.4 MA, elongation k = 1.6, and high triangularity δ ≈ 0.4, q95=3.5-4.5, and central safety factor q0>1.2 at NBI start, with NBI power PNBI = 16-25 MW, no ICRH. Shots at BT=2.4T were realized in third Deuterium-Tritium (DTE3) campaign. The deuterium dataset is new. Pulses at BT=1.7/Ip=1.4MA are similar to 2014 Hybrid power scan at high δ[2], but there is an extension in the range of NBI power to PNBI=25MW. While pulses at BT=2.4T[3]. are executed at higher q95 with respect to the yr 2014 advanced pulses. Two scans were executed : i) a NBI power scan, affecting βN and ii) a NBI start time scan, affecting the central safety factor q0, which is a key ingredient for MHD stability of the high beta phase. Results of the experiments were: i) Good confinement properties and relatively high βN values; the betaN achievable increases with input power, βN>3.5 for BT/Ip=1.7T/ 1.4MA ; ii) Good control of q0 at start of main heating phase with NBI starting time t0_NBI depending on the toroidal magnetic field value, as investigated in JET hybrid and advanced scenarios; iii) Maximum βN≈ 2.5-2.7 with mild MHD at BT = 2.4 T and q0 > 1 (pulse#103116). Preliminary transport analysis has been done using Bohm-gyroBohm , QuaLiKiz , CDBM codes . The measured ion and electron temperature profiles and neutron fluxes are reproduced by CDBM code at all the magnetic fields. 1.Michele Romanelli and Francesco Paolo Orsitto PPCF 63(2021)125004 2.C Challis et al., Nucl. Fusion 55(2015) 053031 3.J Mailloux et al , 41st EPS Conf. Plasma Physics Berlin 2014 , O4.127. (*) see the author list of ‘Overview of T and D-T results JET with ITER-like wall’ by C Maggi et al. to be published in Nuclear Fusion Special Issue for IAEA FEC23 London 19-21 oct.2023.

Fusion, High Beta, JET, JT60SA
CNR IRIS
2023 Articolo in rivista open access

High Te discrepancies between ECE and Thomson diagnostics in high-performance JET discharges

Fontana M ; Giruzzi G ; Orsitto F ; de la Luna E ; Dumont R ; Figini L ; Kos D ; Maslov M ; Schmuck S ; Senni L ; Sozzi C ; Frigione D ; Garcia J ; Garzotti L ; Hobirk J ; Kappatou A ; Keeling D ; Lerche E ; Rimini F ; Van Eester D ; Maggi C ; Mailloux J

The present paper is dedicated to the study of the discrepancies encountered in electron temperature (Te) measurements carried out with electron cyclotron emission (ECE) and Thomson scattering (TS) diagnostics in the core of the JET tokamak. A large database of discharges has been collected, including high-performance scenarios performed with deuterium only and deuterium-tritium mixtures. Discrepancies have been found between core Te measurements taken with an X-mode ECE interferometer (TECE) and a LIDAR TS system (TLID) for Te > 5 keV. Depending on the plasma scenario, TECE has been found to be systematically higher or lower than TLID. Discrepancies have also been observed between the peaks of the ECE spectrum in the second (X2) and third (X3) harmonic domains, even in high optical thickness conditions. These discrepancies can be interpreted as evidence of the presence of non-Maxwellian features in the electron energy distribution function (EEDF). In order to investigate the relation between the shape of the EEDF and the measured discrepancies, a model for bipolar perturbations of Maxwellian EEDF has been developed. The model allows analytical calculations of ECE absorption and emission coefficients; hence, the comparison of modeled ECE spectra with experimental data. The different experimental results observed for the various JET scenarios have been found to be qualitatively reproducible by adapting the model parameters, suggesting that bipolar distortions of the bulk EEDF could play a role in giving rise to the reported discrepancies between ECE and TS measurements.

Deuterium Cyclotrons Distribution functions Electron cyclotron resonance Electron energy levels Magnetoplasma Optical radar
CNR IRIS
2023 Contributo in Atti di convegno restricted access

Selecting hazelnuts by coupling a self-organizing map (SOM) and an experimental system operating in transmission configuration

Greco M. ; Giarnetti S. ; Giovenale E. ; Senni L. ; Leccese F. ; Doria A. ; Taschin A.

An experimental setup operating in transmission mode in the frequency range between 18 and 40 GHz is described. This study shows how the system is able to distinguish healthy and rotten hazelnuts. In addition, a Self-Organizing Map (SOM) trained with the Kohonen algorithm was used to classify the hazelnuts according to their quality.

THz Food Sorting Self-Organizing Map
CNR IRIS
2023 Contributo in Atti di convegno restricted access

Electro-Optical determination of the Spectral Characteristics of components for THz-based Plasma Diagnostic

Taschin A. ; Senni L. ; Galatola-Teka G. ; Alonzo M. ; Doria A. ; Giovenale E. ; Zerbini M.

Since long time THz-TDS techniques have been seen as a good option for the measurements of plasma parameters [1]. This becomes a particularly interesting option for nuclear fusion experiments where Far Infrared and microwave diagnostics, in the frequency range 0.1-4000 THz, are one of the most important measurement tool [2] [3]. The application of THz-TDS techniques can potentially provide important plasma parameters, such as density, temperature and fluctuations, by using a multi-functional device with relatively small access requirements [4].

THz Time domain spectroscopy Plasma Diagnostics
CNR IRIS
2023 Contributo in Atti di convegno restricted access

A THz Scanner to Detect Moisture on Wood Samples

Greco M. ; Giovenale E. ; Leccese F. ; Doria A. ; Taschin A. ; Senni L.

Wood is a hygroscopic material that is subject to phenomena of water exchange with the external environment. These exchanges can cause dimensional variations and cracks to appear on a macroscopic level. In recent years, the use of terahertz technologies in the field of diagnostics applied to cultural heritage has increased considerably. One of the most important characteristics of terahertz radiation is its sensitivity to water content; this polar liquid strongly absorbs and reflects this radiation. The subject of this study will be the detection of moisture in pine wood samples using a 97 GHz terahertz imaging system.

THz Cultural Heritage Wood Moisture
CNR IRIS
2023 Contributo in Atti di convegno restricted access

Study on Differences of ECE and High-Resolution Thomson Scattering temperature measurements in DT (Deuterium-Tritium) plasmas on JET

Orsitto F. P. ; Fontana M. ; Giruzzi G. ; Senni L. ; Dumont R. ; Figini L. ; Kos D. ; Maslov M. ; Mazzi S. ; Schmuck S. ; Sozzi C. ; Challis C. ; Frigione D. ; Garcia J. ; Garzotti L. ; Hobirk J. ; Kappatou A. ; Keeling D. ; Lerche E. ; Maggi C. ; Mailloux J. ; Rimini F. ; van Eester D.

In Deuterium Plasmas differences were detected in JET between electron temperature measurements (Te) made by Electron Cyclotron Emission - Te_ECE - and Thomson Scattering diagnostics systems (Te_TS) [1]. Similar behaviour was found in TFTR [2]. Plasmas heated by ECRH (Electron Cyclotron Heating) in Deuterium on FTU showed T_ECE < T_TS for 8 KeV ≤ Te ≤ 14 keV [3]. These differences can be due to the non-Maxwellian nature of the Electron velocity Distribution Function (EDF) [5,6]. The radiation temperature (Trad) measured by ECE is equal to the Te only for a Maxwellian plasma: being Trad dependent on the derivative of the EDF with respect to perpendicular velocity [5]. This paper describes differences of Te measured by ECE (ECE_MP, Martin-Puplett interferometer) and High-Resolution Thomson Scattering (HRTS) diagnostic. HRTS gives independent information on these differences, having shorter space resolution (2 cm), and faster repetition rate (20 Hz) on a different line of sight (16 cm from the magnetic centre): HRTS measurements confirm the trends observed using LIDAR TS [4,5]. Comparison between HRTS and ECE radiometer measurements is also reported (see sec.3).

CNR IRIS