Gas discharges

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 therefore modelled by kinetic approaches: polynomial expansion, state-to-state and particle-based (Particle-in-Cell, Monte Carlo and Molecular Dynamics) methods.

gas discharges

Low- & High-Pressure Electric Discharges

In many technological plasmas formed in electrical discharges, the onset of non-equilibrium conditions significantly affect the EEDF (electron energy distribution function) determining large deviation from Maxwell distribution. The shape of the EEDF depends not only on the gas composition, but also on the level distribution. The synergy between electrons and excited states is investigated by a self-consistent approach, instead of the common assumption electron-impact process rates depending only on the applied reduced electric field (E/N). Self-consistent model demonstrate a very large impact in the post-discharge phase (E/N=0), where excited states transfer energy to free electrons through superelastic collisions, creating pronounced structures in the EEDF as peaks and plateaux.

Different gas discharge configurations (DC glow, DBD, RF capacitive and inductive, MW and helicon discharges) have been studied using multidimensional Particle-in-Cell/Monte Carlo Collisional (PIC-MCC) approach [1, 2]. The methodology allows the characterization of plasma-gas dynamics and kinetics in the self-consistent electromagnetic field taking into account volume and surface processes. Self-organized structures and non-equilibrium effects of electron distribution function, ion distribution function, molecular vibrational distribution function and production of hot atoms have been detected in the different cases. The same numerical technique has been applied to model zoomed region of the different discharges studied (sheath regions in ExB glow discharges, plume expansion, extraction region in RF-inductive negative ion source) and experimental diagnostic methods (electrostatic probe, laser photodetachment).

CO2 Destruction

The plasma assisted conversion of greenhouse gases, such as CO2, is collecting a large interest in the community both for its scientific relevance and also for technological applications in energetic and environment fields. CO2 dissociation is the first step in the global conversion process. Discharge mechanisms that promote dissociation through vibrational excitation can maximize the energy efficiency of the conversion.
This is a new research line and the results, due to their relevance in the modeling community, have been published as a Fast Track Communication in the Plasma Sources Science and Technology Journal

Nucleation and growth of nanoparticle in plasma

Laser ablation of solids in liquids is considered a very efficient technique for the synthesis of nanocrystals. The most important feature is the extreme confinement effect of liquid, i.e., the liquid restricts the expansion of the plasma plume. The extreme confined conditions and induced high-pressure region favor the formation of unusual metastable phases. These advantages allow the designer to combine selected solid targets and liquid to fabricate compound nanostructures with desired functions. The kinetic approach to model the nanoparticle nucleation and growth is based on the explicit sequential nanoparticle charging, ion adhesion and atom evaporation as the nanoparticle grows and as the plasma parameters (density and temperature) in which it is immersed change. Particle-based numerical models has been chosen to simulate this process

Facilities & Labs

HPC Cluster and Services @ Bari

People

Fracnesco_tacccognaFrancesco

Taccogna

CNR Researcher

Pierpaolo_minelliPierpaolo

Minelli

CNR Researcher

ldpietanzaLucia Daniela

Pietanza

CNR Researcher

gcolonnaGianpiero

Colonna

CNR Researcher

savino_longoSavino

Longo

Associate Professor

mcapitelliMario

Capitelli

Associate Professor

Publications

  1. N. Oudini, N. Sirse, F. Taccogna, A. R. Ellingboe and A. Bendib, Photo-detachment signal analysis to accurately determine electronegativity, electron temperature, and charged species density, Appl. Phys. Lett. 109, 124101 (2016); doi: 10.1063/1.4963138
  2. L. D. Pietanza, G. Colonna, V. Laporta, R. Celiberto, G. D’Ammando, A. Laricchiuta, and M. Capitelli, Influence of Electron Molecule Resonant Vibrational Collisions over the Symmetric Mode and Direct Excitation-Dissociation Cross Sections of CO2 on the Electron Energy Distribution Function and Dissociation Mechanisms in Cold Pure CO2 Plasmas, J.Phys. Chem. A, 120 (2016) 2614–2628, Doi: 10.1021/acs.jpca.6b01154
  3. L. D. Pietanza, G. Colonna, G. D’Ammando, A. Laricchiuta, M. Capitelli, Non equilibrium vibrational assisted dissociation and ionization mechanisms in cold CO2 plasmas, Chem. Phys. 468 (2016) 44, Doi: 10.1016/j.chemphys.2016.01.007
  4. L. D. Pietanza, G. Colonna, G. D’Ammando, A. Laricchiuta, M. Capitelli, Electron energy distribution functions and fractional power transfer in “cold” and excited CO2 discharge and post discharge conditions, Phys. Plasmas, 23 (2016) 013515  Doi: 10.1063/1.4940782
  5. G. Colonna, V Laporta, R Celiberto, M Capitelli and J Tennyson, Non-equilibrium vibrational and electron energy distributions functions in atmospheric nitrogen ns pulsed discharges and μs post-discharges: the role of electron molecule vibrational excitation scaling-laws, Plasma Sources Science and Technology, 24 (2015) 035004,  Doi: 10.1016/j.chemphys.2016.01.007
  6. G. D’Ammando, G Colonna, M Capitelli and A Laricchiuta, Superelasticcollisions under low temperature plasma and after glow conditions: A golden rule to estimate their quantitative effects, Phys. Plasmas 22 (2015) 034501, Doi: 10.1063/1.4913670
  7. M. Capitelli, G. Colonna, G. D’Ammando, V. Laporta, A. Laricchiuta, Non equilibrium dissociation mechanisms in low temperature nitrogen and carbon monoxide plasmas,ChemicalPhysics 438 (2014) 31-36, Doi: 10.1016/j.chemphys.2014.04.003
  8. M. Capitelli, G Colonna, G D’Ammando, V Laporta and A Laricchiuta, The role of electron scattering with vibrationally excited nitrogen molecules on non-equilibrium plasma kinetics, Phys. Plasmas 20 (2013) 101609, Doi: 10.1063/1.4824003
  9. F. Taccogna, Non-classical plasma sheaths: space-charge-limited and inverse regimes under strong emission from surfaces, Europ. Phys. J. D 68(7), 199-206, (2014); ISNN: 1434-6060; doi: 10.1140/epjd/e2014-50132
  10. M. Capitelli, I. Armenise, E. Bisceglie, D. Bruno, R. Celiberto, G. Colonna, G. D’Ammando, O. De Pascale, F. Esposito, C. Gorse, V. Laporta, A. Laricchiuta, Thermodynamics, Transport and Kinetics of Equilibrium and Non-Equilibrium Plasmas: A State-to-State Approach, Plasma Chemistry and Plasma Processing 32 (2012 427),doi:10.1007/s11090-011-9339-7

Projects

MWPECVD: Microwave Plasma Enhanced Chemical Vapor Deposition – Progetto Strategico ATS PS_136 (2007 – 2010)

Progetto Partenariati Regionali per l’Innovazione – PUGLIA Fesr (2007-2013)

APULIA SPACE: Esperti nell’uso di tecnologia abilitanti nel settore dello spazio,  PON03PE_00067_6, (2014-2016)

Latest News

Disordered serendipity: a glassy path to discovery

A workshop in honour of Giorgio Parisi’s 70th birthday

September 19-21, 2018 - Roma

Sapienza University

With the occasion of celebrating Giorgio Parisi 70th birthday, the conference "Disordered serendipity: a glassy path to discovery" brings to Rome many among the world-leading experts in the field of complex systems. In order to properly represent the many fields of research where Giorgio Parisi gave a relevant contribution in his studies of disordered systems, the conference covers a broad spectrum of topics: from  fundamental and rigorous analysis of the statistical mechanics of disorder systems to applications in biology and computer science. These subjects are deeply interconnected since they are characterized by the presence of glassy behavior.

 

https://sites.google.com/site/disorderedserendipity/

Il prof. Giorgio Parisi eletto presidente dell'Accademia dei Lincei

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La più antica accademia del mondo ha un nuovo Presidente

Roma, 22 Giugno 2018

Siamo lieti di annunciare che il prof Giorgio Parisi, fisico della Università La Sapienza di Roma e Associato Cnr Nanotec, è il nuovo Presidente dell'Accademia Nazionale dei Lincei. A lui le nostre più vive congratulazioni e gli auguri di buon lavoro.

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Costituzione del nuovo Ispc-Cnr

IV incontro - nuovo Istituto di Scienze del Patrimonio Culturale - CNR

Lecce, 20 aprile 2018

Aula Rita Levi Montalcini - ore 11:00

CNR NANOTEC c/o Campus Ecotekne

Per comunicazioni inerenti il processo di riorganizzazione potete scrivere a: infonuovoispc@cnr.it

Tutte le informazioni che riguardano gli incontri, compresi gli indirizzi dello streaming, li trovate sul sito http://www.ispc.cnr.it

Informazioni logistiche: goo.gl/ZieUad