Developing fusion energy entails the combination of many different disciplines including plasma physics, materials physics and engineering, computer science. In this talk, an overview will be given of the physics and technology in view of magnetic fusion reactors, including the recent achievements, the current challenges and the main developments. The contributions that the new Divertor...
The Divertor Tokamak Test facility (DTT) [1] is a research infrastructure proposed first in the EFDA Roadmap [2] to investigate innovative solutions for the heat exhaust in the DEMOnstration fusion power plant.
DTT is a compact experiment (major radius R=2.2m, minor radius 0.7m) that mimic the heat generated by fusion reactions using a large amount of external heating power (up to 45MW at...
In this joint talk, we will provide an overview of plasma physics research in the context of space and astrophysical environments, charting a journey from our local heliosphere to distant compact objects. We will begin by covering the fundamentals of heliospheric plasmas, including the physics of the solar corona, the properties of the solar wind, and the dynamics of near-Earth plasmas [1]. We...
Astrophysical jets are highly collimated outflows observed in a wide range of astronomical systems, from young stellar objects and X-ray binaries to active galactic nuclei (AGN). These jets are intimately linked to the accretion processes occurring around forming stars or supermassive black holes at the centers of galaxies. I will focus on the extragalactic case, where jets are accelerated to...
I will discuss the main plasma physics challenges to understand how particles scatter inside their acceleration region, around their sources and in the medium between the source and the observer. I will outline how non-linear process are expected to play a crucial role in all of these cases and their phenomenological implications.
X-ray synchrotron radiation is expected to be highly polarized. Thanks to the Imaging X-ray Polarimetry Explorer (IXPE), it is now possible to evaluate the degree of X-ray polarization in sources such as supernova remnants (SNRs). Jointly using IXPE data and high-resolution Chandra observations, we perform a spatially resolved spectropolarimetric analysis of SNR Cassiopeia A (Cas A). We focus...
A Low-Temperature Plasma (LTP) is a partially ionized gas in which electron energies are of the order of the ionisation potential of atoms and molecules, typically of a few eV, while the ions and the neutral are at low energy, close to room temperature. Essentially, this plasma represents a non-equilibrium system, with the electron temperature being higher than the ion temperature, even of...
A single-species (e.g., electron) plasma can have a theoretically indefinite lifetime in a magneto-electrostatic device such as a Penning-Malmberg trap, a linear, azimuthally-symmetric electrostatic confinement environment immersed in an intense axial magnetic field. Here the transverse dynamics of the sample is isomorphic to the one exhibited by a two-dimensional ideal fluid – with...
Physical vapor deposition (PVD) is a vacuum-growth method that allows the deposition of thin films and coatings on a substrate by physically vaporizing a source material and condensing it on the substrate [1]. PVD systems are of pivotal importance in many science and technology fields creating coatings that enhance a material's hardness, wear resistance, and appearance as well as constitute...
Italy has a long and prestigious history of research activity related to the field of laser/beam plasma interaction and inertial confinement fusion, dating back to the last century and spanning many decades. Pioneering experiments and theoretical research have been conducted in our country in this broad field, providing our research groups with the knowledge and expertise necessary to build...
Laser–plasma radiation sources based on solid targets [1] are promising for a wide range of applications, from nuclear medicine to materials characterization. They are attractive because they can generate various types of radiation (e.g., high-energy electrons, ions, neutrons, and γ-rays), allow for energy tuning, and can operate within compact setups. This versatility relies on the precise...
Il Centro Italiano Ricerche Aerospaziali (CIRA) dal 2015 è impegnato nella ricerca e sviluppo di tecnologie di propulsione elettrica spaziale, con focus su propulsori al plasma che possano abilitare le missioni spaziali di prossima generazione (es. richiedenti alta efficienza, utilizzo di risorse in sito e/o propellenti atmosferici, spinte molto basse e talvolta alte). Le attività di ricerca...
The Plasma Control System (PCS) is an essential component of any tokamak, responsible for the real-time management of the plasma to ensure stable operation and optimal performance during fusion experiments. It works in conjunction with other subsystems to monitor and control key parameters during a plasma discharge like the plasma shape, position, density, and temperature.
The DTT PCS...
The Divertor Tokamak Test (DTT) facility is a large experiment under design and construction at the ENEA Research Centre in Frascati, Italy. Its main goal is to assess alternative solutions for the heat and power exhaust problem in future fusion plants [1]. To this end, different configurations will be tested, and safe operation must be ensured in all of them.
One of the major challenges in...
In a tokamak plasma, impurities can diffuse depending on their atomic mass. One of the main (unwanted) source of impurities is erosion or sputtering of the first wall and of the divertor. The presence of different kind of impurities can modify the plasma dynamics, trigger instabilities, and dissipate energy through radiation.
In the past years, JET-ILW (ILW is for ITER-Like-Wall composed by a...
The intense-laser interaction with low-density nanostructured materials has received increased interest owing to the peculiar regime they enable [1]. This interaction regime, characterised by increased coupling between the laser radiation and the plasma, enables a more efficient heating of the plasma species without any change in the laser parameters, both at ultra-high intensities...
The research activity of the Intense Laser Irradiation Laboratory (ILIL) at Istituto
Nazionale di Ottica in Pisa is focused on fundamental studies of high-intensity laser
interaction with matter and their applications. The Laboratory participates to the
European Infrastructures EuPRAXIA, ELI and HiPER+ and is a member of the
Laserlab-Europe AISBL. Fundamental studies include plasma...
Particle-in-cell (PIC) simulations are a well-established tool to study and predict the outcomes of a Laser Plasma Accelerator experiment, but the results are often hindered by the initialization of highly idealized laser profiles. In this work, we present the development of a Laser Pulse reconstructor For Particle In Cell simulations (LP4PIC), a Python package to retrieve experimental laser...
The ITER experiment will employ two Neutral Beam Injection (NBI) systems to achieve the
temperatures required for the deuterium-tritium fusion reaction to occur. Each injector relies
on a negative ion source, in which a low-pressure deuterium plasma is sustained by radiofrequency (RF) power through inductive coupling. The performance of the sources, in terms
of power coupling efficiency...
Axisymmetric modes (toroidal mode n=0) are considered to play an influential role in the stability of future tokamak fusion plasmas where the large presence of fusion alpha particles can potentially drive these modes [1]. Among them, two possible ones are the well-known GAE (Global Alfven Eigenmode), and the newly emerged VDOM (Vertical Displacement Oscillatory Modes) [2]. Being global in...
Recent progress on the theory, numerical simulations, and experimental observations of Vertical Displacement Oscillatory Modes (VDOM) in tokamak experiments is reported. VDOM are axisymmetric modes (toroidal mode number n=0) driven unstable by energetic particles and can have an impact on plasma disruptions, plasma edge stability and confinement. They are a candidate to explain...
P. Buratti (1, 2), W. Bin (3), A. Cardinali (2), C. Castaldo (1), F. Napoli (1), M. Guerini Rocco (3, 4) and B. Moshref (5)
(1) ENEA, NUC Department, Via E. Fermi 45, 00044 Frascati, Italy
(2) INAF-IAPS, via Fosso del Cavaliere 100, I-00133 Rome, Italy
(3) ISTP-CNR, Via R. Cozzi 53, 20125 Milan, Italy
(4) Department of Physics, University of Milano-Bicocca, Milan, 20126, Italy
(5)...
As comprehensively reviewed in [1], enormous volume of work has been carried out in understanding and control of various MHD instabilities, in particular in the Tokamak configurations and significant progress has been achieved. Yet, unresolved issues remain, where the MHD description is expected to play important contributions. We here present a survey of our activity focussed to the...
Plasma–material interactions are a key challenge for magnetic confinement fusion and are widely investigated in linear plasma devices. The GyM [1] linear device currently operates at plasma densities of $10^{15}–10^{17}\text{m}^{-3}$, electron temperatures below 15 eV, and ion fluxes up to $10^{21} \text{m}^{-2} \text{s}^{-1}$, representative of tokamak main chamber conditions.
To reach...
The simulation of plasmas and their containing surfaces involves many aspects, so that a careful choice of the multiphysics relevant model is necessary. Note that ion sources (IS) for accelerators are necessarily bounded by metal or insulator walls, so that their physical characteristic should be accounted for. Moreover charge large sheaths develop near walls, and an ambipolar potential...
Il trasporto di particelle ed energia in un tokamak è prevalentemente di natura turbolenta e costituisce un aspetto cruciale per il confinamento del plasma. La sua comprensione risulta quindi necessaria per la pianificazione dei futuri reattori e per la massimizzazione della performance. Da un punto di vista empirico, la turbolenza si manifesta tramite coefficenti di trasporto cosiddetti...
Laser-Induced Breakdown Spectroscopy (LIBS) is a promising diagnostic technique for monitoring PFCs during and after plasma exposure, enabling the assessment of elemental and isotopic composition through optical emission spectroscopy. For quantitative depth profiling and fuel retention studies, accurate knowledge of the ablation rate and thermal effects induced by a single laser pulse is...
The research on Inertial Confinement Fusion (ICF) requires constant research for identifying new materials. Micro-structured low-density materials, or foams, with a randomly arranged internal structure, have been shown mitigate, to some extent, the detrimental effect due to hydrodynamic instabilities seeded by non-uniform irradiation, while also increasing the laser absorption efficiency and...
We propose and test a multi-step preliminary analytical procedure that tailors the initial
density fn0 of a cold diluted collisionless plasma to a very short and intense plane-wave
laser pulse travelling in the z direction, so as to maximize the early laser wakefield acceleration
(LWFA) of bunches of plasma electrons self-injected in the plasma wave (PW) by the
first wave-breaking (WB) at...
In tokamak fusion devices, Plasma-Wall Interaction (PWI) represents one of the main concerns for future reactors. Indeed, such phenomena lead to the erosion of Plasma Facing Components (PFCs), resulting in the transport of eroded particles into the plasma and their subsequent redeposition. These processes significantly affect plasma confinement performance, as well as the lifetime and...
Neutron measurements are of crucial importance for the forthcoming DT fusion reactors as they allow to measure the fusion power, which is a primary parameter to evaluate the fusion performance.
The standard method for fusion power measurement is based on counting neutrons with fission chambers cross-calibrated with activation foils. This method requires complex Monte Carlo simulations...
The Plasma Unit of the Institute of Complex Systems of the CNR at the Politecnico di Torino focuses on the theoretical and numerical analysis of magnetic reconnection processes in plasmas of interest for both space and fusion applications. In particular, we study the fundamental processes that govern the interaction between magnetic reconnection and fluid turbulence [1,2], the instability of...
When a high-intensity laser interacts with matter, it creates a plasma, thus emitting particles and generating strong electromagnetic (EM) radiation. We focus for this study on the emitted EM fields ranging from MHz to THz, known as electromagnetic pulses (EMPs). These EMPs, originating from various sources in laser-matter interactions [1], can reach peak intensities of the MV/m order, posing...
Laser-accelerated electron beams, in the so-called Very High-Energy Electron (VHEE) energy range, are of great interest for biomedical applications, particularly for developing compact accelerators for FLASH radiotherapy. Reliable real-time dose information is essential for radiobiology experiments using such laser-driven sources. We present an online dose-monitoring method based on an...
Electron accelerators based on the so-called Laser WakeField Acceleration process, whose experimental study has been mostly taken place over the past 20-30 years, have now reached a sufficient maturity to be considered for several applications. Among these, their use as compact devices for novel, and possibly more effective, radiotherapy modalities is deserving a great and growing...
The interaction of high-intensity laser pulses with matter generates a wide range of physical phenomena, including particle acceleration and emission of pulsed electromagnetic radiation ranging from ionizing (γ, X, UV) to non-ionizing frequencies. Among these emissions, Electromagnetic Pulses (EMPs) extend from the MHz to the THz range [1] and can reach field strengths of several MV/m at...
In the framework of magnetic reconnection studies, and in collaboration with EUROfusion partners, we study how the presence of a large magnetic island, like the ones due to a (neoclassical) tearing mode in a tokamak, changes the transport in radial direction (core to edge and vice versa) [1]. The general purpose is to study the interplay between such an island and the accumulation of tungsten...
In magnetic confinement fusion, tokamak plasmas with negative triangularity (NT) have emerged as a promising alternative to H-mode operation scenarios, achieving high confinement while remaining in L-mode, thus inherently free of edge-localized modes [1]. Recent experiments in Tokamak a Configuration Variable (TCV) have shown that NT plasmas feature more challenging access to divertor...
This work provides an overview of the progress achieved so far in the electromagnetic simulation of plasma instability phenomena in tokamaks, focusing on the Divertor Tokamak Test (DTT). The main aim is to provide a concise summary of the current strategies for disruption mitigation, focusing on Shattered Pellet Injection (SPI), seen as the primary disruption mitigation method during the...
In magnetized plasmas, there are many dynamical processes that affect the ion velocity distribution function, both in laboratory and astrophysical environments. Measurements of this quantity can give useful insights for the study of phenomena such as magnetic reconnection, ion heating and acceleration, and turbulence activity. For this purpose, we designed a new diagnostic system that...
The Tuscia Research University Small Tokamak (TRUST) is a compact university-scale device currently under design at Università degli Studi della Tuscia. Conceived as a flexible and cost-effective platform, TRUST supports education, technology development, and physics studies of relevance to next-generation fusion devices. The conceptual design foresees a baseline single-null configuration with...
The projects of neutron sources based on nuclear fusion is becoming an important argument for the strategic positioning of the road-map of fusion realization worldwide. In this context, the paper presents a NEW innovative conceptual study of a neutron source based on a spherical tokamak(ST). The plasma scenario chosen for the ST is non-thermal fusion ( hot ion mode) , extensively used on...
Abstract:
During the DTE2 and DTE3 JET campaigns, efforts were made to develop a high-current baseline scenario [1]. Baseline plasmas were affected by impurities (primarily beryllium Be and tungsten W), which were localised on the low-field side of the device. Tomograms derived from bolometric measurements highlighted regions of high radiated emissivity at the periphery of the plasma....
Plasma disruption events are responsible for the most important transient EM and thermal loads on the plasma chamber, the in-vessel components and other conducting structures neighboring the plasma. This work reviews the simulations of plasma disruption carried out, by different MHD codes, to support the design of vacuum vessel and other components in facility DTT Divertor Tokamak Test [1],...
The RFX-mod device is a toroidal device for the magnetic confinement of fusion relevant plasmas, which is presently being upgraded and is planned to restart operation as RFX-mod2 with a modified and improved magnetic boundary. Thanks to the flexibility of its power supply and advanced feedback control systems it can be operated in a variety of configurations, mainly the tokamak and the...
In the last decade, single crystal diamond detectors have been extensively used at JET for neutron spectroscopy measurements along collimated lines of sight. Although diamonds can measure 2.5 MeV neutrons, their use is optimized for 14 MeV neutrons. This is due to the exploitation of the 12C(n-)9Be nuclear reaction channel which results in a well-defined gaussian peak in the recorded energy...
In modern magnetic fusion devices plasma temperatures of several keV are obtained, so that relativistic effects may play an important role on the electron kinetics. We report here on the development of a new 2.5D fully relativistic, bounce-averaged Fokker-Planck code, suitable for the simulation of the radio frequency heating in both tokamaks and stellarators.
The present code represents a...
Forward and inverse problems play a fundamental role in many areas of plasma physics and nuclear fusion, including plasma performance prediction, instability evolution analysis, transport modelling, equilibrium reconstruction, and tomography. Typically, forward numerical models are developed under specific assumptions, and their parameters are iteratively adjusted to match experimental data....
Developing open, transparent, and transferable knowledge frameworks is essential for advancing plasma physics research and supporting both theoretical and experimental studies. In this context, we have developed TokaLab: an open-access virtual tokamak designed for education and research. This repository aims to foster learning, collaboration, and the adoption of the FAIR principles (Findable,...
Understanding the mechanisms that govern the turbulent dynamics in tokamak devices is of primary interest for achieving a net production of energy from nuclear fusion processes.
In this work, we investigate the turbulent transport of blob-like structures in the Scrape-Off Layer by means of numerical simulations based on the reduced Braginskii equations in a simplified geometry. We derive a...
One of the main challenges in magnetically confined fusion research is the development of plasma-facing materials able to withstand the harsh environment of long-term plasma exposure. Linear plasma devices are widely used to address this issue. GyM [1] is one such device, capable of generating steady-state plasmas with electron temperatures up to 15 eV, densities in the range of...
Plasma wakefield acceleration (PWFA) represents one of the most promising routes toward compact high-gradient accelerators. While its modeling has long relied on the cold-plasma approximation, several physical and technological developments now call for the inclusion of finite temperature effects. Thermal pressure becomes relevant near the wavebreaking threshold, where it regularizes singular...
Understanding plasma–wall interaction is a key step on the path towards the exploitation of nuclear fusion energy [1]. The erosion of plasma-facing components (PFCs) can shorten their lifetime, while the eroded material — typically tungsten (W), owing to its favourable plasma-interaction properties — may contaminate the confined plasma, degrading the performance through fuel dilution and...
Electron beams produced via Laser Wakefield Acceleration are notoriously known for their pointing instability, which makes the retrieval of the energy spectrum via magnetic spectrometers prone to energy miscalculations. Here, we demonstrate an improved scheme of a previously published spectrometer employing two scintillating screens and a magnetic dipole in between. The first screen provides...
Mitigating the heat load to the divertor is a key challenge for future fusion reactors. Current material limits constrain the allowable heat flux to below 10 MW/m², requiring a significant fraction of the power exhausted from the core plasma to be radiated to maintain acceptable conditions at the divertor. In next-step devices, such as ITER and DEMO, sustained operation without damage demands...
Over almost the past six decades, a fleet of space missions, strategically placed throughout the heliosphere at critical vantage points, have been devoted to the exploration of the interplanetary space, greatly advancing our knowledge of how the Sun influences the whole solar system, through the solar wind, a continuous flow of charged particles emitted by the outer layer of the solar...
Ionospheric equatorial plasma bubbles/depletions are plasma density irregularities, which tend to develop under specific conditions during post-sunset hours and continue to evolve non-linearly into the post-midnight period. The Rayleigh–Taylor (Kruskal-Shafranov) instability mechanism is believed to be responsible for the formation of these depletions. An intriguing feature of equatorial...
EuPRAXIA is the first European project devoted to create a particle accelerator research infrastructure based on plasma acceleration and laser and linac technology.
The project aims at developing plasma-based particle accelerator facilities, exploiting the intrinsic high gradient of up to 100 GV/m to improve the sustainability of particle accelerators. Furthermore, EuPRAXIA foresees to employ...
Neutral beam injectors are widely used to provide magnetically confined plasmas with additional heating, current drive and, in the case of medium size devices, torque. ITER will feature 2(3) heating neutral injectors (HNBs) delivering up to 16.7 MW of neutral H0/D0 with 870 keV/1 MeV energy. Neutralization of positive ion beams at 1 MeV is practically impossible so that the precursor of the...
High‑power laser driven inertial fusion energy (IFE) is entering a pivotal phase in Europe, building upon the HiPER+ flagship initiative. Coordinated experimental access to existing national and international facilities supports laser development and the study of laser–plasma interactions and high‑energy‑density (HED) physics for direct‑drive implosions, providing a platform for advancing...
La spettroscopia ottica rappresenta uno strumento fondamentale per lo studio dei plasmi da fusione, poiché consente di ottenere in modo non perturbativo informazioni cruciali sulle proprietà del plasma e sulla dinamica delle impurezze, determinanti per conoscere le perdite di energia
Il conseguimento simultaneo di un miglior confinamento energetico e di un basso confinamento delle impurità è...
Le dinamiche su scala cinetica nei plasmi spaziali debolmente collisionali mostrano una statistica autosimilare delle fluttuazioni del campo magnetico e l'esistenza di una funzione di densità di probabilità invariante (master curve). È possibile derivare analiticamente la master curve a partire da una dinamica à la Langevin, ottenendo una generalizzazione della distribuzione Kappa a due...
This study leverages a fully compressible 3D Hall-MHD numerical simulation of space plasma turbulence to explore multiscale coupling between streamlines and magnetic field line topologies, turbulent cascade rate, and energy dissipation. Through gradient tensor geometric invariants, we investigate the interplay between large-scale fluid dynamics and small-scale dissipative phenomena. From an...
The photosphere-corona system is governed by magnetohydrodynamic (MHD) processes spanning multiple scales. Photospheric plasma turbulent convection continuously reconfigures magnetic field topology, while coronal plasma dynamics respond to the underlying magnetic boundary conditions. This plasma-magnetic coupling produces coronal holes (CHs)—regions where coronal plasma flows freely along open...
Astrophysical jets from supermassive black holes form large-scale radio sources extending hundreds of kiloparsecs, while micro-quasar jets powered by stellar-mass black holes remain confined to sub-parsec scales within the interstellar medium. Despite this disparity, both systems share key magneto-hydrodynamical properties: they are fast, low-density outflows propagating through a denser...
A robust and reliable vacuum degradation detection system is essential to identify leaks in the cryostat of superconducting tokamaks [1]. This Vacuum Monitoring System (VMS) must be able to function in the harsh environment encountered near superconducting magnets, while also measuring vacuum pressure as low as 2E-8 mbar, with a response time in the order of few seconds [2]. Commercial vacuum...
A novel 2D-2V time-splitting Vlasov-Poisson solver has been used to deduce the kinetic behavior of the propagation of high-frequency electrostatic plasma waves in an inhomogeneous electron background. More specifically, we have simulated, in a scenario of constant proton density, the effect of density holes, where a lack of electrons leads to an unbalanced charge. These regions have been...
Negative ion sources for neutral beam injectors of modern and future tokamak machines, rely on a certain number of cylindrical quartz tubes (drivers) surrounded by an RF coil, in order to create a quasineutral plasma through an inductive discharge. The number of drivers depends on the size of the negative ion source, with SPIDER, the baseline source for the ITER neutral beam injector,...
Knowing the chemical composition of samples is essential to science and beyond, so much so that chemical analysis facilities are widespread within government agencies, universities, and industry. One of the enduring needs within the scientific community has been a capability for in situ chemical analysis for routine use outside the traditional analytical laboratory. Such instrumentation must...
The theoretical and numerical modelling of fundamental kinetic processes in low collision plasmas is the oldest and most traditional research activity that the plasma theory team in Nancy began in the ‘60s, and which in the ‘80s led to the development of the first Eulerian and semi-Lagrangian Vlasov codes.
I will present a few of the recent research activities and results, carried out along...
P. Buratti (1, 2), E. Menegoni (3), V. Vittorini (1), M. Tavani (1), D. Borgogno (1), F. Pucci (1) and L. Foffano (1)
(1) INAF-IAPS Roma, via Fosso del Cavaliere 100, I-00133 Rome, Italy
(2) ENEA, NUC Department, via E. Fermi 45, 00044 Frascati, Italy
(3) ASI, via del Politecnico, Roma
Magnetic reconnection in collisionless current layers embedded in tenuous background plasmas is...
The study of solar flares offers a unique laboratory for investigating high-energy plasma physics and magnetic reconnection processes. A central open question in solar physics concerns the mechanisms responsible for particle acceleration during the impulsive phase of flares. While magnetic reconnection is identified as the primary energy release trigger, the specific processes accelerating...
The integrated experiment Plasma4beam2 addresses some innovative experiments in accelerator physics, in part described in this work. In neutral beam injectors (NBI) for tokamak heating or diagnostics, radiofrequency (RF) negative ion sources are used and residual ion beams (both H+ and H-) are produced; recovering their energy may improve net NBI efficiency and reduce heat load on walls....
Understanding plasma turbulence in curved spacetime — especially near compact objects — remains an open challenge. Conventional analyses rely on flat-spacetime techniques that cannot fully capture the effects of strong gravitational curvature. In this work, we review a recent method for studying turbulence in generic manifolds and arbitrary gravitational fields, enabling the calculation of...
Questo lavoro studia la ionizzazione dei propellenti atmosferici in plasmi accoppiati induttivamente (ICP). Nasce dall’interesse di approfondire la comprensione della chimica del plasma atmosferico per l’applicazione a sistemi di propulsione elettrica air-breathing (ABEP) per satelliti operanti in orbite terrestri molto basse (VLEO). Queste orbite, che vanno da 100 a 350 km di altitudine,...
Operare piattaforme satellitari in un’orbita terrestre molto bassa (Very Low Earth Orbit - VLEO), a un’altitudine inferiore ai 400 km, offrirebbe vantaggi significativi sia in termini di prestazioni del carico utile sia di mitigazione dei detriti spaziali [1]. Tuttavia, la resistenza aerodinamica presente a queste altitudini, dovuta all’atmosfera residua, deve essere compensata continuamente...
Understanding the dynamics of small-scale magnetic fields in the solar
photosphere is essential for interpreting the physical processes
occurring in the upper layers of the solar atmosphere, where magnetic
coupling drives chromospheric and coronal activity. In this work we
present an improved simulation framework designed to investigate the
statistical properties of magnetic-loop...
Since the early studies of extragalactic jets (collimated flows of relativistic plasmas), a central question has persisted: how far can such jets propagate in space? The discovery of the 4.1 mega-parsec (Mpc) jet in the radio galaxy 3C-236 in 1974 set the benchmark for decades, later surpassed by J1420-0545 (radio galaxy with a jet extending to 4.69 Mpc) discovered in 2008. For a long time,...
Simulations of relativistic plasmas traditionally focus on the dynamics of two-species mixtures of charged particles under the influence of external magnetic fields and those generated by particle currents. However, the extreme conditions of astrophysical plasmas near compact objects, such as black holes and neutron stars, are often characterized by mixtures of electrons, protons, and...
By using results from a 3D hybrid simulation we investigate the properties of plasma turbulence at ion scales, focusing on how the bulk-kinetic and magnetic energy is transferred into the internal energy of the particles by the pressure-strain interaction term. We analyze the time evolution of the internal and kinetic energy as well that of the pressure strain. The last exhibits a substantial...
Abstract:
Over the last decades, electric propulsion (EP) technologies have been playing a crucial role in the space market due to their ability to achieve higher specific impulse compared to chemical thrusters, resulting in improved propellant mass economy [1]. Although many EP thrusters are now highly mature, their lifetime is limited by plasma-induced erosion of critical components, such...
The energy cascade in Alfvénic solar wind turbulence is often analyzed under the ideal plasma approximation, where viscosity (ν) and resistivity (η) are assumed equal and negligible. Recent observations, however, indicate that viscous effects associated with velocity fields may operate on scales significantly larger than those of magnetic dissipation. To address this, we introduce a...
F. Spadoni1,§, S. Perina1,∗, G. Castellani3, P. Tosi1, P. Fornasiero3, V.M. Sglavo2 and L.M. Martini1
1 University of Trento, Department of Physics, Trento, Italy
2 University of Trento, Department of Industrial Engineering, Trento, Italy
3 University of Trieste, Department of Chemical and Pharmaceutical Sciences, CNR-ICCOM, CENMAT, Trieste, Italy
§Present address: Dutch Institute for...
Young supernova remnants are ideal sites for studying the acceleration and transport of high-energy particles. This work presents a comprehensive investigation of particle acceleration in Cassiopeia A using spatially resolved X-ray observations, and explores how the surrounding circumstellar medium affects the acceleration efficiency. Radial intensity profiles of bright nonthermal X-ray...
The Bimodal Ammonia Nuclear Thermal and Electric Rocket (BANTER) project, funded by the European Innovation Council, aims to develop a versatile nuclear propulsion system for deep-space missions. Unlike conventional bimodal systems, which use separate propellants for nuclear thermal and nuclear electric propulsion, BANTER employs ammonia (NH₃) as a single propellant. This unified approach...
In the frame of non-equilibrium discharge processing for CO2 valorization and nitrogen fixation, nanosecond repetitively pulsed (NRP) discharges have shown a promising set of performances [1]. A modelling attempt must address microscopic time/space-resolved description of the physics and kinetics of the discharge. To this end, Particle-in-Cell (PIC) models seem to be the only option. The...
The custom Particle-in-Cell code we are developing for the study of Electron Cyclotron Resonance Ion Sources (ECRIS) has reached a version that reproduces various experimental observations. It also explained why the HSMDIS[1] magnetic configuration shows no erosion of the Boron-Nitride disks. The code reproduces the plasma formation from an empty plasma chamber to a density of the order of...
Geomagnetic field reversal sequences exhibit inter-reversal, or persistence, times spanning a broad range, from a few 10⁴ years to superchrons lasting more than 10⁷ years. Statistical analyses show that the reversal sequence does not follow a simple Poisson process with a constant rate and displays signatures of memory, clustering, and heavy-tailed behaviour. Short persistence times display...
Coronal mass ejections (CME)-driven shocks are the most efficient accelerators of gradual solar energetic particles (SEPs), which pose risks to technological infrastructure and human activity in space. Knowing the physical properties of expanding shocks is critical in order to prevent SEPs hazard and to understand their impact to the near-Earth environment. However, a thorough picture on how...
Magnetic reconnection (MR) offers a potential pathway toward high–specific impulse plasma acceleration for advanced electric propulsion. We present ongoing work on an MR-based thruster concept in which multiple flux ropes are generated by hollow cathodes inside a magnetized discharge chamber and guided by a set of coaxial coils. The aim is to exploit kink-unstable dynamics and the associated...
Young supernova remnants (SNRs) are natural laboratories where collision-less shock physics, magnetic-field amplification, and particle acceleration operate under plasma conditions inaccessible on Earth.
Thanks to imaging X-ray polarimetry, IXPE provides, for the first time, a direct probe of the magnetic-field geometry and turbulence level within the narrow synchrotron rims that trace the...
The study of astrophysical plasma in relativistic jets provides a unique laboratory for exploring high-energy particle acceleration and radiative processes. We investigate the multi-wavelength variability of blazar 3C 454.3, one of the most active extragalactic AGNs, monitored by the AGILE and Fermi satellites since 2007. In leptonic jet-emission scenarios, the optical emission arises from...
Plasma turbulence is an inherently multi-scale phenomenon that spans a vast range of spatial and temporal scales. In the solar wind, the inertial-range turbulent cascade extends over nearly four decades in length (from injection scales down to ion characteristic scales), and six decades when including electron characteristic scales. Being able to self-consistently simulate such a dynamics is...
The problem of particle acceleration at interplanetary (IP) shocks is long-standing, since several unresolved issues are still debated, pushing the research on this field
to jointly explore spacecraft in-situ observations, numerical simulations, and analytical models.
In this work, we analyze several shock crossings by spacecraft in the interplanetary space in order to link the shock and...
Turbulence in plasmas involves a complex cross-scale coupling of fields and distortions of particle velocity distributions, with the generation of non-thermal features. How the energy contained in the large-scale fluctuations cascades all the way down to the kinetic scales, and how such turbulence interacts with particles, remains one of the major unsolved problems in plasma physics. Moreover,...
Supernovae explosions (SNe) are among the most energetic events in
the Universe. They represent an instantaneous release of energy of about 10$^{51}$ erg, associated to the catastrophic collapse of a massive star or to a runaway nuclear burning on the surface of a white dwarf. Following the explosion, the ejected material expands into the interstellar medium (ISM), forming a Supernova Remnant...
The study of the statistics of gradient tensors’ invariants is useful to characterize the morphological and topological features of magnetic flux and plasma streamlines in turbulent space plasmas. In the recent past some studies of the statistics of the gradient tensors’ invariants have been performed to investigate the velocity and magnetic field flow lines topologies in turbulent...
Non-equilibrium velocity distributions with enhanced suprathermal tails are ubiquitous in space plasmas and are commonly described using kappa-type distributions. However, multiple kappa formulations coexist in the literature, leading to ambiguity in the definition of temperature and thermodynamic parameters and complicating their physical interpretation.
In this work, we present a unified...
Ionized Physical Vapour Deposition (iPVD) is a key plasma-based technology used across several sectors, from semiconductor manufacturing to protective coatings and energy applications [1]. Among iPVD methods, High Power Impulse Magnetron Sputtering (HiPIMS) is particularly attractive due to the peculiar plasma conditions it generates, enabling dense, adherent and finely structured coatings...
It was shown that pair luminosity of the newborn strange star with temperature of $10^{10}$ K may be as high as $10^{52}$ erg/s. The question remains: can a strange star maintain such a high surface temperature for a long time? To answer this question we studied thermal evolution of newborn strange star taking into account thermal conductivity of free quarks and neutrino emission by the URCA...
Recent advances in the space sector have led to new improvements in propulsion capabilities for the next generation space missions. Foreseen interplanetary missions such as the Cislunar space stations, cargo missions to Mars, and possibly human exploration of Mars call for novel, more advanced propulsion systems, with Electric Propulsion (EP) systems playing a significant role in this scenario...
Partial discharges (PDs) are among the main degenerative phenomena affecting electrical components in power networks. Several configurations can lead to PDs (Corona, Dielectric Barrier Discharges, Surface Discharges, etc); however, their key ingredients typically include the formation of a low-temperature, weakly ionized plasma, caused by a strong electric field, that interacts with a...
Burning plasmas in fusion reactors are complex systems where energetic particles (EP) play a fundamental role in cross-scale interactions [1]. This study reviews phase space zonal structures (PSZS) [2-5] and their significance in transport analyses. Using synthetic diagnostics from the HMGC and ORB5 codes [6,7], we illustrate the role of PSZS in capturing transport dynamics in burning plasmas...
Magnetic clouds are multi-scale structures: coronal flux ropes evolve to become as wide as 0.2 AU near the Earth; their magnetic fields vary on scales smaller than their average size, and present turbulent fluctuations. We perform high resolution 2.5D MHD simulations to study a magnetic flux rope cross section in the expanding solar wind together with turbulence: we investigate how turbulence...
Gyrotrons are essential devices for electron cyclotron resonance heating (ECRH) in magnetic fusion reactors, and need to deliver MW-level power continuously and reliably. However, experiments have revealed that undesired trapped electrons in the magnetron injection gun (MIG) region, can cause to internal damages due to arcs, and large electron currents that its power supplies cannot withstand....
