National Repository of Grey Literature 23 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
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...
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.
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...
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
Monitoring of the earth-fill dam of the Karolinka waterworks
Svoboda, Vojtěch ; Novotná, Jitka (referee) ; Pařílková, Jana (advisor)
The bachelor‘s thesis is focused on selected parameters monitoring of the earth dam of hydraulic structure Karolinka. The first outflow areas on the Karolinka dam air face were already observed and the seepages were measured after the first filling. As a result, in addition to standard monitoring, monitoring of the dam by electrical impedance spectrometry was started in 2011. During the reconstruction of the dam in 2013 was realized the construction of the sealing wall for minimalized of seepages. The selected data were compared before and after reconstruction of the hydraulic structure Karolinka. The bachelor‘s thesis was realized within the sustainability of the international project E!7614 of EUREKA program.
Plasma Heat Flux to Solid Structures in Tokamaks
Vondráček, Petr ; Horáček, Jan (advisor) ; Gunn, James P. (referee) ; Svoboda, Vojtěch (referee)
Plasma Heat Flux to Solid Structures in Tokamaks Petr Vondráček Energy and particle exhaust is the key issue for future fusion reactors based on magnetic plasma confinement, namely for tokamaks. Good understanding of processes controlling plasma heat fluxes impinging the first wall of tokamaks is of a main concern for fusion research. This doctoral thesis is focused on experimental investigation of plasma heat fluxes in different locations of the COMPASS tokamak. A new infrared thermography system was built for this purpose as a part of this PhD research. There are four main topics studied using the system. First of all, a narrow near-SOL heat flux channel with a very steep radial profile is characterised in HFS limited discharges. It is shown that the near-SOL heat flux decay length is consistent with the drift-based model of the SOL heat transport. Secondly, heat loading of leading edges of misaligned limiters is broadly studied. The optical approximation of the heat flux distribution around a poloidal leading edge is confirmed as a valid approach. Heat loading of a magnetically shadowed side of a toroidal limiter gap is observed experimentally for the first time confirming predictions of particle-in-cell code simulations. Thirdly, localised hot-spots caused by the impact of runaway electrons as well as...
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...
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...
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.

National Repository of Grey Literature : 23 records found   1 - 10nextend  jump to record:
See also: similar author names
1 SVOBODA, Vlastimil
12 SVOBODA, Václav
1 Svoboda, V.
1 Svoboda, Veronika
1 Svoboda, Viktor
18 Svoboda, Vladimír
2 Svoboda, Vladimír,
12 Svoboda, Vojtěch
12 Svoboda, Václav
8 Svoboda, Vít
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