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Optimisation of experimental parameters for double-pulse LIBS
Roščák, Michal ; Novotný, Karel (referee) ; Kaiser, Jozef (advisor)
Diploma thesis presents the description of laser induced breakdown spectroscopy (LIBS) analytical method. The possibility to decrease LIBS detection limits using double pulse LIBS (DP-LIBS) is also detailed. Properties of laser induced plasma (LIP) are discussed. Thesis describes the optimisation process of DP-LIBS setup at laser spectroscopy laboratory of Faculty of Mechanical Engineering, Brno University of Technology. Optimisation was carried out for detection of chrome in steel with respect to detection limits and ablation crater size. Optimised DP-LIBS setup is appropriate for mapping chrome distribution in steel samples.
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Comparison of quantitative LIBS analysis of steel standards utilizing single-pulse and double-pulse LIBS
Pořízka, Pavel ; Hrdlička, Aleš (referee) ; Kaiser, Jozef (advisor)
In this diploma thesis the differences between single pulse and double pulse laser induced breakdown spectroscopy (LIBS) methods are discussed. The time evolution of laser induced plasma (LIP) parameters, such electron density, plasma temperature, density of ions and atoms is shown. Selected methods for evaluation of plasma parameters (Boltzmann equation, Saha-Boltzmann equation etc.) are also stated. The theoretical bases of local thermodynamic equilibrium (LTE), which is necessary condition for using of previously stated methods for computation of plasma parameters, are discussed. Diploma thesis also contains the description of each component of our LIBS experimental set up and the way of their optimization. Presented theoretical advantages of DP LIBS method are demonstrated on results of experimental measurements of steel standards.
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Optimization of the experimental parameters for laser induced breakdown spectroscopy (LIBS) of selected plant samples
Prochazka, David ; Novotný, Karel (referee) ; Kaiser, Jozef (advisor)
This diploma thesis describes optimization of the experimental parameters for Laser-induced breakdown spectroscopy of plant samples. First part deals with the theoretical method of LIBS and explains the principles and terms. In the next part there is described device which was used for measurements. Main part of diploma thesis describes creation of program for measurement-automation. Main task of program was to solve the connection of autofocus on the sample with the sample automatic movement. Furthermore are described and elaborated specific measurements for optimization of the experimental parameters for Laser-induced breakdown spectroscopy of plant samples.
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Element analysis of magnesium alloys using laser induced breakdown spectrometry
Veis, Samuel ; Fintová, Stanislava (referee) ; Doležal, Pavel (advisor)
Bachelor‘s thesis is aimed at assessing the possibilities of trace elements detection in magnesium alloys using laser induced breakdown spectroscopy with a focus on rare earth elements. Base materials were wrought magnesium alloy sheet ZE10 with thickness of 1,6 mm and ZE41 with thickness of 2 mm produced using Direct Chill casting method. Qualitative and quantitative ways of LIBS spectra evaluation were described in the work. Qualitative analysis confirmed the presence of La, Ce, Nd and Pr in ZE41, and La with Ce in ZE10. These informations confirm results of EDS analysis. For a demonstration, quantitative analysis of ZE10 was made, which confirmed the possibility of using LIBS for detection of REE in Mg alloys.
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Enhancement of detection limits in Laser-Induced Breakdown Spectroscopy (LIBS) using nanoparticles
Képeš, Erik ; Prochazka, David (referee) ; Sládková, Lucia (advisor)
This bachelor's thesis describes the options of ehnancing the detection limits of laser-induced breakdown spectroscopy (LIBS). It summarizes different modifications of the classical LIBS apparatus, which are used by methods double-pulsed LIBS (DPLIBS), Townsend effect plasma sectroscopy (TEPS), resonance enhanced LIBS (RELIBS), spark discharge LIBS (SDLIBS), flame-enhanced LIBS (FELIBS), and new ways of sample preparation, such as are used in the method nanoparticle enhanced LIBS (NELIBS). It briefly describes the mechanisms, which are used by each method to reduce the detection limit and it contains an overview of obtained enhancements against the classical method LIBS. It deals with the method nanoparticle enhanced LIBS in more detail and experimentally verifies and studies the effects of nanoparticles of different types and sizes on the emission spectrum of the method LIBS.
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Modification of Targeting Camera for a Remote Laser Spectroscopy
Klempa, Tomáš ; Ficza, Ildikó (referee) ; Brada, Michal (advisor)
The bachelor thesis deals with the modification of targeting camera for remote laser spectroscopy. Targeting camera will be used on remote laser spectroscopy unit to study its features in laboratory of Institute of Physical Engineering on University of Mechanical Engineering Brno and to study the affect of external environment to analytic ability. The thesis contains a brief overview of the current stage of knowledge, designs of stroctural variations and the description of parts of designed device.
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Modification of the focusing part of the table-top setup for Laser Induced Breakdown Spectroscopy (LIBS)
Borovský, Ján ; Prochazka, David (referee) ; Samek, Ota (advisor)
This bacheolor thesis solves functional modifications of the foccusing part of the table-top setup for laser induced breakdown spectroscopy LIBS. Main requirements for modified draft includes increasing view field of the navigation camera, increasing the setup’s aperture and prevention of the camera destruction by radiation of plasma. These requirements were fulfilled in new draft of optical stand including possible solution as enlarging focusing lens, new dielectric mirror and mechanical iris shutter. Some elements of proposed solution will be used in suggestion of Tescan company‘s new interaction chambers for LIBS analysis.
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