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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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Sport as a Theological Challenge
SVOBODA, Vojtěch
The aim of the thesis is to describe relationships between spirituality, Christianity and sport in history and present. In the first part the author underlines ritual origins of games and sports in pre-Christian cultures, especially ancient Greece and Rome. Revolutionary Christianity separated physical competition from religious ritual. In Christian author´s (Paul, Tertullian, Basil, John Chrysostom, John Cassian and John Climacus) games rating there is an obvious ambiguity They criticized an idolatric origin and connection with cults. Attributes typical for ancient athlete, self-discipline and perseverance, they remained positive. Athletes will and willingness to overcome obstacles gave some of the Fathers of the Church as an example for spiritual struggle, the term "athlete of Christ" had a strong significance in this context. The historical part contains Thomas´s Aquinas valuation of sport in the form of games. In discussion focused on the assessment of the sinful nature of games Aquinas submitted to the rule of reason. One of the key issues in contemporary theology of sport is introduced on the difference between the theological concepts of contemporary authors Rev Dr Lincoln Harvey and Rev Dr Robert Ellis. Harvey's theory, based on a systematic basis, based on the classical axioms of Christian doctrine. Sport is construed as a "liturgy of our contingency", set in the autonomous space that God lovingly gives his creatures. The consequence of this theory is the denial of the transcendent dimension of sport. Ellis´s theory is based on empirical research conducted among athletes. His attention is focused on efforts to achieve the best possible performance by referring to Irenaeus of Lyon, Maslow and others interpreted as a reflection of God's self-transcendence necessary for the creation of man. Sport according to Ellis in contemporary society fullfil some of the functions previously belonging to organized forms of religion. The final section deals with altered states of consciousness in sports and their relationship to the mystique. The author begins by describing his own experiences that are then interpreted from five points of view (philosophical, theological, phenomenological, transpersonal and skeptical). On this basis, the author formulates his own interpretation of the connection between sport and mysticism, whose findings help to deepen the above discussion and also can help with looking for a solution.
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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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Cleanthes' hymn to Zeus in its archaic Greek context
Svoboda, Vojtěch ; Jirsa, Jakub (referee) ; Kratochvíl, Zdeněk (advisor)
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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Anomalous Ion Diffusion in Models of Turbulent Edge Tokamak Plasma
Papřok, Richard ; Krlín, Ladislav (advisor) ; Svoboda, Vojtěch (referee) ; Langer, Jiří (referee)
Enhanced particle and energy transport from edge plasma is observed and may cause a problem for a future operation of a thermonuclear reactor. Plasma edge turbulence presents a complex problem which is not fully theoretically understood. We chose a simple, mathematically simply described potential, which represents first approximation of the realistic one. Resulting dynamics led, for certain class of parameters, to a phenomenon known as Lévy walks, which is the cause of an anomalous enhanced diffusion. It is shown that for typical tokamak's parameters it is in this class and therefore it can be a cause of an anomalous transport in plasma.
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Characteristics of rainfall in observed data and regional climate model simulations
Svoboda, Vojtěch ; Pech, Pavel (advisor) ; Josef, Josef (referee)
Precipitation in the form of heavy rainfall events is of significant societal concern, not only due to the potential for more frequent flash floods, after evidence of changes in rainfall characteristics has recently strengthened. Despite the importance of individual rainfall events with respect to many hydrological applications, only a few studies dealt with characteristics of individual rainfall events (in contrast with the other daily/sub-daily indices of rainfall depths/intensities). Dissertation thesis presents a comprehensive analysis of heavy rainfall event characteristics for the Czech Republic derived from observed data and large ensemble of regional climate model (RCM) simulations. In addition, spatial correlation structure of observed rainfall data at a mesoscale region of north-eastern Bohemia was analysed. Since an RCM grid box represents a spatial average rather than a point measurement, the effects from areal averaging of rainfall data on characteristics of events were investigated considering the observed data. Characteristics of rainfall events were evaluated according to several indices against the at-site and area-averaged observed data for the control period 1981-2000. The changes of rainfall event characteristics were assesed over two scenario periods (2020-2049 and 2070-2099) with respect to control period. We analysed also relations between changes in simulated rainfall event characteristics and changes in radiative forcing and temperature.
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Jean - Luis Barrault
Svoboda, Vojtěch ; PETIŠKOVÁ, Ladislava (advisor) ; HYVNAR, Jan (referee)
This work discusses the life and work of Jean-Louis Barrault, one of the most significant french theatre artist. Barrault is known as an excellent actor, mime, directer and theatre theorist. His contribution to the development of Europian theatre in the last century is very important, especially to mimic theatre styles. The thesis shows Barraults personality and art with a focus on his contribution to pantomime. Another task is to explore influence of different personalities on the artistic development of Jean-Louis Barrault.
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