Browsing by Author "Laricchiuta, Annarita"

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    Elementary processes and kinetic modeling for hydrogen and helium plasmas
    (Basel : MDPI, 2017) Celiberto, Roberto; Capitelli, Mario; Colonna, Gianpiero; D’Ammando, Giuliano; Esposito, Fabrizio; Janev, Ratko; Laporta, Vincenzo; Laricchiuta, Annarita; Pietanza, Lucia; Rutigliano, Maria; Wadehra, Jogindra
    We report cross-sections and rate coefficients for excited states colliding with electrons, heavy particles and walls useful for the description of H2/He plasma kinetics under different conditions. In particular, the role of the rotational states in resonant vibrational excitations of the H2 molecule by electron impact and the calculation of the related cross-sections are illustrated. The theoretical determination of the cross-section for the rovibrational energy exchange and dissociation of H2 molecule, induced by He atom impact, by using the quasi-classical trajectory method is discussed. Recombination probabilities of H atoms on tungsten and graphite, relevant for the determination of the nascent vibrational distribution, are also presented. An example of a state-to-state plasma kinetic model for the description of shock waves operating in H2 and He-H2 mixtures is presented, emphasizing also the role of electronically-excited states in affecting the electron energy distribution function of free electrons. Finally, the thermodynamic properties and the electrical conductivity of non-ideal, high-density hydrogen plasma are finally discussed, in particular focusing on the pressure ionization phenomenon in high-pressure high-temperature plasmas.
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    QDB: A new database of plasma chemistries and reactions
    (Bristol : IOP Publ., 2017) Tennyson, Jonathan; Rahimi, Sara; Hill, Christian; Tse, Lisa; Vibhakar, Anuradha; Akello-Egwel, Dolica; Brown, Daniel B.; Dzarasova, Anna; Hamilton, James R.; Jaksch, Dagmar; Mohr, Sebastian; Wren-Little, Keir; Bruckmeier, Johannes; Agarwal, Ankur; Bartschat, Klaus; Bogaerts, Annemie; Booth, Jean-Paul; Goeckner, Matthew J.; Hassouni, Khaled; Itikawa, Yukikazu; Braams, Bastiaan J; Krishnakumar, E.; Laricchiuta, Annarita; Mason, Nigel J.; Pandey, Sumeet; Petrovic, Zoran Lj.; Pu, Yi-Kang; Ranjan, Alok; Rauf, Shahid; Schulze, Julian; Turner, Miles M.; Ventzek, Peter; Whitehead, J. Christopher; Yoon, Jung-Sik
    One of the most challenging and recurring problems when modeling plasmas is the lack of data on the key atomic and molecular reactions that drive plasma processes. Even when there are data for some reactions, complete and validated datasets of chemistries are rarely available. This hinders research on plasma processes and curbs development of industrial applications. The QDB project aims to address this problem by providing a platform for provision, exchange, and validation of chemistry datasets. A new data model developed for QDB is presented. QDB collates published data on both electron scattering and heavy-particle reactions. These data are formed into reaction sets, which are then validated against experimental data where possible. This process produces both complete chemistry sets and identifies key reactions that are currently unreported in the literature. Gaps in the datasets can be filled using established theoretical methods. Initial validated chemistry sets for SF6/CF4/O2 and SF6/CF4/N2/H2 are presented as examples.