C. Catalfamo

Effect of electronic excited states on transport in magnetized hydrogen plasma

Multicomponent diffusion coefficients for magnetized, equilibrium hydrogen plasma have been calculated. The equilibrium composition of the plasma is determined by taking consistently into account the number of allowed atomic electronic excited states (EES) as determined by the average interparticle distance. The coefficients are shown to depend on the inclusion of realistic cross sections for the interactions with EES. The effect of an applied magnetic field on the diffusion coefficients and on derived quantities like the electrical conductivity and the internal and reactive thermal conductivity is studied and explained.

Convergence of Chapman-Enskog calculation of transport coefficients of magnetized argon plasma

Convergence properties of the Chapman-Enskog method in the presence of a magnetic field for the calculation of the transport properties of nonequilibrium partially ionized argon have been studied emphasizing the role of the different collision integrals. In particular, the Ramsauer minimum of electron-argon cross sections affects the convergence of the Chapman-Enskog method at low temperature, while Coulomb collisions affect the results at higher temperatures. The presence of an applied magnetic field mitigates the slow convergence for the components affected by the field.

Transport Properties of High-Temperature Jupiter-Atmosphere Components

Transport properties of high-temperature helium and hydrogen plasmas as well as Jupiter atmosphere have been calculated for equilibrium and nonequilibrium conditions using higher approximations of the Chapman–Enskog method. A complete database of transport cross sections for relevant interactions has been derived, including minority species, by using both ab initio and phenomenological potentials. Inelastic collision integrals terms, due to resonant charge-exchange channels, have been also considered.

Transport of internal electronic energy in atomic hydrogen thermal plasmas

Reactive and internal thermal conductivities for equilibrium hydrogen plasma have been calculated by the Chapman-Enskog method. The equilibrium composition of the plasma is determined by taking consistently into account the number of allowed atomic electronic excited states (EES) as determined by the average interparticle distance. The coefficients depend on the inclusion of realistic cross sections for the interactions with EES. In particular, the interplay between the two coefficients that describe the transport of electronic and ionization energy is analyzed.

Thermodynamics and transport properties of thermal plasmas: the role of electronic excitation

The role of electronic excited states in affecting the thermodynamic and transport properties of thermal plasma is investigated in the temperature range [300‐100 000 K] and in the pressure range [1‐10 3 atm] for hydrogen and [10 −2 ‐10 3 atm] for nitrogen. Thermodynamic functions have been calculated modelling in different ways the electronic levels of atomic species (ground-state, Debye‐H¨ uckel and confined-atom approximations). Frozen and reactive specific heats as well as isentropic coefficients are strongly affected by the electronic excitation whereas compensation effects smooth its influence on the total specific heat, i.e. the sum of frozen and reactive contributions. Higher-order approximations of the Chapman‐Enskog method have been used to evaluate transport coefficients, including electronically excited states as separate species. The importance of a state-to-state approach to calculate transport coefficients is presented taking into account the strong dependence of transport cross sections on the principal quantum number. Results for hydrogen, nitrogen and air plasmas are widely discussed.

Cutoff criteria of electronic partition functions and transport properties of atomic hydrogen thermal plasmas

Transport coefficients of equilibrium hydrogen plasma have been calculated by using different cutoffs of electronic partition functions and different sets of transport cross sections of electronically excited states. The selection of both the cutoff criterion and transport cross sections deeply affects the transport coefficients of the H, H+, e plasma mixture in the temperature range of 10 000–50 000 K and in the pressure interval of 1–1000 atm.

Transport properties of high-temperature air in a magnetic field

Transport properties of equilibrium air plasmas in a magnetic field are calculated with the Chapman–Enskog method. The range considered for the temperature is [50–50 000] K and for the magnetic induction is [0–300] T.

The Role of Electronically Excited States on Transport Properties of Air Plasmas

Transport coefficients of an LTE air plasma are derived in the framework of the ChapmanEnskog theory, including the effect of low-lying excited states of oxygen and nitrogen atoms and ions. Elastic collision integrals for interaction involving excited species are calculated referring to a phenomenological approach, successfully applied to ground-state components of planetary atmospheres. The inelastic contribution, affecting odd-order collision integrals, is estimated from relevant resonant charge and excitation exchange processes for atom-parent-ion and atom-atom collisions respectively.