Výpočet dynamiky chování microtronu MT 25 a jeho rychlá simulace
Krist, Pavel; Bíla, J.; Chvátil, David
2011 - Czech Článek se zabývá návrhem matematického modelu, který je vyvíjen z důvodu nastavení a testování fuzzy řídicího systému mikrotronu MT 25. Mikrotron MT 25 je cyklický urychlovač elektronů. Tento typ urychlovače je doposud řízen pouze manuálně operátorem. Matematický model je založen na výpočtu pohybu elektronů v urychlovací dutině a ve vakuové komoře urychlovače. Simulace urychlovače je pak provedena v prostředí Matlab – Simulink. This paper presents the design of a mathematical model and its fast simulation developed for the setup of the control system of the MT 25 microtron, which is a cyclic electron accelerator. This type of accelerator has been controlled manually until now. The mathematical model is based on calculations of the electron motion in the accelerating cavity and vacuum chamber. The simulation diagram was created in Matlab – Simulink. Keywords: Microtron; electron accelerator; electron source; LaB6; beam simulation Available at various institutes of the ASCR Výpočet dynamiky chování microtronu MT 25 a jeho rychlá simulace

Článek se zabývá návrhem matematického modelu, který je vyvíjen z důvodu nastavení a testování fuzzy řídicího systému mikrotronu MT 25. Mikrotron MT 25 je cyklický urychlovač elektronů. Tento typ ...

Krist, Pavel; Bíla, J.; Chvátil, David
Ústav jaderné fyziky, 2011

Using constraint programming in anytime path planner
Zerola, Michal
2011 - English Path planning in one of the critical tasks for autonomous robots. We will study the problem of finding the shortest path for a robot collecting waste spread over the area such that thet robot has a limited capacity and hence during the route it must periodically visit depost/collectors to empty the collected waste. Keywords: Logistika; Autonomní roboti Available at various institutes of the ASCR Using constraint programming in anytime path planner

Path planning in one of the critical tasks for autonomous robots. We will study the problem of finding the shortest path for a robot collecting waste spread over the area such that thet robot has a ...

Zerola, Michal
Ústav jaderné fyziky, 2011

K problematice řízení klasického typu mikrotronu a využití fuzzy logiky
Krist, Pavel; Bíla, J.
2011 - Czech Práce se zabývá problematikou řízení klasického typu mikrotronu s Kapitzovým urychlovacím rezonátorem. Zde je využito fuzzy regulátoru. Hlavním problémem, který vede k použití takovéhoto regulátoru, je problematické měření velikosti urychlovacího napětí. Toto napětí musí být nastaveno velmi pečlivě, jinak nedojde ke splnění urychlovacích podmínek. This work deals with control problems of the classical microtron with Kapitza type of the accelerating cavity. Fuzzy controller is used. The main problem, which led to use this type of controller, is a problematical measurement of the radio-frequency electric field inside accelerating cavity. Careful setting of this electric field is necessary for accelerating condition fulfillment. Keywords: Microtron; Electron accelerator; Accelerator controller; Fuzzy logic Available at various institutes of the ASCR K problematice řízení klasického typu mikrotronu a využití fuzzy logiky

Práce se zabývá problematikou řízení klasického typu mikrotronu s Kapitzovým urychlovacím rezonátorem. Zde je využito fuzzy regulátoru. Hlavním problémem, který vede k použití takovéhoto regulátoru, ...

Krist, Pavel; Bíla, J.
Ústav jaderné fyziky, 2011

Charakteristika neutronových toků na mikrotronu MT25
Chvátil, David; Králik, M.; Granja, C.; Krist, Pavel
2011 - Czech Mikrotron je malý cyklický urychlovač elektronů. Jestliže má být využit jako zdroj neutronů, urychlené elektrony musí být konvergovány na neutrony pomocí jaderných reakcí. K měření spekter neutronů produkovaných vysokoenergetickým gama zářením v olověném a uranovém terči byla použita sada Bonnerových koulí vybavených pasivními detektory termálních neutronů. Výtěžek neutronů z uranového terče je přibližně dvakrát vyšší než z terče olověného. Microtron is a small cyclic electron accelerator. When it is used as a source of neutrons, electrons must be converted to neutrons by means of nuclear reactions. Spectra of neutrons produced by high energy X-ray photons in lead and uranium targets installed on the microtron MT25 were measured by the Bonner sphere spectrometer with passive detectors of thermal neutrons. Neutron yield from uranium target was nearly two times higher than from the lead one. Keywords: Microtron; electron accelerator; neutron source; U target; Pb target; Bonner sphere; NAA; Mn foil Available at various institutes of the ASCR Charakteristika neutronových toků na mikrotronu MT25

Mikrotron je malý cyklický urychlovač elektronů. Jestliže má být využit jako zdroj neutronů, urychlené elektrony musí být konvergovány na neutrony pomocí jaderných reakcí. K měření spekter neutronů ...

Chvátil, David; Králik, M.; Granja, C.; Krist, Pavel
Ústav jaderné fyziky, 2011

Proton ICCHIBAN 2 & 3: Results of NPI ASCR participant with various types of thermoluminescent detectors
Ambrožová, Iva; Vlček, Bohumil
2011 - English Keywords: Proton ICCHIBAN 2 & 3; thermoluminescent detectors; NPI ASCR Available at various institutes of the ASCR Proton ICCHIBAN 2 & 3: Results of NPI ASCR participant with various types of thermoluminescent detectors

Ambrožová, Iva; Vlček, Bohumil
Ústav jaderné fyziky, 2011

Emergent Phenomena, Morphomatics and Theory of Complexity
Bíla, J.; Krist, Pavel
2011 - English This paper is devoted to knowledge and symbolical environments for grasping of emergent phenomena. Respecting the fact that the origin of shapes of nature has its essence in emergencies the paper turns attention to formalisms for direct work with such “shapes” (Morphomatics). There are described three environments for grasping of emergent phenomena especially environment 2 as a cognitive tool and environment 3 as dynamic relation between Macrostructure and Microstructure emphasizing their mutual interactions. As an example of formalism developed from synthesis of the introduced three environments is illustrated the use of theory of matroids (dual of Fano matroid) for case of supergravity D=11. Keywords: emergent phenomena; sign model; semantic space; macrostructure; microstructure; matroids Available at various institutes of the ASCR Emergent Phenomena, Morphomatics and Theory of Complexity

This paper is devoted to knowledge and symbolical environments for grasping of emergent phenomena. Respecting the fact that the origin of shapes of nature has its essence in emergencies the paper ...

Bíla, J.; Krist, Pavel
Ústav jaderné fyziky, 2011

Neutron diffraction analysis of residual strain/stress distribution in the vicinity of high strength welds
Mráz, Ľ.; Karlsson, L.; Hamak, I.; Vrána, Miroslav; Mikula, Pavol
2010 - English Residual stresses resulting from non homogeneous heat distribution during welding process belong to most significant factor influencing behavior of welded structures. These stresses are responsible for defect occurrence during welding and they are also responsible for crack initiation and propagation at the either static or dynamic load. The significant effect of weld metal chemical composition as well as the effect of fatigue load and local plastic deformation on residual stress distribution and fatigue life have been recognized for high strength steels welds. The changes in residual stress distribution have then positive effect on cold cracking behavior and also on fatigue properties of the welds [1-3]. Several experimental methods, both destructive and non-destructive, such as hole drilling method, X-ray diffraction, neutron diffraction and others, have been used to examine residual stress distribution in all three significant orientations in the vicinity of the welds. The present contribution summarizes the results of neutron diffraction measurements of residual stress distribution in the vicinity of single-pass high-strength-steel welds having different chemical composition as well as the influence of fatigue load and local plastic deformation. It has been observed that the chemical composition of the weld metal has a significant influence on the stress distribution around the weld. Similarly, by aplying both cyclic load or pre-stress load on the specimens, stress relaxation was observed even in the region of approximately 40 mm far from the weld toe. Keywords: residual stress; neutron diffraction Available at various institutes of the ASCR Neutron diffraction analysis of residual strain/stress distribution in the vicinity of high strength welds

Residual stresses resulting from non homogeneous heat distribution during welding process belong to most significant factor influencing behavior of welded structures. These stresses are responsible ...

Mráz, Ľ.; Karlsson, L.; Hamak, I.; Vrána, Miroslav; Mikula, Pavol
Ústav jaderné fyziky, 2010

Multi-(K)over-bar (hyper)Nuclei and Kaon Condensation
Gazda, Daniel; Mareš, Jiří; Friedman, E.; Gal, A.
2010 - English We report on recent relativistic mean-field calculations of multi-(K) over bar nuclei(1,2) which were performed fully and self-consistently across the periodic table. The (K) over bar separation energy B-(K) over bar as well as the nuclear and (K) over bar -meson densities were found to saturate with the number of antikaons in the nuclear medium. Saturation appears robust against a wide range of variations, including the nuclear model used and the type of boson fields mediating the strong interactions. In addition, we have explored properties of kaonic hypernuclei strange systems made of nucleons, hyperons and K- mesons. We observed saturation also in these objects. Since the (K) over bar separation energy B-(K) over bar does not exceed 200 MeV, multi-(K) over bar nuclei lie energetically well above multi-hyperonic nuclei and it is unlikely that kaon condensation could occur in strong-interaction self-bound hadronic matter. Keywords: Kaonic nuclei; relativistic mean field model; kaon condensation Available at various institutes of the ASCR Multi-(K)over-bar (hyper)Nuclei and Kaon Condensation

We report on recent relativistic mean-field calculations of multi-(K) over bar nuclei(1,2) which were performed fully and self-consistently across the periodic table. The (K) over bar separation ...

Gazda, Daniel; Mareš, Jiří; Friedman, E.; Gal, A.
Ústav jaderné fyziky, 2010

Vyhodnocení úrovně ozáření posádek letadel společnosti ABS JETS, a.s. za rok 2009
Kovář, Ivan; Malušek, Alexandr; Orčíková, Hana; Spurný, František
2010 - Czech Keywords: individual dosimetry; aircrew exposure; radiation transport codes Available at various institutes of the ASCR Vyhodnocení úrovně ozáření posádek letadel společnosti ABS JETS, a.s. za rok 2009

Kovář, Ivan; Malušek, Alexandr; Orčíková, Hana; Spurný, František
Ústav jaderné fyziky, 2010

Residual Stresses Assessment in Coated Materials: Complementarity between Neutron and X-Ray Techniques
Rogante, M.; Mikula, Pavol; Vrána, Miroslav
2010 - English The residual stress (RS) status induced in the substrate of coated materials by the coating process plays frequently a major role in lending the component’s characteristics. RS assessment can give, thus, a substantial contribution in justifying different cases of failure or else bad performance of coated components due to e.g. the coating delamination or to other occurrences which are not simply interpretable via the conventional mechanical tests or microstructure analyses. The adoption of both neutron diffraction (ND) and X-ray diffraction (XRD) techniques has revealed its usefulness in assessing the RS values in proximity of the coating interface area, respectively, without any layer removal or hole drilling at the extreme surface. Keywords: Polysrystalline materials; Residual stress; Neutron diffraction Available at various institutes of the ASCR Residual Stresses Assessment in Coated Materials: Complementarity between Neutron and X-Ray Techniques

The residual stress (RS) status induced in the substrate of coated materials by the coating process plays frequently a major role in lending the component’s characteristics. RS assessment can give, ...

Rogante, M.; Mikula, Pavol; Vrána, Miroslav
Ústav jaderné fyziky, 2010