The thermo-chemical relaxation of nitrogen hypersonic flows behind strong shocks and in nozzle expansions is investigated with 1D flow simulations and detailed vibrational kinetics. This work aims at deriving from detailed vibrational models accurate reduced models easy to implement in multidimensional reentry flow codes. First, nonequilibrium couplings between vibrational excitation, dissociation and recombination reactions are considered. Vibrational kinetics is described using accurate vibrational state-to-state rate constant databases of the literature completed with the forced harmonic oscillator model. The key role of multiquanta vibration-translation processes on the relaxation of the vibrational distribution function and the dissociation/recombination processes is put forward behind shocks and in nozzles. The vibrational distributions, which deviate strongly from equilibrium for nozzle expansions, are driven by vibration-translation processes and dissociation/recombination processes. A macroscopic model using groups of vibrational levels is developed to derive consistently the chemical and vibrational energy source terms from the vibrational state-to-state database.This model successfully reproduces the thermal, chemical and vibrational distribution function dynamics predicted by the state-to-state model with one group of levels behind a shock wave, and with three groups of levels in nozzle expansions. In a second step, the detailed vibrational model is extended to ionized nitrogen flows, including in particular a detailed modeling of the resonant electronvibration processes. Behind shocks, these processes control the rate of ionization by feeding energy to the electrons, up until the time when the elastic electron-ion exchanges takes over. It is shown that the widely used assumption of equilibrium between the electron and vibration temperatures predicts a too fast relaxation behind shock waves. In nozzle expansions, it is shown that for low electron concentration, the electron temperature is driven by electronvibration processes. Moreover, it is found that electrons are strongly coupled to low vibrational levels, and that more levels are coupled when the electron temperature increases. Coupling of the flow field with radiation is performed using the tangent slab approximation, and it is shown that the population of a metastable and two higher electronic levels are strongly impacted. Finally, the macroscopic model is extended to ionized nitrogen flows and is successfully applied on shock waves with one group of levels and with three groups of levels in nozzle expansions. In particular, the proposed macroscopic model represents more accurately the electron-vibration coupling than the widely used Landau-Teller model.

Title: Recombination study of ions with electrons at temperatures below 300 K Author: Tomáš Kotrík Department: Department of Surface and Plasma Science Supervisor of the doctoral thesis: Prof. RNDr. Juraj Glosík, DrSc. Department of Surface and Plasma Science Abstract: Presented is the study of recombination of ions with electrons performed at low temperatures using the Flowing afterglow with Langmuir probe experimental technique. Studied was the dissociative recombination of H and D ions at temperatures 77 - 300 K. Apart from a two-body also a three-body recombination channel assisted by neutral He atoms was identified and studied. The obtained temperature dependence of the two-body recombination rate coefficient is in a good agreement with findings of other experimental and theoretical works. The dissociative recombination of HCO and DCO ions with electrons was studied in the temperature range 150 - 300 K. The observed temperature dependence of measured recombination rate coefficient for HCO and DCO ions (~T -1.3 and ~T -1.1 , respectively) is in agreement with the majority of previous experimental works and evokes that indirect mechanism governs the recombination process. The electron- assisted collisional-radiative recombination of Ar ions was for the first time studied at temperatures 50 - 300 K. The...

A B S T R A C T Title: Recombination of Ions in Plasma at 50 − 300 K Author: Peter Rubovič Supervisor: Prof. RNDr. Juraj Glosík, DrSc. Abstract: Main part of this doctoral thesis lies in a study of recom- bination of atomic and molecular ions in low temperature plasmatic environment with emphasis on effect of third bodies. Stationary After- glow equipped with Cavity Ring Down Spectrometer and Cryogenic Flowing Afterglow with Langmuir Probe II were used to obtain recom- bination rate coefficients. Electron assisted collisional radiative recom- bination of Ar+ ion was studied in the temperature range of 50−100 K and helium assisted collisional radiative recombination was observed too. Both H+ 3 and its isotopologue D+ 3 were studies in flowing after- glow and spectroscopically in stationary afterglow as well. Binary re- combination rate coefficients and ternary recombination rate coeffi- cients for helium assisted ternary recombination were determined in the temperature range of 50 − 250 K. These coefficients were deter- mined also for pure ortho- and para- nuclear spin configurations of H+ 3 in the temperature range of 80 − 200 K. Keywords: dissociative recombination, collisional radiative recombi- nation, H+ 3 , D+ 3 , Ar+ viii

As manifestações vulcânicas e sub-vulcânicas riolíticas do Neoproterozoico do sul do Brasil são correlacionados a um intenso magmatismo ácido, ligados à diferentes associações petrotectônicas do Escudo Sul-Rio-Grandense. Uma porção deste vulcanismo ocorre no Cinturão Dom Feliciano, associado ao Batólito de Pelotas, e é resultante de episódios magmáticos vinculados à ambientes pós-colisionais relacionados com os estágios finais do Neoproterozoico no sul do Brasil. O Riolito Ana Dias é a principal ocorrência sub-vulcânica deste vulcanismo e está situado na região de Quitéria, na parte central do Rio Grande do Sul. O magmatismo ácido tem sido comumente associado com as fases mais diferenciadas das suítes graníticas durante os estágios finais de evolução do Batólito de Pelotas. O Riolito Ana Dias é caracterizado como um corpo intrusivo, constituído por rochas que apresentam textura porfirítica à seriada, variando para termos equigranulares finos. Novas idades U-Pb obtidas em zircões indicam uma idade de cristalização de 581,9 ± 1,9 Ma para estes riolitos. Dados geoquímicos caracterizam as rochas riolíticas como sendo da série alcalina. Apresentam um caráter metaluminoso a peraluminoso com teores elevados de SiO2, álcalis, FeOt/FeOt+MgO e índice agpaítico e baixos conteúdos de Al2O3, CaO e MgO. Os valores de Zr, Rb, Y, Nb e Ga são moderados em comparação com os conteúdos relativamente baixos de Ba e Sr. Estas características geoquímicas de elementos maiores e traços são comuns em magmas ácidos de afinidade alcalina, com caráter dominantemente metaluminoso. O padrão de alguns elementos-traços e ETR é caracterizado por um enriquecimento em elementos mais incompatíveis, o que juntamente com a anomalia negativa em Ba, o leve enriquecimento em Ce em relação aos elementos adjacentes e o enriquecimento de K2O e Rb em relação ao Nb, sugerem magmas derivados de fontes mantélicas, enriquecidas em elementos incompatíveis com alguma forma de participação crustal. As características químicas são semelhantes com as de magmatismo granítico do tipo A, relacionado a ambientes pós-colisionais. Os dados litoquímicos obtidos indicam uma vinculação genética com as rochas graníticas mais diferenciadas da Suíte Dom Feliciano do Batólito Pelotas, associadas ao magmatismo Neoproterozoico pós-colisional do Escudo Sul-Rio-Grandense. / Neoproterozoic volcanic and subvolcanic rhyolitic systems in southernmost Brazil are correlated with acid magmatism linked to different petrotectonic associations of the Sul-Rio-Grandense Shield. A portion of this volcanism in the Dom Feliciano Belt is associated with the Pelotas Batholith, which resulted from magmatic episodes associated with the Ediacaran post-collisional evolution of southern Brazil. Ana Dias Rhyolite is the main subvolcanic occurrence of this volcanism that took place in the Quitéria region, in the central part of Rio Grande do Sul State. The acid magmatism has been commonly associated with the most differentiated granite suite phases during the final stages of emplacement of the Pelotas Batholith. The Ana Dias Rhyolite is characterized as an intrusive body with rocks that present a porphyritic to seriated texture and a gradational variation to fine-grained equigranular rocks. New zircon U-Pb dating indicates crystallization age of 581.9 ± 1.9 Ma for the Ana Dias Rhyolite. Geochemistry data characterize the rhyolites as belonging to the alkaline series; they present a metaluminous to peraluminous character; elevated SiO2 and alkali concentrations, high FeOt/FeOt+MgO ratios and agpaitic index; and low Al2O3, CaO, and MgO contents. The Zr, Rb, Y, Nb, and Ga concentrations are moderate when compared with the relatively low Ba and Sr contents. These geochemistry characteristics are common in acid magmas with alkaline affinity. The behavior of certain trace elements and REE demonstrate enrichment in more incompatible elements, in addition to the negative anomaly of Ba, the slight enrichment in Ce relative to adjacent elements, as well as the enrichment in K2O and Rb relative to Nb, suggesting magmas derived from mantle sources enriched in incompatible elements with some crustal contamination. The chemical characteristics are similar to those of A-type granites associated with Neoproterozoic post-collision magmatism in the Sul-Rio-Grandense Shield.

abstract: The Kuiper Belt Object Haumea is one of the most fascinating objects in the solar system. Spectral reflectance observations reveal a surface of almost pure water ice, yet it has a mass of 4.006 × 1021 kg, measured from orbits of its moons, along with an inferred mean radius of 715 km, and these imply a mean density of around 2600 kg m−3. Thus the surface ice must be a veneer over a rocky core. This model is supported by observations of Haumea's light curve, which shows large photometric variations over an anomalously rapid 3.9154-hour rotational period. Haumea's surface composition is uniform, therefore the light curve must be due to a varying area presented to the observer, implying that Haumea has an oblong, ellipsoidal shape. If Haumea's rotation axis is normal to our line of sight, and Haumea reflects with a lunar-like scattering function, then its axis ratios are p = b/a = 0.80 (in the equatorial cross section) and q = c/a = 0.52 (in the polar cross section). In this work, I assume that Haumea is in hydrostatic equilibrium, and I model it as a two-phase ellipsoid with an ice mantle and a rocky core. I model the core assuming it has a given density in the range between 2700–3300 kg m−3 with axis ratios that are free to vary. The metric which my code uses calculates the angle between the gravity vector and the surface normal, then averages this over both the outer surface and the core-mantle boundary. When this fit angle is minimized, it allows an interpretation of the size and shape of the core, as well as the thickness of the ice mantle. Results of my calculations show that Haumea's most likely core density is 2700–2800 kg m−3, with ice thicknesses anywhere from 12–32 km over the poles and as thin as 4–18 km over the equator. / Dissertation/Thesis / Masters Thesis Astrophysics 2015

As manifestações vulcânicas e sub-vulcânicas riolíticas do Neoproterozoico do sul do Brasil são correlacionados a um intenso magmatismo ácido, ligados à diferentes associações petrotectônicas do Escudo Sul-Rio-Grandense. Uma porção deste vulcanismo ocorre no Cinturão Dom Feliciano, associado ao Batólito de Pelotas, e é resultante de episódios magmáticos vinculados à ambientes pós-colisionais relacionados com os estágios finais do Neoproterozoico no sul do Brasil. O Riolito Ana Dias é a principal ocorrência sub-vulcânica deste vulcanismo e está situado na região de Quitéria, na parte central do Rio Grande do Sul. O magmatismo ácido tem sido comumente associado com as fases mais diferenciadas das suítes graníticas durante os estágios finais de evolução do Batólito de Pelotas. O Riolito Ana Dias é caracterizado como um corpo intrusivo, constituído por rochas que apresentam textura porfirítica à seriada, variando para termos equigranulares finos. Novas idades U-Pb obtidas em zircões indicam uma idade de cristalização de 581,9 ± 1,9 Ma para estes riolitos. Dados geoquímicos caracterizam as rochas riolíticas como sendo da série alcalina. Apresentam um caráter metaluminoso a peraluminoso com teores elevados de SiO2, álcalis, FeOt/FeOt+MgO e índice agpaítico e baixos conteúdos de Al2O3, CaO e MgO. Os valores de Zr, Rb, Y, Nb e Ga são moderados em comparação com os conteúdos relativamente baixos de Ba e Sr. Estas características geoquímicas de elementos maiores e traços são comuns em magmas ácidos de afinidade alcalina, com caráter dominantemente metaluminoso. O padrão de alguns elementos-traços e ETR é caracterizado por um enriquecimento em elementos mais incompatíveis, o que juntamente com a anomalia negativa em Ba, o leve enriquecimento em Ce em relação aos elementos adjacentes e o enriquecimento de K2O e Rb em relação ao Nb, sugerem magmas derivados de fontes mantélicas, enriquecidas em elementos incompatíveis com alguma forma de participação crustal. As características químicas são semelhantes com as de magmatismo granítico do tipo A, relacionado a ambientes pós-colisionais. Os dados litoquímicos obtidos indicam uma vinculação genética com as rochas graníticas mais diferenciadas da Suíte Dom Feliciano do Batólito Pelotas, associadas ao magmatismo Neoproterozoico pós-colisional do Escudo Sul-Rio-Grandense. / Neoproterozoic volcanic and subvolcanic rhyolitic systems in southernmost Brazil are correlated with acid magmatism linked to different petrotectonic associations of the Sul-Rio-Grandense Shield. A portion of this volcanism in the Dom Feliciano Belt is associated with the Pelotas Batholith, which resulted from magmatic episodes associated with the Ediacaran post-collisional evolution of southern Brazil. Ana Dias Rhyolite is the main subvolcanic occurrence of this volcanism that took place in the Quitéria region, in the central part of Rio Grande do Sul State. The acid magmatism has been commonly associated with the most differentiated granite suite phases during the final stages of emplacement of the Pelotas Batholith. The Ana Dias Rhyolite is characterized as an intrusive body with rocks that present a porphyritic to seriated texture and a gradational variation to fine-grained equigranular rocks. New zircon U-Pb dating indicates crystallization age of 581.9 ± 1.9 Ma for the Ana Dias Rhyolite. Geochemistry data characterize the rhyolites as belonging to the alkaline series; they present a metaluminous to peraluminous character; elevated SiO2 and alkali concentrations, high FeOt/FeOt+MgO ratios and agpaitic index; and low Al2O3, CaO, and MgO contents. The Zr, Rb, Y, Nb, and Ga concentrations are moderate when compared with the relatively low Ba and Sr contents. These geochemistry characteristics are common in acid magmas with alkaline affinity. The behavior of certain trace elements and REE demonstrate enrichment in more incompatible elements, in addition to the negative anomaly of Ba, the slight enrichment in Ce relative to adjacent elements, as well as the enrichment in K2O and Rb relative to Nb, suggesting magmas derived from mantle sources enriched in incompatible elements with some crustal contamination. The chemical characteristics are similar to those of A-type granites associated with Neoproterozoic post-collision magmatism in the Sul-Rio-Grandense Shield.

La relaxation thermo-chimique d’écoulements hypersoniques d’azote derrière des chocs forts et pour des détentes en tuyères est étudiée en effectuant des simulations d’écoulements 1D basées sur une cinétique vibrationnelle détaillée. Ces modèles vibrationnels détaillés sont utilisés pour développer des modèles macroscopiques précis et peu coûteux en temps de calcul pour les codes multidimensionels d’écoulements de rentrée. On considère d’abord les couplages hors équilibre entre l’excitation vibrationnelle et les réactions de dissociation / recombinaison. La cinétique vibrationnelle est décrite en utilisant des bases de constantes de réaction vibrationnelles précises de la littérature, complétées par le modèle de l’oscillateur harmoniques forcé. Le rôle prépondérant des processus vibration-translation multiquanta sur la relaxation de la distribution vibrationnelle et les processus de dissociation / recombinaison est mis en évidence derrière les chocs et dans les tuyères. Les distributions vibrationnelles, qui dévient fortement de l’équilibre dans les détentes en tuyères, résultent des processus vibration-translation et de dissociation / recombinaison. Un modèle macroscopique utilisant des groupes de niveaux vibrationnels est développé pour calculer de manière consistante les termes sources de chimie et d’énergie vibrationnelle à partir de la base de constantes de réaction vibrationnelles. Ce modèle reproduit précisément les dynamiques des températures, de la chimie et des distributions vibrationnelles avec un groupe de niveaux derrière un choc et trois groupes de niveaux pour les détentes. Dans un second temps, le modèle détaillé est généralisé aux écoulements d’azote ionisé en adoptant en particulier un modèle détaillé des processus résonants électron-vibration. Derrière les chocs, ces processus contrôlent la dynamique d’ionisation en alimentant les électrons en énergie, jusqu’à ce que les échanges élastiques électron-ion prennent le relais. Il est montré que l’hypothèse couramment utilisée d’équilibre entre les températures des électrons et de vibration conduit à une relaxation trop rapide derrière les chocs. Dans les détentes en tuyère pour lesquelles la concentration en électrons est faible, la température des électrons est contrôlée par les processus électron-vibration. On observe que les électrons sont fortement couplés aux bas niveaux vibrationnels, et que le nombre de niveaux couplés augmente avec la température des électrons. Le couplage de l’écoulement avec le rayonnement, modélisé dans l’approximation des plans tangents, impacte fortement la population du second métastable et de deux états électroniques plus élevés de N. Finalement, le modèle macroscopique est généralisé à l’azote ionisé. Un bon accord avec le modèle détaillé est obtenu avec un groupe de niveaux derrière un choc et trois groupes de niveaux pour les détentes en tuyère. En particulier, le modèle macroscopique proposé décrit plus précisément les échanges électron-vibration que le modèle de Landau-Teller couramment utilisé. / The thermo-chemical relaxation of nitrogen hypersonic flows behind strong shocks and in nozzle expansions is investigated with 1D flow simulations and detailed vibrational kinetics. This work aims at deriving from detailed vibrational models accurate reduced models easy to implement in multidimensional reentry flow codes. First, nonequilibrium couplings between vibrational excitation, dissociation and recombination reactions are considered. Vibrational kinetics is described using accurate vibrational state-to-state rate constant databases of the literature completed with the forced harmonic oscillator model. The key role of multiquanta vibration-translation processes on the relaxation of the vibrational distribution function and the dissociation/recombination processes is put forward behind shocks and in nozzles. The vibrational distributions, which deviate strongly from equilibrium for nozzle expansions, are driven by vibration-translation processes and dissociation/recombination processes. A macroscopic model using groups of vibrational levels is developed to derive consistently the chemical and vibrational energy source terms from the vibrational state-to-state database.This model successfully reproduces the thermal, chemical and vibrational distribution function dynamics predicted by the state-to-state model with one group of levels behind a shock wave, and with three groups of levels in nozzle expansions. In a second step, the detailed vibrational model is extended to ionized nitrogen flows, including in particular a detailed modeling of the resonant electronvibration processes. Behind shocks, these processes control the rate of ionization by feeding energy to the electrons, up until the time when the elastic electron-ion exchanges takes over. It is shown that the widely used assumption of equilibrium between the electron and vibration temperatures predicts a too fast relaxation behind shock waves. In nozzle expansions, it is shown that for low electron concentration, the electron temperature is driven by electronvibration processes. Moreover, it is found that electrons are strongly coupled to low vibrational levels, and that more levels are coupled when the electron temperature increases. Coupling of the flow field with radiation is performed using the tangent slab approximation, and it is shown that the population of a metastable and two higher electronic levels are strongly impacted. Finally, the macroscopic model is extended to ionized nitrogen flows and is successfully applied on shock waves with one group of levels and with three groups of levels in nozzle expansions. In particular, the proposed macroscopic model represents more accurately the electron-vibration coupling than the widely used Landau-Teller model.

As manifestações vulcânicas e sub-vulcânicas riolíticas do Neoproterozoico do sul do Brasil são correlacionados a um intenso magmatismo ácido, ligados à diferentes associações petrotectônicas do Escudo Sul-Rio-Grandense. Uma porção deste vulcanismo ocorre no Cinturão Dom Feliciano, associado ao Batólito de Pelotas, e é resultante de episódios magmáticos vinculados à ambientes pós-colisionais relacionados com os estágios finais do Neoproterozoico no sul do Brasil. O Riolito Ana Dias é a principal ocorrência sub-vulcânica deste vulcanismo e está situado na região de Quitéria, na parte central do Rio Grande do Sul. O magmatismo ácido tem sido comumente associado com as fases mais diferenciadas das suítes graníticas durante os estágios finais de evolução do Batólito de Pelotas. O Riolito Ana Dias é caracterizado como um corpo intrusivo, constituído por rochas que apresentam textura porfirítica à seriada, variando para termos equigranulares finos. Novas idades U-Pb obtidas em zircões indicam uma idade de cristalização de 581,9 ± 1,9 Ma para estes riolitos. Dados geoquímicos caracterizam as rochas riolíticas como sendo da série alcalina. Apresentam um caráter metaluminoso a peraluminoso com teores elevados de SiO2, álcalis, FeOt/FeOt+MgO e índice agpaítico e baixos conteúdos de Al2O3, CaO e MgO. Os valores de Zr, Rb, Y, Nb e Ga são moderados em comparação com os conteúdos relativamente baixos de Ba e Sr. Estas características geoquímicas de elementos maiores e traços são comuns em magmas ácidos de afinidade alcalina, com caráter dominantemente metaluminoso. O padrão de alguns elementos-traços e ETR é caracterizado por um enriquecimento em elementos mais incompatíveis, o que juntamente com a anomalia negativa em Ba, o leve enriquecimento em Ce em relação aos elementos adjacentes e o enriquecimento de K2O e Rb em relação ao Nb, sugerem magmas derivados de fontes mantélicas, enriquecidas em elementos incompatíveis com alguma forma de participação crustal. As características químicas são semelhantes com as de magmatismo granítico do tipo A, relacionado a ambientes pós-colisionais. Os dados litoquímicos obtidos indicam uma vinculação genética com as rochas graníticas mais diferenciadas da Suíte Dom Feliciano do Batólito Pelotas, associadas ao magmatismo Neoproterozoico pós-colisional do Escudo Sul-Rio-Grandense. / Neoproterozoic volcanic and subvolcanic rhyolitic systems in southernmost Brazil are correlated with acid magmatism linked to different petrotectonic associations of the Sul-Rio-Grandense Shield. A portion of this volcanism in the Dom Feliciano Belt is associated with the Pelotas Batholith, which resulted from magmatic episodes associated with the Ediacaran post-collisional evolution of southern Brazil. Ana Dias Rhyolite is the main subvolcanic occurrence of this volcanism that took place in the Quitéria region, in the central part of Rio Grande do Sul State. The acid magmatism has been commonly associated with the most differentiated granite suite phases during the final stages of emplacement of the Pelotas Batholith. The Ana Dias Rhyolite is characterized as an intrusive body with rocks that present a porphyritic to seriated texture and a gradational variation to fine-grained equigranular rocks. New zircon U-Pb dating indicates crystallization age of 581.9 ± 1.9 Ma for the Ana Dias Rhyolite. Geochemistry data characterize the rhyolites as belonging to the alkaline series; they present a metaluminous to peraluminous character; elevated SiO2 and alkali concentrations, high FeOt/FeOt+MgO ratios and agpaitic index; and low Al2O3, CaO, and MgO contents. The Zr, Rb, Y, Nb, and Ga concentrations are moderate when compared with the relatively low Ba and Sr contents. These geochemistry characteristics are common in acid magmas with alkaline affinity. The behavior of certain trace elements and REE demonstrate enrichment in more incompatible elements, in addition to the negative anomaly of Ba, the slight enrichment in Ce relative to adjacent elements, as well as the enrichment in K2O and Rb relative to Nb, suggesting magmas derived from mantle sources enriched in incompatible elements with some crustal contamination. The chemical characteristics are similar to those of A-type granites associated with Neoproterozoic post-collision magmatism in the Sul-Rio-Grandense Shield.

Les théories de champ moyen quantique représentent une base robuste pour la description de la dynamique de nombreux systèmes physiques, des noyaux aux systèmes moléculaires et aux agrégats. Cependant, le traitement incomplet des corrélations électroniques au niveau du champ moyen empêche de donner une description propre de la dynamique, en particulier la dynamique dans les régimes dissipatifs. La dissipation est intrinsèquement liée à la thermalisation qui représente le phénomène cible à d'écrire dans ce travail. Nous avons exploré un schéma purement quantique en terme des matrices densités et qui consiste en l'inclusion des corrélations de type collisions, responsables de la thermalisation dans les systèmes quantiques finis. Ceci est fait en traitant les corrélations entre deux particules avec la théorie des perturbations dépendantes du temps tout au long d'un intervalle de temps. Ceci permet de créer un ensemble d'états de type champ moyen pur pour les différentes configurations. Ces états sont traités stochastiquement dans la dynamique et fournissent en moyenne un état corrélé. Nous proposons dans ce travail une reformulation de cette théorie en terme des fonctions d'ondes où les corrélations sont traitées comme des transitions multiples de type particule-trou, limitées aux transitions deux-particules-deux-trous dans notre cas. On applique le schéma obtenu à un modèle unidimensionnel simulant de petites molécules. La capacité de cette théorie à introduire les effets dissipatifs dans le cadre du champ moyen est illustrée à travers plusieurs observables tels que les matrices à un et deux corps, les nombres d'occupation et l'entropie à un corps / Quantum mean field theories represent a robust basis for the description of many dynamical situations from nuclei to molecular systems and clusters. However, the missing of electronic correlations on top of mean field prevents them to give a proper description of the dynamics, in particular dissipative dynamics. Dissipation is intrinsically linked to thermalization which represents the target phenomenon to be described in this thesis. We thus explore a fully quantum mechanical strategy proposed in terms of density matrices in the case of nuclear collisions and which consists in the inclusion of collisional correlations responsible of thermalization in quantum finite systems. This is done by treating two body correlations in time dependent perturbation theory along a certain time span that allows to create an ensemble of pure mean field states for different configurations. These states are used into the dynamics, stochastically, providing in the average one correlated state. We propose in this work a reformulation of this theory in term of wave functions where correlations are translated into multiple particle-hole transitions, restricted to two-particles-two-holes transitions in our case. We apply the obtained scheme to a one dimensional model simulating small molecules. The ability of this theory to include dissipative effects on top of mean field is illustrated through several observables such as the one and two body density matrices, the occupation numbers and the one body entropy.

This work is devoted to a study of dynamical and collisional processes, governing populations of small bodies in the Solar System. It pays special attention to asteroid families and Jupiter Trojans. Librating around L4 and L5 Lagrangian points of the Sun-Jupiter-asteroid system, these asteroids are believed to be captured from the trans- Neptunian region during a giant planet system instability about 4 Gy ago. We discovered (back in 2011) there is only one significant collisional family among Trojans, associated with C-type asteroid (3548) Eurybates, i.e., one of the targets for the upcoming 'Lucy' mission. Detailed analysis of new proper resonant orbital elements, colours and albedos, together with statistical significance computations, allowed us to find five more collisional families: Hektor, (9799), Arkesilaos, Ennomos, and (247341). The discovery of the first D-type family associated with (624) Hektor was the most surprising, because it is the most primitive taxonomic type. Using long-term dynamical simulations of synthetic families, evolving by chaotic diffusion, we estimated the ages of the Eurybates and Hektor families, approximately (2.5±1.5) Gy for both. We also studied impact processes by means of the smoothed-particle hydrodynamics (SPH). We simulated cratering events on (624) Hektor, the origin...