Intrinsically safe (IS) active power supplies subjected to certain transient load conditions can deliver power to a circuit at significantly higher levels than indicated on their nameplate ratings. During a transient load such as an intermittent short-circuit, energy is transferred from the power supply to the short-circuit and an electrical arc may form when the short-circuit is applied or removed. This poses a spark ignition risk as energy is transferred from the arc to the surrounding atmosphere. Currently various International and Australian Standards define the performance requirements for IS electrical apparatus. A duly accredited laboratory is required to establish the intrinsic safety compliance of an apparatus with the Standards. It involves an assessment of the apparatus and may include testing. The assessment of the apparatus determines adequate segregation, separation, construction, and selection of components. The tests performed on the apparatus include a temperature rise test and in some cases, the sparking potential of the circuit is tested using the spark test apparatus (STA). Testing the sparking potential of active power supplies to establish compliance adds significantly to the time and costs involved in establishing compliance. A new alternative assessment method is proposed in this report to augment or replace the testing phase of the compliance certification process for active power supplies. The proposed alternative assessment method (PAAM) is derived from a determination of the steady-state and transient output characteristics of the active power supply under consideration. Parameters such as peak output current, time constant of peak current decay, and the output voltages at these times are measured from the circuit's output characteristics. These measurements can subsequently be used to derive the topology and component values of an equivalent circuit. The resulting equivalent circuit is then considered like a linear power supply and the sparking potential can be determined using existing assessment methods. This thesis investigates in detail the equivalent circuit of a number of direct current (DC) active power supplies whose transient output characteristics exhibit predominantly capacitive behaviour. The results of the PAAM using the equivalent circuit are then compared with results achieved using the current testing procedure with a STA. A small sample of active power supplies is used to generate data from which a relationship between the current testing procedure and the PAAM can be established. The PAAM developed in this research project can be used as a pre-compliance check by designers, manufacturers, or IS testing stations. A failure of this test would indicate that the active power supply's sparking energy is not low enough to be regarded as intrinsically safe. The PAAM requires fewer resources to establish a result than the STA. The benefits of a simplified spark ignition test would flow on from designers and manufacturers to end users.

The main goal of this thesis is to design intrinsically safe line analyzer. Thesis describes a device that consists of three measuring circuits and a communication circuit. The device is required to measure posistor resistance, isolation state of power cable and line continuity in potentially explosive areas. Document describes basic requirements of ATEX directive matching standards that are related to device. The function of each logical part of the device is described with help of block diagram. After the basic function description an electrical schematic design and component selection is discussed. After this a printed circuit board design follows. Another part of the thesis describes testing software development. At the end of the document the device is assembler and its basic function is verified.

Les effets cohérents dans l’interaction des particules à haute énergie avec les cristauxouvrent de nouvelles opportunités d’accélération et détection de particules. Les champs électromagnétiquesefficaces présents dans les cristaux qui se présentent dans ce cas peuvent dépassermille fois les champs qui sont maintenant réalisables dans les installations expérimentales.La première partie de la thèse est consacrée à l’étude théorique des effets de diffusion multiples surla dynamique et le rayonnement des particules chargées de haute énergie dans les cristaux. L’undes objectifs de cette étude est de trouver des conditions optimales pour effectuer la mesure dumoment magnétique anormal du baryon Lamda au LHC. En raison de la courte durée de vie de cetteparticule, le seul moyen de fournir une telle mesure est d’utiliser un cristal courbé, qui peut imiter lechamp magnétique de l’ordre de milliers de Tesla.L’optimisation des paramètres du set up expérimental a été réalisée sur la base de la simulation parordinateur du passage du Baryon Lamda à travers un cristal courbé à l’aide du modèle de collisions binaires, entenant compte de la diffusion incohérente sur les vibrations thermiques des atomes des noeuds enréseau et de la diffusion sur un sous-système électronique d’un cristal. Les résultats de la recherchemenée dans la thèse démontre la possibilité d’effectuer une telle expérience au LHC et sont devenusla base de la proposition correspondante.Les effets de diffusion multiple des électrons ultra relativistes et le rayonnement des positons dansles cristaux alignés sont également considérés dans la première partie de la thèse.Il est également démontré que la distribution angulaire spectrale et les caractéristiques de polarisationdu rayonnement diffèrent essentiellement des résultats de la théorie de Bethe–Heitler. Lesconditions d’observation expérimentale de ces effets sont présentées.La deuxième partie de la thèse est consacrée à l’étude des processus transitoires des réacteursrapides fonctionnant dans un régime d’onde de combustion nucléaire auto-entretenue (OCN). C’estun nouveau concept de réacteurs de fission nucléaire avec la soi-disant “sécurité intrinsèque”, danslaquelle le développement d’une réaction nucléaire à chaîne incontrôlable est impossible en raisondes principes physiques du fonctionnement du réacteur. Les concepts prometteurs du réacteur OCNdans le cas de sa mise en œuvre permettent d’utiliser l’uranium appauvri et fournit le traitement desdéchets radioactifs à longue durée de vie.Cette étude est basée sur la résolution numérique de l’équation de diffusion non linéaire non stationnairedu transport de neutrons avec un ensemble d’équations de combustion pour les composantsdu carburant et les équations de la cinétique nucléaire pour les noyaux précurseurs des neutronsretardés, en utilisant une approche “effective multigroup”. Le modèle du réacteur cylindrique homogèneavec le combustible métallique des cycles de carburant U–Pu, Th–U et mixte Th–U–Pu estconsidéré dans le cadre du concept de flambage.À la suite de ces études, l’existence du mode OCN dans le cas du combustible mixte Th–U–Puet de ses avantages essentiels est démontrée; l’analyse détaillée d’un type spécial de rétroactionnégative inhérente au régime OCN et sous-jacente à la “sécurité intrinsèque” d’un tel réacteur esteffectuée; les scénarios d’un démarrage en douceur, d’un arrêt forcé et d’un redémarrage ultérieurdu réacteur OCN sont développés. / The coherent effects in the high energy particle interaction with crystals open up new opportunities for accelerating and detecting techniques. The effective electromagnetic fields that arise in this case can exceed a thousand times the fields that are now attainable at experimental installations. The first part of the thesis is devoted to the theoretical study of the multiple scattering effects on the dynamics and radiation of high energy charged particles in crystals. One of the goals of this study is to find optimal conditions to carry out the measurement of the anomalous magnetic moment of the charmed Lambda Baryon at the LHC. Due to the short lifetime of this particle the only way to provide such a measurement is to use a bent crystal, which can imitate the magnetic field of order of thousand Tesla. The optimization of the parameters for an experimental setup was carried out on the basis of computer simulation of the Lamda Baryon passage through a bent crystal using the binary collisions model, taking in to account incoherent scattering on thermal vibrations of atoms at lattice nodes, and scattering on an electronic subsystem of a crystal. The results of the research conducted in the thesis give an optimistic forecast for the possibility of carrying out such an experiment at the LHC and became the basis of the corresponding proposal. The multiple scattering effects of the thesis. This study is performed in the framework of classical electrodynamics approach for describing the relativistic particle radiation and the computer simulation of fast charged particles passing through a crystal using the above-mentioned model. It is shown, that the spectral-angular distribution and the polarization characteristics of radiation essentially differ from the results of the Bethe–Heitler theory. The conditions for the experimental observation of these effects are presented. The second part of the thesis is devoted to the study of transient processes in advanced fast reactor breeder working in a self-sustained nuclear burning wave (NBW) regime. It is a new concept of nuclear fission reactors with the so-called “intrinsic safety”, in which the development of uncontrolled chain nuclear reaction is impossible due to the physical principles of reactor operation. The promising concepts of NBW reactor in the case of its implementation allows to utilize the depleted Uranium and provides the treatment of long-lived radioactive waste. This study is based on numerical solving the non-stationary non-linear diffusion equation of neutron transport together with a set of the burn-up equations for fuel components and the equations of nuclear kinetics for precursor nuclei of delayed neutrons using effective multi-group approach. The model of cylindrical homogeneous reactor with metallic fuel of U–Pu, Th–U and mixed Th–U–Pufuel cycles is considered in the framework of the buckling concept. As a result of these studies the existence of the NBW mode in the case of mixed Th–U–Pu fuel and its essential advantages are demonstrated; the detailed analysis of a special kind of the negative reactivity feedback that is inherent to the NBW regime and underlies the “intrinsic safety” of such a reactor is performed; the scenarios of a smooth start-up, forced shutdown and subsequent restart of the NBW reactor are developed.