ItalianoThis research area deals with theoretical modelling, experimental applications and diagnostics of plasma.
Elementary Processes in Plasmas are studied by accurate theoretical methods, relating to different classes of processes relevant to many technological fields, from thermonuclear controlled fusion (negative ion sources, divertor region in tokamak), to aerospace (re)entry conditions and astro-chemistry. Thermodynamic and transport properties in equilibrium plasmas have been calculated for complex gas mixtures, of different atmospheres (Earth, Mars and Jupiter). Space Plasmas are typically in very extreme conditions, from very low to very high density: this is the case of dusty plasmas, which deals with the dynamics of dust above airless body surfaces, rings and planet formation. Electric thrusters (Hall-effect and helicon discharges) and plasma-assisted combustion (SCRAMJET) are important for space transportation (satellite guidance, orbit transfer and deep space exploration).
The study of the temporal and spatial evolution of Laser Induced Plasma in different environments by spectroscopic techniques gives the required knowledge useful for a wide range of application fields (e.g. chemical analysis applied to environment, cultural heritage, space, material processing). Theoretical investigations have been also dedicated to verify the assumption of local thermodynamic equilibrium (LTE), commonly considered for calibration-free LIBS.
Plasma sources based on discharges created by direct current, capacitively coupled radiofrequency, inductively coupled radiofrequency and microwaves are characterized by thermal non-equilibrium condition and are modelled by kinetic approaches: polynomial expansion, state-to-state and particle-based (Particle-in-Cell, Monte Carlo and Molecular Dynamics) methods. These plasmas are studied from an experimental point of view, employing different optical techniques for Advanced Non-Equilibrium Plasma Diagnostics.
In particular Microwave Plasmas are employed successfully for the growth of undoped nanocrystalline (NCD) and polycrystalline diamond (PCD) films, deposited by a microwave PECVD (MWPECVD) technique starting from gas mixtures of CH4 highly diluted (less than 5%) in Ar and H2, respectively.
Plasma surface engineering includes a large area of processes aimed to drastically change the surface properties of materials preserving the bulk ones. The processes can be performed by using both low and atmospheric pressure plasmas, in both direct and remote approach, injecting the film precursors in gas, vapor and aerosol form.
