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Diagnostics of low-temperature plasma using the Langmuir and emissive probes
Klusoň, Jan ; Kudrna, Pavel (advisor) ; Tichý, Milan (referee)
Magnetron sputtering belongs to the most important methods of production of thin films with a wide range of physical properties. Examples include hard, wear-resistant coatings, low friction ones, corrosion resistant ones as well as coatings with specific electrical or optical properties. During the development the basic sputtering process has been significantly improved and nowadays there are a number of various techniques of magnetron sputtering. Pulsed magnetron sputtering presents one of these techniques. The pulsed regime is especially suitable for the deposition of insulating layers because there occurs no effect of charging up of the target followed by arc events. The fact that pulsed sputtering allows reducing the substrate temperature during the deposition is also important. This thesis deals with the low-temperature plasma in magnetron discharge generated by pulsed DC voltage. The measurement was carried out in the experimental apparatus of the cylindrical magnetron. The plasma diagnostics was performed by means of the electrostatic Langmuir and emissive probe. The dependencies of the basic plasma parameters, i.e. electron density, electron temperature and plasma potential, were evaluated with time and spatial resolution. The dependencies on pressure, length of the voltage pulse and the value of...
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Selected issues of thermonuclear fusion in tokamak-like magnetic containers
Ondáč, Peter ; Tichý, Milan (advisor) ; Kudrna, Pavel (referee)
In this thesis there are summarized in the form of basic knowledge the basic problems of fusion research. It serves as an introduction to this field of physics for beginners, but also intermediate candidates. The first two chapters set out the basic terms and ideas associated with controlled thermonuclear fusion. Further described is the magnetic confinement in tokamaks. Physically most important is the third chapter, which includes more advanced parts of physics. It discusses the main focus of this work, i.e. some of the major problems hindering fusion research. Final fourth chapter is relaxed. It discusses the ideas and visions for the near and distant future.
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Discharge plasma sources supported by magnetic field
Kolpaková, Anna ; Kudrna, Pavel (advisor) ; Marek, Aleš (referee)
This work concerns the low-temperature plasma diagnostic in the dcdischarge in the cylindrical magnetron in argon. For measurements Langmuir and emissive probes were used. The aim of this diploma work was the diagnostics of the radial plasma parameters especially with the improved construction of the emissive probe and the verification of it's use for the determination of the plasma potential. The work was also focused on the influence of the angle between the emissive probe loop and the magnetic field to the emissive probe data. In the experimental part the cylindrical magnetron system, the construction of Langmuir and emissive probes and the probe circuit are described. After that the software for the data acquisition created using Agilent VEE programming language and evaluation of probe data is explained. Probe characteristics were measured by the Langmuir probe in the dependence on the radial position. In such way the radial profiles of the plasma potential, floating potential and electron density were determined. Measurements were performed at different values of the pressure, magnetic field and the discharge current. The floating potential of the strongly emitting probe was used to measure the plasma potential at different magnetic field strengths.
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Influence of the laser mixture composition on the existence of the dinitrogen bands
Morávek, Matěj Jan ; Hrachová, Věra (advisor) ; Kudrna, Pavel (referee)
This project studies mixtures of helium, nitrogen and carbon dioxid, widely used in so called CO2 lasers. These lasers are classified as discharge lasers. In the case of low output lasers is often used a DC glow discharge. We can find bands so called first and second positive systems of a dinitrogen molecule in an emission spectrum of the glow discharge. It is possible to deduce energetic balance and a vibrational temperature from these bands. The vibrational temperature was studied by the vibrational spectroscopy of dinitrogen molecule for various discharge currents and pressures and for various distribution of nitrogen in the mixture (we will start with an industrial mixture LASAL 63).
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Studies of tokamak edge plasma and its interaction with the first wall
Komm, Michael ; Kudrna, Pavel (advisor) ; Hrach, Rudolf (referee) ; Svoboda, Vojtěch (referee)
Title: Studies of tokamak edge plasma and its interaction with the first wall Author: Michael Komm Department: Department of Surface and Plasma Science Thesis director: doc. Mgr. Pavel Kudrna, Dr. KFPP Thesis supervisor: Dr. Renaud Dejarnac, IPP CAS CR Abstract: This work presents results of simulations of nuclear fusion related problems, using both 2D PIC code (SPICE2) and full 3D code (SPICE3). The simulations allowed us to predict particle and heat loads coming from plasma onto the divertor tiles, which is a key problem for the next-step de- vices. The results of simulations contributed to the research of fuel retention in the gaps between divertor tiles. We we also able to explain the behaviour of the Katsumata probe and verify the validity of its measurements. Keywords: Tokamak, PIC, divertor, tritium, Katsumata
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Pirate parties as liberal parties?
Kudrna, Pavel ; Brunclík, Miloš (advisor) ; Perottino, Michel (referee)
The diploma thesis aims to confirm whether Pirate parties are liberal and left-libertarian parties and that they are similar to green parties in this way. After 2006 Pirate parties emerged gradually as a new alternative to manage the politics and democracy in Western democracies. Pirates came up with themes such as the fight against copyright or the protection of individuals within the internet. In the first theoretical part of this thesis both liberalism and left-libertarianism as well as Green parties are discussed. The second empirical part deals with Pirate parties. First, their origin and development are described and, with an emphasis on Swedish, German, Icelandic and the Czech Pirate Party - because of their relevance associated with electoral successes -, basic elements of their programmes are introduced. Based on those findings the analysis confronting the elements of liberalism and left-libertarianism with programmes of Pirate parties is performed in the final section of the thesis. The hypothesis that Pirate parties are predominantly left-libertarian parties is proved. Powered by TCPDF (www.tcpdf.org)
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Diagnostics of plasmas for technological applications
Turek, Zdeněk ; Kudrna, Pavel (advisor) ; Kousal, Jaroslav (referee)
The subject of the master thesis is the extension of the measurement of plasma para- meters by the Langmuir probe in a system with a planar magnetron and a hollow cathode operating in pulse mode. The main tasks are to modify the measuring circuit to increase the maximum probe current and to put the USB oscilloscope into operation for data collection with higher resolution and higher sampling rate. Furthermore, the function of the entire device will be verified using test circuits and also by measuring the probe characteristics in discharges in a system with a magnetron and a hollow cathode in both continuous and pulse mode. 1
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