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Design and implementation of the plasma control system for the COMPASS tokamak
Janky, Filip ; Horáček, Jan (advisor) ; Kudrna, Pavel (referee) ; Svoboda, Vojtěch (referee)
Design and implementation of the plasma control system Mgr. Filip Janky The COMPASS tokamak was recommissioned in 2007 and it needed new digital controllers for its experimental research. This thesis presents the design and imple- mentation of control of main plasma parameters such as plasma current, plasma position, plasma shape and electron density. Improved plasma current control with resetting set points suppresses overshooting and thus increases the length of the flat top phase. A method for estimating the plasma position, gain tuning for the controller and decreasing latencies and delays to obtain robust position control are presented. Lower delays improve plasma stability and decrease the frequency of disruptions. The plasma shape controller is a feedforward controller with a method to suppress oscillations which are coming from mutual inductance between power supplies controlling plasma horizontal position, plasma shape and plasma current, which all use the same coil. Averaged electron density is corrected in real-time according to the interferometer line of sight and a non-linearity of measurement. Controllers and their improvements described here, played a major role in achiev- ing H-mode scenario and fulfilling the experimental program. Keywords: tokamak, plasma current control, plasma position...
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Cleanthes' hymn to Zeus in its archaic Greek context
Svoboda, Vojtěch ; Kratochvíl, Zdeněk (advisor) ; Jirsa, Jakub (referee)
In its general part, this study tracks archaic motives in the Stoic (and at the first place Kleanthes') cosmology, in particular in respect of his conception of tonos. It concerns the relationship between the Stoics and the pre-Socratic philosophers as such, namely their attitude to Heraclitus. The study examines the transition of the text of Heraclitus' book to the Stoa and the role of different interpretations of Heraclitus as to the Stoic reception. In its special part, I concentrate on the place of the Hymn to Zeus in the hymnal tradition, especially on the influence of Aeschylus who carries many archaic elements. The final passage contains, hopefully, a complete list of parallels between the extant fragments of Heraclitus and the Hymn of Cleanthes.
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Protocolar and observation sentences
Navara, David ; Peregrin, Jaroslav (advisor) ; Svoboda, Vladimír (referee)
This work focuses on the comparison of Carnap's account of protocolar sentences and Quine's account of observation sentences. Carnap's works on protocolar sentences date back to the beginning of 1930's. His chief idea was to make a bridge between science and experience and to transmit the connection between the terms of various scientific fields. Some of Carnap's ideas were questioned by Otto Neurath, who shared with Carnap the physicalistic approach, but had a different view on the desirable features of the protocolar sentences. Within Carnap's theory, protocolar sentences were intended to refer to the sensory characteristics of the physical world. The very conception of protocolar sentences was inspired by physicist's or psychologist's reports, but protocolar sentences in Carnapean sense could also be produced by animals or machines. Carnap originally believed some protocolar sentences to be fundamental and unquestionable. They should have afforded a safe ground for the development of science. Neurath's objections against such a view forced Carnap to adjust his own theory. Carnap also gave up his hopes of total verification, but still expected his theory to enable the confirmation of the general statements of the form "Every X is Y." with a sufficient level of certainty. Carnap's conception faced various...
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The truth of future contingent propositions as a logical and philosophical problem
Kolínská, Marie ; Svoboda, Vladimír (advisor) ; Bendová, Kamila (referee)
According to some logicians and philosophers, future contingent propositions pose a specific problem. Many of those who look into this problem now and those who looked into it (even hundreds) years ago, refer to Aristotle. Nevertheless not in agreement. Our aim is to give an overview of traditional and non-traditional interpretations of the part of Aristotle's work which deals with this issue. On the basis of their comparison we will try to uncover what causes the variety of readings. That will allow us to assess whether the truth of future contingent propositions really is a specific problem and what is its actual nature.
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Hare's thesis as a logical and philosophical problem
Luhan, Martin ; Svoboda, Vladimír (advisor) ; Marvan, Tomáš (referee)
Title: Hare's thesis as a logical and philosophical problem Author: Martin Luhan Department: Department of Logic Supervisor: PhDr. Vladimír Svoboda, CSc. Abstract: The present work is aiming to analyse the problem of inferring from impe- rative premisses to an indicative conclusion which goes by the name Hare's Thesis. The logical analysis of the language of morals was the basis of Richard M. Hare's ethical studies. Therefore a brief presentation of his philosophy is given followed by a detailed walkthrough of his way of dealing with impera- tives. Hare states that logic should be interested in dealing with prescriptive sentences. The paper also presents a selection of some of the semantics of logic of imperatives and some of their fundamental problems. Based on this we finally analyse whether the Hare's Thesis which forbids inferring from im- perative premisses to indicative conclusions is acceptable. And we conclude that in most cases it is reasonable to reject it. Keywords: Logic of imperatives, Hare's Thesis, deontic logic, metaethics
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Study of plasma in tokamak-type devices with spectroscopic methods
Naydenkova, Diana ; Stöckel, Jan (advisor) ; Plašil, Radek (referee) ; Svoboda, Vojtěch (referee)
In Tokamak department of Institute of Plasma Physics, radiation of high-temperature plasma is investigated using spectroscopic methods in visible, ultraviolet and infrared regions. The radiation gives information regarding tokamak plasma parameters and their changes, which is necessary for future realization of fusion reactor. In the frame of this doctoral thesis the development of spectroscopic diagnostics for observing of plasma radiation and its temporal evolution in COMPASS tokamak was performed. The absolute calibration of developed systems in order to recalculate measured signal to units of radiation was done. The sources of imprecisions of absolute measurements in tokamak conditions are properly discussed in the first part of the dissertation. Plasma radiation in the range 257-1083 nm was measured and interpreted using NIST database and FLYCHK code. Ion density for the most significant impurities was estimated. IDL code for effective ion charge estimation as a ratio of real and hydrogen plasma Bremsstrahlung radiation near 523 nm was developed. Profiles of electron density and temperature measured by Thomson scattering system were used for hydrogen plasma Bremsstrahlung radiation calculations. The example of applying of spectroscopic data for studying of COMPASS plasma heating using neutral beam...
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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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