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Analysis of the dimensions of pumping channels in a new design of a scintillation detector
Kryll, Josef ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The aim of this thesis is to study the issue of eniveromental scanning electron microscopy and pumping gas to create a vacuum in the newly designed scintillation detector. Further, creating a model of recently proposed scintillation detector and simulating and analyzing pumping gas in differentially pumped chamber of detector and the results compare with the previous model. The theoretical part deals with electron microscopy, electron sources, electron optics and secondary electrons detectors. It is also presented which signals are generated by the electron beam on the surface of a solid. Further fluid flow issues and equations describing the flow in the solved chamber are dismantled. Furthermore, the impact of gaseous environment on the trajectory of primary electrons, because there are collisions of primary beam with atoms and molecules of gas. The following section discusses creating, quality and importance of the network in mathematical modelling. A method of a final volume used to calculate the differential equations describing the flow of gas at the premises of the microscope is described . The practical part consists in creating a model of scintillation detector and analyzing the gas flow in drawing a vacuum in the newly designed scintillation detector. Furthermore, the simulation results are compared with the results of simulations on the older type of scintillation detector. The output of this thesis is model of recently proposed scintillation detector with visualized simulation results.
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Analyses Of Static Pressure In Oblique Shockwave On The Probe Tip
Jenáček, Jakub
This article deals with the debugging analyses of Ansys Fluent for supersonic flowanalyzes. It is about analyzes on which the debugging of Ansys Fluent was made for analyzes ofsupersonic flow circumfluent the tip of the probe compared with the theory of isoentropic onedimensionalflow as a basic step for further analyzes in low pressures. The results shown in this paperwill further serve as a basis for experimental measuring of given problem.
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Specifics Of Static Pressure Measurement By Pitots Tube
Maxová, Anna
This paper deals with the analysis of the cone of the Pitot tube for sensing the static pressure in the supersonic flow in the experimental chamber. The probe requires a precise tip angle to eliminate a perpendicular shock wave. In our case, the angle tip was evaluated based on the results obtained by mathematical - physical analysis in the Ansys Fluent system. The results presented in this article will further serve as a basis for experimental problem measurement.
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Evaluation Of Continuity Of Environment Based On Knudsen Number Calculations
Jenáček, Jakub
This article deals with the evaluation of the Knudsen number in the research area of the Experimental Chamber. The number indicates the continuity of the environment. In our case, the Knudsen number was evaluated on the basis of results obtained by mathematical - physics analysis in the Ansys Fluent system. The results presented in this article will further serve as a basis for experimental measurement of the problem.
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Influence of experimental chamber pumping on gas temperature
Balobanov, Damir ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The master‘s thesis is focused on issue of pumping in the experimental pumped chambre of an environmental scanning microcope. In the theoretical part, there are presented microscopy as science. Afterwards the thesis is focused on electron microscopy and its problem and vakuum system, computer program used for preparation of simulation and study that the experimental part is based on. The experimental part contains the results of gas flow in the differential pumped chambre. The problematics were solved by Ansys Fluent system.
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Pumping analysis in the experimental chamber for electron microscope using ANSYS system
Dostalová, Petra ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The thesis is focused on issue of pumping in the differential pumped chambre of an environmental scanning microcope. In the theoretical part, there are presented microscopy as science. Afterwards the thesis is focused on environmental scanning electron microscopy and its problem and vakuum system, computer program used for preparation of simulation and study that the experimental part is based on. The experimental part contains the results of gas flow in the differential pumped chambre. The problematics were solved by Ansys Fluent system.
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Analysis of the impact of the baffle placement in the supersonic flow in the differentially pumped chamber
Vlasáková, Martina ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
This thesis deals with the area of the differential pumping chamber of an environmental scanning electron microscope, engaging the pressure limiting apertures and the influence of the enclosure inside the chamber. In the theoretical part, it is first called Microscopy as science, information about microscopes (division of microscopes) and electrons. Afterwards, the theory deals directly with environmental scanning electron microscopy and its problems and vacuum system, mathematical models and computational areas, basic information about the comparative study from, which the thesis is based. In the experimental part there are presented the objectives of the work and the chapter dealing with the processing of results, which are compared with the initial study using the program Ansys Fluent.
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FLOW ANALYSIS OF THE PRESSURE IN THE EXPERIMENTAL CHAMBER OF THE DIFFERENTIAL PUMPING
Šabacká, Pavla ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The thesis deals with the effect of the critical flow, which is produced at pumping of the differential pumping chamber of the Environmental Scanning Electron Microscope (ESEM). The thesis compares the state of the flow in the area of pumped chamber at pressure ratio on the apertures when the critical flow occurs and its advantages in design of the chambers versus the flow without the clogging the nozzle. Problematics were solved using finite volume method by Ansys Fluent system.
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Analysis of the impact of the conic aperture placement in the supersonic flow in the differentially pumped chamber
Rous, Miroslav ; Bílek, Michal (referee) ; Maxa, Jiří (advisor)
The thesis is focused on the medium dynamics simulation in the environmental scanning electron microscope. Specifically, it researches (examines) the conical aperture location effect in the differential pumped chamber and the width of the pumping channel in this chamber. The theoretical part deals with the environmental scanning microscope generally and other tools used in this thesis, e.g. ANSYS Fluen software, fluid turbulence, medium free path of molecules and electrons scattering. In the practical part, the work is focused on data processing from the ANSYS Fluent program and on their evaluation.
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