Elementary Processes in Plasmas are obtained at PLASMI Lab by accurate theoretical methods, accounting for the dependence on the excitation of internal degrees of freedom of atoms and molecules (rovibronic levels) and for the different classes of processes relevant to technological fields, from fusion applications (negative ion sources, divertor region in tokamak), aerospace (re)entry conditions and astrochemistry.
Atom-Molecule and Molecule-Molecule collisions
» atom-molecule collisions:
roto-vibrational energy exchange and dissociation
(v,j) = initial rotational and vibrational quantum numbers
(v’,j’) = final rotational and vibrational quantum numbers
- Method: quasiclassical trajectory method (QCT)
- In house numerical codes suitable for parallel, distributed (computational grids) and hybrid (MPI+OpenMP) calculations
- Typical serial computational time: from 6 months to 20 years Optimized for Fermi Supercomputer at Cineca
results and work in progress
N+N2(v,j), O+O2(v,j), N+O2(v,j), O+N2(v,j)
N2+N2, O2+N2 (molecule-molecule, even semiclassical)
»Nuclear fusion (negative ion sources, divertor):
H++H2(v,j) non-adiabatic, with charge transfer
He+H2(v,j), He+H2+(v,j), H+HeH+(v,j)
Electron – Molecule Collisions
Dynamics of electron-molecule collisions for resonant and non-resonant elementary processes:
»H2, O2, N2, NO and CO resonant vibrational excitation (RVE)
»H2, O2 dissociative attachment (DEA)
»O2 and N2 resonant dissociation
»H2 non-resonant excitation and dissociation
»O2 and N2 dissociative excitation
»O2 and N2 non-dissociative ionization
»BeH, Cs2 and CH non-resonant electronic excitation
The interaction of atoms and molecules with surfaces can lead to a great variety of physical and chemical processes including scattering, adsorption, atoms recombination and molecule dissociative adsorption.
Molecular Dynamic calculation of surface processes aims are:
Understanding the dynamics pathways underlying atom/molecule-surface interactions
Predicting the catalytic activity as a function of atomic/molecular properties and structural /chemical properties of the solid substrate
Determining an accurate database of collisional coefficients to be used in kinetic modelling of surface chemical processes
In addition it is possible to determine the influence on the reaction dynamics of:
» Surface Polymorph
» Surface Chemical Composition
» Surface Adsorption Site
» Surface Temperature
» Isotope Species
The phys4entry DB, designed and implemented by CNR IMIP Bari and SER&Practices spin-off of the University of Bari, is a database of state-selected dynamical information for elementary processes relevant to the state-to-state kinetic modeling of planetary-atmosphere entry conditions.
State-to-state approach, proposed in the 70’s by the plasma chemistry group in Bari and nowadays widely used by the international plasma modeling community, can be considered as the most accurate tool for the investigation of chemical and thermal non-equilibrium under different conditions.
In the state-to-state kinetics, chemical processes are studied determining at the same time the distributions of internal levels of atoms and molecules, also accounting for the self-consistent coupling with the free electron kinetics.
HPC Cluster and Services @ Bari