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Evaluation of gas flow in the scintillation detector at different profiles and sizes of holes in the screens that have shaped the network
Truhlář, Michal ; Špinka, Jiří (referee) ; Maxa, Jiří (advisor)
This work deals with the flow of gas in the scintillation detector. Thesis describes the function of an electron microscope, the composition, distribution and development of microscopes from the earliest to modern. The work also includes familiarization with SolidWorks 3D modeling in which is the electron microscope modeled and Cosmos FloWorks in which they are carried out simulations of gas flow. The paper is focused on the flow of gas in various shapes of the screen and various pressures in chamber of specimen. The results of the analysis of both apertures variants are compared with the request to minimize the pressures in the trajectory of the secondary electrons of well as in the chamber of specimen.
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Modeling HF diode in Comsol Multiphysics
Truhlář, Michal ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
This work brings understanding effects in semiconductor diode by rise P-N junction. Attention devote to suggested high frequency semiconductor diode in program Comsol Multiphysics 3.3.Atention is concentrated to optimization model of diode so as volt-ampere characteristic resembles to real characteristics of diodes. Is tried to find a solution to entourage P-N devolution, where this program sensitive on changes geometry’s barriers of these is different types P-N. In work is summary of treatment and advancing by divining and by optimization of high frequency diode. First part describes semiconductor diode like component used in the electrotechnics, which explains rise, descriptions, using and types of used diodes. Second part includes progress of scaling concrete semiconductor high frequency silicon diode. In this work is braining to optimization model of diode to real and research parameters, which influence her descriptions. In last part of my bachelor’s work was created a simple program in Matlab for global optimization. This program by connected with model of diode and check up possibilities of optimizations their parameters
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Modeling HF diode in Comsol Multiphysics
Truhlář, Michal ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
This work brings understanding effects in semiconductor diode by rise P-N junction. Attention devote to suggested high frequency semiconductor diode in program Comsol Multiphysics 3.3.Atention is concentrated to optimization model of diode so as volt-ampere characteristic resembles to real characteristics of diodes. Is tried to find a solution to entourage P-N devolution, where this program sensitive on changes geometry’s barriers of these is different types P-N. In work is summary of treatment and advancing by divining and by optimization of high frequency diode. First part describes semiconductor diode like component used in the electrotechnics, which explains rise, descriptions, using and types of used diodes. Second part includes progress of scaling concrete semiconductor high frequency silicon diode. In this work is braining to optimization model of diode to real and research parameters, which influence her descriptions. In last part of my bachelor’s work was created a simple program in Matlab for global optimization. This program by connected with model of diode and check up possibilities of optimizations their parameters
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Evaluation of gas flow in the scintillation detector at different profiles and sizes of holes in the screens that have shaped the network
Truhlář, Michal ; Špinka, Jiří (referee) ; Maxa, Jiří (advisor)
This work deals with the flow of gas in the scintillation detector. Thesis describes the function of an electron microscope, the composition, distribution and development of microscopes from the earliest to modern. The work also includes familiarization with SolidWorks 3D modeling in which is the electron microscope modeled and Cosmos FloWorks in which they are carried out simulations of gas flow. The paper is focused on the flow of gas in various shapes of the screen and various pressures in chamber of specimen. The results of the analysis of both apertures variants are compared with the request to minimize the pressures in the trajectory of the secondary electrons of well as in the chamber of specimen.
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Determination of mechanical properties from microcompression test
Truhlář, Michal ; Kruml, Tomáš ; Kuběna, Ivo ; Petráčková, Klára ; Náhlík, Luboš
This paper describes a microcompression test of Al - 1.5 wt. % Cu thin film deposited on Si substrate. Microcompression combines the sample preparation with the use of ion focused beam (FIB) with a compression test carried out using nanoindenter. Cylindrical specimens (pillars) were prepared using FIB. The diameter of pillars was about 1.3 μm and their height was about 2 μm (equal to the film thickness). Stress-strain curves of the thin film were obtained. The results depend on crystallographic orientation of pillar. The paper is focused to an attempt to determine as precisely as possible Young modulus of the film using experimental data and finite element modelling.
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Estimation of mechanical properties of thin Al surface layer
Petráčková, Klára ; Kuběna, Ivo ; Truhlář, Michal ; Náhlík, Luboš ; Kruml, Tomáš
The paper describes a new method for testing of thin layers, so-called microcompression test. As an example determination of Al thin film properties deposited on Si substrate is introduced in the paper. Microcompression combines the sample preparation with the use of focused ion beam (FIB) with a compression test carried out using nanoindenter. Cylindrical specimens (pillars) were prepared in Al film using FIB. The typical diameter of pillars was about 1.3 μm and their height was about 2 μm. The results depend on crystallographic orientation of pillar. Stress-strain curves of the thin film were obtained. Experimentally measured data on pillars needs correction to obtain undistorted material properties of Al thin film. A necessary correction using finite element modeling is suggested in the paper. The paper contributes to a better characterization of very thin surface layers and determination of their mechanical properties.
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