|
|
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.
|
|
|
Water management study at the upper part of the Štinkovka stream
Svoboda, Vojtěch ; Vrba, Jan (referee) ; Veselý, Jaroslav (advisor)
The diploma thesis deals with the study of water management in the upper part of the Štinkovka river basin based on water management analysis. In the past, there was water in the area that is currently lost. Therefore, a terrain reconnaissance was carried out in the thesis to identify problematic areas and to collect samples for laboratory analysis, which were used for sediment studies. Since 2017, water level monitoring has been carried out using an ultrasonic sensor. Measures are proposed to increase water retention in the landscape. The possibility of sports and recreational boating on the Přední rybník pond with a connection to a cycle path and increase public interest in the area are evaluated.
|
|
|
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...
|
guest ::
RSS feed.