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Modification of nanomanipulator used in electron microscope
Habarka, Ondrej ; Tkoč,, David (referee) ; Krejsa, Jiří (advisor)
Cílem této diplomové práce je zlepšit chování nanomanipulátoru, používaného v elektronovém mikroskopu, při vykonávaní nejmenších kroků pohybu. První částí je analýza mechanismu za účelem nalezení možných řešení problému. Dále se práce zabývá testováním řešení jako je optimalizace tuhosti předepínacích pružin mechanismu anebo změna mazání šnekového převodu mechanismu. Výsledkem práce je výběr nejvhodnějšího řešení problému na základě výsledků testů a následná modifikace nanomanipulátoru.
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Microscopic analysis of silicon solar cells defects
Brukner, Jakub ; Solčanský, Marek (referee) ; Stojan, Radek (advisor)
This thesis deals with detection of defects solar cells using method electroluminescent, electron microscope and subsequent 3D modeling of areas with defects and structure of the solar cell. In the text are describe basic methods for detection of defects appearing in solar cells. Also some basic defects which can be made during manufacture are there describe. For better orientation the basic principle of functionality and manufacturing process is included.
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Effect of vibration on image quality of the electron microscope
Šafář, Pavel ; Horák, Karel (referee) ; Havránek, Zdeněk (advisor)
My thesis focuses on one the parasitic factors influencing an electron microscope during recording - i.e. the vibrations. Their impact on the quality of the shots is crucial and it is thus desirable to discover the origin of the vibrations and the way they are transmitted on the device and also to strive to eliminate this phenomen as much as possible. Measurements to estimate the source of vibration on the device as well as in its surrounding are a part of my work.
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Measurement and analysis of the detector preamplifier
Temel, Aleš ; republic, David Novák - FEI Czech (referee) ; Klusáček, Stanislav (advisor)
This paper investigates noise characteristics of detector preamplifier in electron scanning microscopes. Various preamplifiers are measured and the lowest noise level amplifier with good level of speed is used. Further measurement of individual levels of amplifier is done and proposed the most suitable way how to achieve the total amplification. By detailed measuring of amplifier structure are found all unpleasant factors that affect the image quality. On the basis of these dates amplifier hardware is adjusted, software solutions to improve image quality designed and model control implemented, which directly controls active elements of preamplifier so that noise for given amplification was the lowest and reached required amplification.
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Analysis of the supersonic flow of gas in the differentially pumped chamber EREM
Matloch, Roman ; Vyroubal, Petr (referee) ; Maxa, Jiří (advisor)
This work describes briefly electron microscopy issue and physical model of fluid flow. Then presented diploma thesis will be describing analysis and evaluation of the impact of supersonic flow on the pressure and density in the path of the primary electron beam in the differential pumping chamber. For analysis, evaluation and examination of the issue will be used CAD and CAE (Computer Aided Engineering) programs. At the same time it will be developed a methodology of calculation applicable to supersonic flow in the low pressure system at ANSYS CFX.
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Image analysis for correction of electron microscopes
Smital, Petr ; Schwarz, Daniel (referee) ; Kolář, Radim (advisor)
This thesis describes the physical nature of corrections of an electron microscope and mathematical methods of image processing required for their complete automation. The corrections include different types of focusing, astigmatism correction, electron beam centring, and image stabilisation. The mathematical methods described in this thesis include various methods of measuring focus and astigmatism, with and without using the Fourier transform, edge detection, histogram operations, and image registration, i.e. detection of spatial transformations in images. This thesis includes detailed descriptions of the mathematical methods, their evaluation using an “offline” application, descriptions of the algorithms of their implementation into an actual electron microscope and results of their testing on the actual electron microscope, in the form of a video footage grabbed from its control computer’s screen.
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