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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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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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Testing of service life of the bolt fastening used in electron microscopy
Habarka, Ondrej ; Radoš, Jiří (referee) ; Krejsa, Jiří (advisor)
Cílem této bakalářské práce je vybrat vhodný materiál a jeho povrchovou úpravu pro šroubový spoj s jemným závitem na držáku vzorku v elektronovém mikroskopu. První částí je přehled použitelných materiálů a povrchových úprav, které jsou nemagnetické, tudíž neovlivňují elektronový paprsek v mikroskopu. Dále se práce zabývá tvorbou testovacího zařízení na testování životnosti jednotlivých vzorků závitových tyčí. Výsledkem práce je porovnání testovaných materiálů a výběr jednoho nejvhodnějšího pro reálné použití.
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An influence of electron beam on thin oxide films
Kostyal, Michal ; Průša, Stanislav (referee) ; Čechal, Jan (advisor)
This bachelor work deals with a study of the influence of electron beam of scanning electron microscope on the surface of the SiO2/Si (100) – sample. In the work the electron and atomic force microscopy briefly described. The main objective of experimental part is to describe variation in the brightness of sample SiO2/Si (100) in Scanning electron microscope images. In this study is found that on the sample surface are created objects few nm high. The rest of the work is then devoted to measuring the dependence of the object’s high on different variables. Experiments are generally based on the selective irradiation of the sample surface by scanning electron microscope, measurement of irradiated parts using atomic force microscope and evaluation in the application Gwyddion.
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Communication and control card for electron microscope
Robotka, Jan ; Petyovský, Petr (referee) ; Macho, Tomáš (advisor)
The main aim of this thesis is to design a communication and control card for an electron microscope, eventually for other equipments of the company Delong Instruments a.s., which is dealing with its development and production. This card should replace existing communication card because of its low computational performance. Also, it should replace control and measure card manned with A/D and D/A converters. Thus, the new card will be providing not only the communication with a superior PC and other electronic systems, but also the control of other subsystems of the electron microscope, the determining of processional states and the measuring of internal physical quantities. At the beginning the requirements were determined and the main concept was made with the inclusion of the simple block diagram. It was very important to choose a suitable microcontroller, which will be an intelligence of the whole card and so it will be the most important component. The accent was set mainly on the sufficient computational performance, high modularity of its periphery, good vision of the future innovation and support and, of course, the price. The next requirement was the implementation of the Ethernet, which will be used for the communication between the card and the superior PC. The microcontroller which was chosen have the core architecture ARM Cortex-M3 and it is described in separate chapter. The next part of this thesis is dealing with the main communication standard of the card, which is the Ethernet. After the general description, the Ethernet was mainly discussed in context of the chosen microcontroller. The possibilities of the application of higher layer TCP/IP protocols were also discussed. Implied part of the thesis was the selection of other important components, especially A/D and D/A converters. Its characteristics will have a big effect on the characteristics of the card. In the last and the most important phase the electrical scheme was designed and it was described in detail. This scheme is the main result of this thesis and it is the main document for the future realization. Designed card will be able to process and control 16 differential analogue input signals, 16 differential analogue output signals, 8 digital inputs, 8 simple digital outputs and 4 digital outputs triggered by optocouplers. It will be able to communicate with the superior PC over the Ethernet with the maximum bit rate of 100 Mbit/s, with other electronic cards over the serial line UART through the optical fibers and with other internal and external equipments over the RS-485 and RS-232.
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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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