La compréhension des processus électroniques engendrés au cours des collisions atomiques ou moléculaires est essentielle au niveau fondamental mais aussi en raison des besoins d’informations quantitatives sur ces processus de plusieurs domaines d’application, notamment la physique médicale et la physique des plasmas. Notre objectif est de fournir une meilleure description de ces processus. Dans le cadre de la thèse, nous avons modélisé les processus électroniques ayant lieu au cours des collisions entre des ions nus et l’atome d’hélium, Aq+-He (2≤q≤10). Cette étude est effectuée dans la gamme des énergies intermédiaires (0.25-625 keV/u) en adoptant le modèle semi-classique non perturbatif de close coupling. Un intérêt particulier est porté sur l’étude des processus de simple et de double capture vu leur grande importance dans cette gamme des vitesses. Plus précisément, nous avons analysé la double capture en détail, en séparant celle peuplant les états liés à celle qui concerne les états auto-ionisants. Cette dernière est particulièrement complexe à modéliser car elle nécessite une bonne description des états doublement excités (au-delà des deux premiers seuils d’ionisation dans notre cas), difficile à implémenter dans une approche dépendante du temps non perturbative comme la nôtre. En analysant les sections efficaces de ces deux processus pour l’ensemble des systèmes étudiés, et en les comparant systématiquement aux données expérimentales et théoriques existantes, nous avons pu extraire un comportement général reliant les processus électroniques les plus favorables à la charge et à la vitesse du projectile considérée. / The understanding of the electronic processes occurring during atomic and molecular collisions concerns the fundamental level but also the needs for quantitative information on these processes, requested by several fields of application, in particular medical physics and plasma physics. Our goal is to provide a better description of these processes. In the framework of the thesis, we have modelled the electronic processes taking place during the collisions between bare ions and the helium atom, Aq +-He (2≤q≤10). This study is carried out in the range of intermediate energies (0.25-625 keV/u), adopting the semi-classical non-perturbative close coupling approach. A particular interest is paid to the single and double capture processes because of their great importance in this energy range. More precisely, we have analysed the double capture processes, splitting the contributions of double capture to bound states and to auto-ionizing states. This latter is particularly complex to describe since it requires a good description of doubly-excited states (beyond the two first thresholds in our study), difficult to implement in time-dependent coupled-channel approaches as ours. By analysing the cross sections of these two processes for all the systems studied and comparing them to available experimental and theoretical data, we were able to extract a general behaviour linking the most favourable electronic processes to the projectile charge and velocity.

This thesis work is to do with the Information system of data boxes (ISDS) which is introduced from legislation's and user's point of view. Because the introduction of this system has influenced hundreds of thousands of subjects the main target of this thesis is to find out about the impact of the ISDS on users with the help of the analysis method. In this work firstly the data provided by the Ministry of Internal Affairs are examined and interpreted, secondly the results of the poll conducted by the author and then a cost-benefit analysis of the system from the users' point of view is carried out. The results of the work show that the ISDS was at the end of the examined period (2009 -- 2013) beneficial for its users and the total economic benefit for the respective period is 3.6 billion Czech crowns. This means that every crown spent on the operation of the system by the Ministry of Internal Affairs represents savings of 2 Czech crowns. The author of this work has come to the conclusion that the system is from a legislative, technological and economic point of view very well created. The author recommends to the system administrator its further development and also recommends to use its potential among thousands of OSVČ (the self-employed).