A5069728475- Magnetic confinement fusion research
- Fusion materials and technologies
- Dust and Plasma Wave Phenomena
- Ionosphere and magnetosphere dynamics
- Nuclear Materials and Properties
- Electrostatic Discharge in Electronics
- Plasma Diagnostics and Applications
- Diamond and Carbon-based Materials Research
- Particle accelerators and beam dynamics
- Electromagnetic Compatibility and Noise Suppression
- High-pressure geophysics and materials
- Lightning and Electromagnetic Phenomena
- Metal and Thin Film Mechanics
- Superconducting Materials and Applications
- Electromagnetic Launch and Propulsion Technology
- Earthquake Detection and Analysis
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- earthquake and tectonic studies
- Electromagnetic Simulation and Numerical Methods
- Thermal Analysis in Power Transmission
- Adhesion, Friction, and Surface Interactions
- Electric Motor Design and Analysis
- High voltage insulation and dielectric phenomena
- Combustion and Detonation Processes
University of Rome Tor Vergata
2024
Institute for the Science and Technology of Plasmas
2019-2023
National Research Council
2014-2021
Institute of Plasma Physics
2005-2019
National Agency for New Technologies, Energy and Sustainable Economic Development
2011-2016
Institute of Applied Physics
2016
Istituto di Matematica Applicata e Tecnologie Informatiche
2010
University of Perugia
1995-2003
The provision of a particle and power exhaust solution which is compatible with first-wall components edge-plasma conditions key area present-day fusion research mandatory for successful operation ITER DEMO. work package plasma-facing (WP PFC) within the European programme complements laboratory experiments, i.e. in linear plasma devices, electron ion beam loading facilities, studies performed toroidally confined magnetic such as JET, ASDEX Upgrade, WEST etc. connection both groups done via...
The first combined experimental and theoretical studies of dust remobilization by plasma forces are reported. main aspects in fusion devices under steady state conditions analyzed. In particular, the dominant role adhesive is highlighted generic conditions—direct lift-up, sliding, rolling—are formulated. A novel technique proposed, based on controlled adhesion grains tungsten samples with detailed mapping deposition profile prior post exposure. Proof-of-principle experiments TEXTOR tokamak...
Since the 2012 IAEA-FEC Conference, FTU operations have been largely devoted to runaway electrons generation and control, exploitation of 140 GHz electron cyclotron (EC) system liquid metal limiter elements. Experiments on shown that measured threshold electric field for their is larger than predicted by collisional theory can be justified considering synchrotron radiation losses. A new control algorithm was developed tested in presence a current plateau, allowing minimize interactions with...
Abstract The first study of the interaction metallic dust (tungsten, aluminum) adhered on tungsten substrates with transient plasma heat loads is presented. Experiments were carried out in Pilot-PSI linear device fluxes up to 550 MW m −2 and DIII-D divertor tokamak. central role dust-substrate contact area conduction highlighted confirmed by transfer simulations. experiments provide evidence occurrence wetting-induced coagulation, a novel growth mechanism where cluster melting accompanied...
Dust trajectories have been recorded with an unprecedented, under fusion-relevant plasma conditions, spatial resolution of 9 μm/pixel in Pilot-PSI. The optical setup allowed the use fast cameras as a basic microscope. It is demonstrated that such essential for correct interpretation experiments on several aspects dust-surface interactions. Highly resolved tungsten dust dynamics measurements are presented from dedicated collisions facing components, motion vicinity castellated samples and...
The first experimental determination of the pull-off force for tungsten dust adhered to surfaces is reported. Dust deposition conducted with gas dynamics methods in a manner that mimics sticking as it occurs tokamak environment. Adhesion measurements are carried out electrostatic detachment method. adhesion strength systematically characterized spherical micron different sizes and planar varying roughness. nearly two orders magnitude smaller than predictions contact mechanics models, but...
Remobilization is one of the most prominent unresolved fusion dust-relevant issues, strongly related to lifetime dust in plasma-wetted regions, survivability on hot plasma-facing surfaces and formation accumulation sites. A systematic cross-machine study has been initiated investigate remobilization tungsten micron-size from implementing a newly developed technique based controlled pre-adhesion by gas dynamics methods. It utilized number devices provided new insights under steady-state...
Post-mortem and in-situ evidence is presented in favor of the generation high-velocity solid dust during explosion-like interaction runaway electrons with metallic plasma-facing components FTU. The freshly-produced source secondary de-localized wall damage through impacts that lead to formation craters, which have been reproduced dedicated light gas gun impact tests. This novel mechanism, potential importance for ITER DEMO, further supported by surface analysis, multiple theoretical...
GyM is a linear plasma device operating at Istituto per la Scienza e Tecnologia dei Plasmi, Consiglio Nazionale delle Ricerche, Milan, with the original aim of studying basic physics, such as turbulent processes. Since 2014, experimental program has been mainly focused on issue plasma-material interaction (PMI) for magnetic confinement nuclear fusion applications. consists stainless steel vacuum chamber (radius and length 0.125 m 2.11 m), pumping system, gas injection 10 field coils two...
Charged dust particles are theoretically expected to modify the amplitude and spectrum of plasma fluctuations, this can eventually provide novel diagnostic tools. Direct experimental evidence effects on fluctuations a low collisionality is reported, in agreement with expectations kinetic theory.
The new collective Thomson scattering diagnostic installed on the Frascati Tokamak Upgrade device started its first operations in 2014. ongoing experiments investigate presence of signals synchronous with rotating tearing mode islands, possibly due to parametric decay processes, and phenomena affecting electron cyclotron beam absorption or measurements. radiometric system, layout, data acquisition system were improved accordingly. present status near-term developments are presented.
Comprehensive measurements of the adhesive force for tungsten dust adhered to surfaces have been performed with electrostatic detachment method. Monodisperse spherical has deposited gas dynamics techniques or gravity mimicking adhesion as it naturally occurs in tokamaks. The is confirmed follow log-normal distribution and empirical correlations are proposed size-dependence its mean standard deviation. Systematic differences observed between two deposition methods attributed plastic...
Dust-wall high speed impacts, triggered by the termination of runaway electrons on plasma facing components, constitute a source erosion. Normal velocity mechanical impacts tungsten dust bulk plates are reproduced in controlled manner light gas gun shooting systems. Post-mortem surface analysis revealed that three erosion regimes realized; plastic deformation, bonding and partial disintegration. The large impact statistics allowed extraction reliable empirical damage laws latter regime,...
Castellated substrates with adhered micron dust have been exposed in the outer ASDEX-Upgrade divertor to ELMy H-mode discharges. Beryllium proxy (chromium, copper) and refractory metal (tungsten, molybdenum) has deposited on plasma-facing plasma-shadowed sides of monoblocks as well bottom gaps. Interaction time-averaged transient heat loads up 5 MW m−2 led remobilization, clustering, melting wetting-induced coagulation. The amount released vessel quantified remobilized trajectories inferred....
A comprehensive analysis of composition and morphology metallic micrometric particles collected in FTU during the 2013 shut-down is presented. The data-set analyzed result years experimental activity which a full metal machine since beginning operation with liquid lithium limiter (LLL) from 2005. It was found that population, consisting flakes, smashed spheroidally shaped plasma facing components (mainly SS Mo), exhibits an unexpectedly high, up to 70 wt%, fraction magnetic grains. change...
It is shown that the measurements of density fluctuation spectra in dusty plasmas can constitute a basis for situ diagnostic invisible submicron dust. The self-consistent kinetic theory includes charging processes and natural fluctuations dust particles predicts modifications due to presence A laboratory experiment was carried out where produced gas phase diagnosed by surface analysis samples its influence on plasma spectra. Quantitative comparison latter with yields information density,...
Mechanical dust-wall collisions are unavoidable in fusion devices and their accurate modeling is essential for the understanding of dust transport. The MIGRAINe dynamics code features analytical models addressing all facets dust-surface impacts, some aspects which have not been experimentally validated thus far. Dedicated injection experiments carried out Pilot-PSI resulting to visualization in-plasma tungsten impacts with an unprecedented resolution. They allowed a calibration key...
Experimental evidence of the pre-plasma remobilization ferromagnetic dust in FTU is presented. Thomson scattering data and IR camera observations document occurrence intrinsic prior to discharge start-up allow for a rough calculation average mobilized density. Exposures calibrated extrinsic non-magnetic sole magnetic field discharges reveal that moment force main mobilizing force, as confirmed by theoretical estimates. Pre-plasma probabilities are computed varying sizes. The impact...
Anomalous emissions were found over the last few years in spectra of Collective Thomson Scattering (CTS) diagnostics tokamak devices such as TEXTOR, ASDEX and FTU, addition to real CTS signals. The signal frequency, down-shifted with respect probing one, suggested a possible origin Parametric Decay Instability (PDI) processes correlated presence magnetic islands occurring for pumping wave power levels well below threshold predicted by conventional models. A or close Electron Cyclotron...
Abstract Since the 2016 IAEA Fusion Energy Conference, FTU operations have been mainly devoted to experiments on runaway electrons and investigations into a tin liquid limiter; other involved studies of elongated plasmas dust. The tearing mode onset in high density regime has studied by means linear resistive code MARS, highly collisional regimes investigated. New diagnostics, such as electron imaging spectroscopy system for in-flight triple Cherenkov probe measurement escaping electrons,...