The Topical Issue collects original papers originating from the presentations at the International Conference on Atomic and Molecular Data and Their Applications (ICAMDATA), a continuing series of international conferences that promotes the use of atomic and molecular (AM) data in various fields of science and technology, providing a forum for interaction of AM data producers and users and for information exchange on AM data needs and availability, and fostering the cross-disciplinary cooperation between the AM data producers and users and the coordination of AM data activities and databases worldwide.

The Binary-Encounter Bethe approach was applied to the estimation of total ionization induced by electron impact in metastable states of diatomic molecules. The cross sections recently obtained for N2 and CO are reviewed and the new results for H2 are presented, discussing their reliability through the comparison with other theoretical methods.

The cross sections for the two-step process, represented by the electron-impact vibro-electronic excitation X-1 Sigma(+)(v) -> A(1)Sigma(+)(v") of the LiH molecule, followed by radiative decay back on the vibrational manifold of the ground state, A(1)Sigma(+)(v") -> X-1 Sigma(+)(v'), are calculated as a function of the incident electron energy from the threshold to 1000 eV. The final cross sections for the two-step process, which results in an overall vibrational excitation of the molecule, known also as E-v process, are provided for all the possible v, v' transitions among the vibrational levels, including the continuum, of the electronic ground state.

This topical review gathers the last updates concerning caesium-free negative ion sources presented during the 63 rd Course of the International school of Quantum Electronics of the Ettore Majorana Foundation and European collaborative works related to these lectures. Hence, beyond the frame of this course this topical review addresses both theoretical and experimental work performed during these last few years and complexities represented by the conception of a negative ion source ranging from the creation of negative ions to their neutralization.

Electron-impact cross sections for the v->V'transitions between the vibrational levels of X ? and A ? electronic states of the LiH molecule, are calculated from threshold to 1000 eV by using the threshold-modified Massey-Mott approximation. The rate coefficients for the same transitions are also calculated in the range 0.1-1000 eV. Scaling relationships for both the v - v? cross section and v - v? rate coefficients are derived, allowing us to represent the calculated quantities in a compact analytic form.

The thermodynamic and transport properties of weakly non-ideal, high-density partially ionized hydrogen plasma are investigated, accounting for quantum effects due to the change in the energy spectrum of atomic hydrogen when the electron-proton interaction is considered embedded in the surrounding particles. The complexity of the rigorous approach led to the development of simplified models, able to include the neighbor-effects on the isolated system while remaining consistent with the traditional thermodynamic approach. High-density conditions have been simulated assuming particle interactions described by a screened Coulomb potential.

Electron energy distribution function, vibrational and electronic excited states are self-consistently solved to investigate the formation of ammonia under nano-second repetitive pulsed discharges. The inclusion of transitions starting from electronically and vibrationally excited states of N-2 and H-2 molecules in the electron Boltzmann equation is discussed to rationalize the evolution of the electron energy and level distributions, as well as of chemical composition. The results are presented focusing on the dependence of the vibrational distributions of both N-2 and H-2 molecules and eedf on the applied reduced electric field. The relevance of using complete sets of electron impact cross sections, including transitions from vibrationally excited states has been investigated, comparing with the ground state model.

A state-to-state self-consistent model of the Hydrogen-Helium mixture has been applied to investigate the ionization kinetics during the entry of a capsule in the atmosphere of a gaseous giant planet. The kinetic model has been coupled with the 1D shock tube code to compare theoretical results with the measurements obtained in the EAST facility at NASA-AMES. The alternate path to ionization proposed results in a more efficient production of electrons, in agreement with the experiments. (C) 2020 Elsevier Ltd. All rights reserved.

This chapter gives an overview of the different scientific aspects of meteoroids entering physics, a subject of continuous interest either to understand the relevant fluid-dynamics phenomenology or to study the composition of the fragments coming from the meteoroid-earth impact containing primordial elements characterizing the life of the universe.

The entry of meteoroids into the Earth's atmosphere at high speeds produces a bow shock wave and the high temperatures in the shock layer induce an intense heat flux that melts and vaporizes the body. The shock is then structured in two regions: the 'ablation layer' close to the meteoroid surface and constituted by a vapor in equilibrium with the liquid film at the meteoroid surface, and the air shock layer, separated by an interface, whose thickness depends on the meteoroid's dimensions and its entry conditions (velocity and altitude). Across the layer the temperature changes from around 3000 K at the surface of the body to about 20 000 K at the interface [1], reaching very high temperatures at the shock front. Any chemical model of meteoric ablation [1-3] should accurately characterize the ablation layer and the interface, deriving the equilibrium composition, the thermodynamic properties and also the transport coefficients for the estimation of the flow characteristics during hypersonic entry, such as friction and surface heat load. The model should describe the transition between the vapor layer, the composition reproducing the elemental fractions characteristic of the meteoroid, and the interface region, where the complexity of the chemistry increases due to the mixing with air components and the properties of the resulting plasma depend on the fraction of the ablated species in the mixture. The chemical and mineralogical nature of the meteorites (chapter 5) is the basis of their classification and indicates that for chondrites (stony meteorites) the most abundant phases are silicates, producing a differential ablation profile (see figure 4.2 of chapter 4) that shows the dominant ablation of Si, Fe and Mg at an altitude of around 90 km. In this chapter recent efforts to derive accurate thermodynamic and transport properties of silicon compounds, SiO2 or SiC, regarded as models for chondriticmeteorites, are reported and the role of ablated silicon species in affecting the properties of air is also investigated, allowing a description of the interface region. The properties are calculated in a wide range of temperatures [3 × 103-5 × 104 K], i.e. using as lower limit the temperature at the melting surface of the meteoroid body. Advanced chemical models are considered, including molecular species such as C3, O3, Si2, Si3, Si2N, SiN, NO2, ..., potentially minority species but in some cases important at low temperatures, and also molecular positive and negative ions. The multiply charged atomic ions are included up to the fourth ionization level to ensure the soundness of results for high temperatures, where the plasma is fully ionized. The calculations are performed with the web-access EquilTheTA tool [4] and core databases, accessed by thermodynamic and transport computational modules, collecting physical-chemical data and transport cross sections for atomic and molecular species. These databases have been extended to include accurate internal partition functions of atomic and molecular silicon-based species and binary collision dynamical information for interactions involving silicon-carbon, silicon- oxygen and silicon-nitrogen compounds. The thermodynamic and transport properties of plasmas containing silicon-based chemical components represent fundamental information, not only for the simulation of meteoroid thermal ablation during atmosphere entry, but also for the experimental investigation of meteorites. In fact, the composition of the plasma formed in laser-ablation techniques allows, under the assumption of local thermodynamic equilibrium, the reconstruction of synthetic emission spectra that are useful for the elemental analysis of meteorites as well as terrestrial rocks [5-7] through a calibration-free approach [8]. Furthermore, this knowledge offers theoretical support for the design of ablative thermal protection systems for space vehicles [9, 10], as well as arc welding [11] for the production of silica powder.

This chapter is intended to give a compendious and comprehensive account of the theoretical description of electron-molecule interactions in molecular plasmas. We will briefly review the existing theoretical cross section data characterizing the electron-impact with molecules of interest in meteoroid and spacecraft entry physics.

Large attention is nowadays devoted to the understanding of the activation of CO2 by cold plasmas in different conditions such as microwave (MW), dielectric barrier (DBD) or nano-repetitively pulsed (NRP) discharges. Theoretical efforts are being developed to better understand the electrical conditions necessary for maximizing the CO2 dissociation process [1-7]. In particular, Bogaerts et al. [1-2] concentrated their efforts on the vibrational plasma kinetics, while Pietanza et al. [3-7] devoted particular attention to the development of the electron energy distribution function (EEDF) in pure CO2 and CO plasmas. In this contribution, we present new results for MW CO2 reacting mixture, obtained by applying a self-consistent kinetic model, emphasizing the role of CO2 and CO electronically excited states (EESs) in affecting the EEDF. EESs play an important role in superposing structures in the EEDF especially in the post-discharge regime due to the action of superelastic collisions.

A joint experimental/theoretical investigation on the characteristics of argon plasmas produced in GyM magnetic linear device has been carried out, comparing the measured electron energy distribution function (EEDF) with the distribution resulting from a self-consistent state-to-state kinetic model coupling the chemistry of inelastic and reactive collisional processes with the Boltzmann equation for free electrons. A preliminary comparison between the theoretically simulated and experimentally measured electron temperature shows a reasonable agreement.

Collection of different research activities on detection measurements and modeling of meteoroid.

Abstract: The experimental investigation of range and strength of the intermolecular interaction in some prototypical systems has been carried out with the molecular beam technique. The data analysis suggested the adoption of a phenomenological approach, useful to formulate the force fields in systems at increasing complexity and whose details required in several applications, including the description of transport phenomena, are difficult to extract from only standard theoretical methods. The phenomenological approach is here presented, reviewing the results obtained in the derivation of collision integrals relevant to the estimation of transport properties for plasmas of applied interest.

The influence of the internal energy content, either vibrational or electronic, on the probability of CO elementary processes induced by electron-impact is investigated. In particular the vibronic excitations of the first singlet state of the CO spectrum, A(1)Pi, are derived in the framework of the similarity approach, characterizing also the radiative properties to the ground electronic state. Moreover the ionization of the ground state to the first three states of the molecular ion are calculated with the binary-encounter-dipole model, investigating the branching ratio of the three channels and their vibrational dependence. Finally the total ionization of the CO metastable a(3)Pi state is considered in the binary-encounter-Bethe approach.

The transition to breakdown of a weakly ionized gas, considering inverse bremsstrahlung, has been investigated using a state-to-state self-consistent model for gas discharges, mimicking a ns laser pulse. The paper is focused on the role of the initial ionization on the plasma formation. The results give the hint that some anomalous behaviors, such as signal enhancement by metal nanoparticles, can be attributed to this feature. This approach has been applied to hydrogen gas regarded as a simplified model for LIBS plasmas, as a full kinetic scheme is available, including the collisional-radiative model for atoms and molecules. The model allows the influence of different parameters to be investigated, such as the initial electron molar fraction, on the ionization growth.

The characterization of the thermodynamic and transport properties of plasmas including silicon species could be of great interest for the investigation of many different systems containing the product of the ablation of silicon-based materials. Different plasma systems (pure silicon, silicon-argon, silicon dioxide and silicon carbide) have been investigated in a wide temperature range (10(3) -4 10(4) K) and for different pressures (1, 10, 30 and 100 atm), relying on the construction of accurate and extended databases of internal energy levels and binary-interaction transport cross sections for the silicon compounds. The results have been compared with the available results in the literature also studying the dependence on the ratio of components.

The non-equilibrium vibrational distributions and electron energy distributions of CO in nanosecond repetitively pulsed discharges and afterglows have been determined from a coupled solution of the time-dependent Boltzmann equation for the electron energy distribution function (eedf) of free electrons, the master equations for vibrational levels of CO and the electronic excited states of CO, O and C atoms. The optically thick plasma conditions have been investigated in a companion paper (part I), while in the present paper we also show the results obtained by allowing radiative emission processes (optically thin plasma) as well as electronic excited state collisional quenching processes. Two case studies, which differ for the duration of the afterglow following each pulse (1 mu s and 25 mu s case studies) are discussed, and each pulse is characterized by a time-dependent electric field profile in the range 0-20 ns. The results, which depend on the number of pulses considered in the discharge and the corresponding afterglow duration, show several peaks in the eedf due to super-elastic electronic collisions. On the other hand, the quenching process of the a(3)Pi electronic state of CO determines the pumping of vibrational quanta in the nu = 27 level, which in turn largely modifies the vibrational distribution function (vdf) of CO. As a consequence, the quenching of the a(3)Pi state increases the reactivity of CO through the Boudouard reaction, and under given conditions, this channel can become more important than the dissociation rates by electron impact collisions.