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Production of cold ions
Tran, Thuy Dung ; Plašil, Radek (advisor) ; Roučka, Štěpán (referee)
1 Abstract: For understanding of the evolution of chemical composition in cold interstellar gas clouds, it is necessary to study the ion-molecule reactions at temperatures from 10 K to 300 K at low pressures. The Ion Trap equipment, which is available in the laboratory of the Department of Surface and Plasma Science, allows this type of experiment. The main element of the Ion Trap is a 22-pole radiofrequency trap that examined reactions take place. For capturing ions in the trap, they need to be well focused in space, time and energy. To meet these conditions, it is necessary to find a suitable parameters of the source, which is used in the laboratory. The aim of this bachelor thesis is the design of optimized ion source and then using the program in LabVIEW to optimize the ion source N+ .
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Water formation in reactions of anions and/or cations with molecular hydrogen at low temperature
Tran, Thuy Dung ; Plašil, Radek (advisor)
In the present work, the results of the experimental study of reactions of ions with molecular hydrogen in the temperature range 15 - 300 K using a 22-pole ion trap apparatus are presented. The reaction of OD- with para-enriched hydrogen was studied using a combination of the 22-pole ion trap apparatus with a para-hydrogen generator. Also reactions of O- with H2, D2, and HD were studied. These reactions have a channel of water production and a channel of hydrogen or deuterium transfer. Another field of study was a sequence of reactions of oxygen hydride cations with H2 and D2 which leads to the production of H3O+ or its isotopic variant, specifically reactions OH+ with H2, H2O+ with H2, D2O+ with H2, and D2O+ with D2. This reaction chain can be followed by the electron recombination of H3O+ or its isotopologue, which has a channel of water production.
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Water formation in reactions of anions and/or cations with molecular hydrogen at low temperature
Tran, Thuy Dung ; Plašil, Radek (advisor)
In the present work, the results of the experimental study of reactions of ions with molecular hydrogen in the temperature range 15 - 300 K using a 22-pole ion trap apparatus are presented. The reaction of OD- with para-enriched hydrogen was studied using a combination of the 22-pole ion trap apparatus with a para-hydrogen generator. Also reactions of O- with H2, D2, and HD were studied. These reactions have a channel of water production and a channel of hydrogen or deuterium transfer. Another field of study was a sequence of reactions of oxygen hydride cations with H2 and D2 which leads to the production of H3O+ or its isotopic variant, specifically reactions OH+ with H2, H2O+ with H2, D2O+ with H2, and D2O+ with D2. This reaction chain can be followed by the electron recombination of H3O+ or its isotopologue, which has a channel of water production.
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Water formation in reactions of anions and/or cations with molecular hydrogen at low temperature
Tran, Thuy Dung ; Plašil, Radek (advisor) ; Španěl, Patrik (referee) ; Rubovič, Peter (referee)
In the present work, the results of the experimental study of reactions of ions with molecular hydrogen in the temperature range 15 - 300 K using a 22-pole ion trap apparatus are presented. The reaction of OD- with para-enriched hydrogen was studied using a combination of the 22-pole ion trap apparatus with a para-hydrogen generator. Also reactions of O- with H2, D2, and HD were studied. These reactions have a channel of water production and a channel of hydrogen or deuterium transfer. Another field of study was a sequence of reactions of oxygen hydride cations with H2 and D2 which leads to the production of H3O+ or its isotopic variant, specifically reactions OH+ with H2, H2O+ with H2, D2O+ with H2, and D2O+ with D2. This reaction chain can be followed by the electron recombination of H3O+ or its isotopologue, which has a channel of water production.
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Ion processes in gases for the trace analysis of volatile compounds in air
Spesyvyi, Anatolii ; Španěl, Patrik (advisor) ; Matejčík, Štefan (referee) ; Tichý, Milan (referee)
This thesis describes development of the new selected ion flow-drift tube mass spectrometry technique, SIFDT-MS, for online quantification of volatile organic compounds, VOCs, based on gas phase ion-molecule reactions. SIFDT-MS represents a new generation of the successfully used selected ion flow tube, SIFT- MS, analytical method. The essential extension of SIFDT-MS is the uniform electric field E applied across the flow tube reactor, thus converting it to the flow-drift tube where the ion processes can be governed by strength of field E. Newly introduces Hadamard modulation of the gate lens before the flow-drift tube enables direct ion residence, and correspondently ion-molecule reaction, time measurement that is necessary for the precise concentration calculations under variable conditions. The detailed experimental study of these processes results was carried out to form a basis of the analytical method. In order to overcome a well-known issue of SIFT-MS, when mass spectral peaks of isobaric ions overlap, the pseudoinverse matrix multiplication for isobaric mixtures was demonstrated. Finally two data mining approaches were successfully tested on the data of the fragmentation signals of seven monoterpene isomers obtained in SIFT-MS.
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Laboratory studies of ion-molecule reactions with molecular and atomic hydrogen at temperatures relevant to astrochemistry
Mulin, Dmytro ; Glosík, Juraj (advisor) ; Kotrík, Tomáš (referee) ; Španěl, Patrik (referee)
The results of the laboratory study of reaction rate coefficients of several ion- molecule reactions with atomic and molecular hydrogen and molecular deuterium at low temperatures are presented in the thesis. The reaction rate coefficients of the N+ and H+ reaction with H2 were measured with respect to the nuclear spin configuration and rotational excitation of H2. The reactions of anions were a subject of the isotope exchange and isotope effect study. The measurements of the rate coefficients of H2O and D2O formation in the reaction of O- with H2 and D2, isotope exchange reactions OH- + D2 and OD- + H2, and associative detachment and charge transfer channels of D- + H interaction were performed. Experiments were carried out using an AB-22PT instrument with an ion trap. It has producing, guiding, trapping, and detecting systems for ions and a separate source of atomic H. The cooling system allowed to measure the temperature dependencies of the reaction rate coefficients at temperatures relevant to astrochemistry (10 K - 300 K)
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Production of cold ions
Tran, Thuy Dung ; Plašil, Radek (advisor) ; Roučka, Štěpán (referee)
1 Abstract: For understanding of the evolution of chemical composition in cold interstellar gas clouds, it is necessary to study the ion-molecule reactions at temperatures from 10 K to 300 K at low pressures. The Ion Trap equipment, which is available in the laboratory of the Department of Surface and Plasma Science, allows this type of experiment. The main element of the Ion Trap is a 22-pole radiofrequency trap that examined reactions take place. For capturing ions in the trap, they need to be well focused in space, time and energy. To meet these conditions, it is necessary to find a suitable parameters of the source, which is used in the laboratory. The aim of this bachelor thesis is the design of optimized ion source and then using the program in LabVIEW to optimize the ion source N+ .
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