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Precise measurement of the electron antineutrino oscillation
Pěč, Viktor ; Vorobel, Vít (advisor) ; Trávníček, Petr (referee) ; Vénos, Drahoslav (referee)
The Daya Bay experiment is designed to precisely measure short-baseline disappearance of reactor antineutrinos from reactor cores at the Daya Bay nuclear power plant complex in the Guangdong Province of China. It pre- sented the most precise measurements of oscillation parameters sin2 2θ13 = 0.084 ± 0.005 and |∆m2 ee| = (2.42 ± 0.11) × 10−3 eV2 . Background to the antineutrino signals is mainly created by cosmic muons and is effectively suppressed by use of water Cherenkov and RPC muon detectors. This thesis describe testing of RPC detectors prior to their installation at the experi- mental site. Part of the cosmic muons stop in the experiment's antineutrino detectors, and they decay or are captured by 12 C producing 12 B. Isotope 12 B contribute to accidental background. Rates of muon decays in the detectors are estimated in the thesis. The experiment can register electron antineutri- nos from supernova with expected signals around 20 MeV. Energy scale of the detectors at 53 MeV is determined.
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Monitoring of the energy scale in the KATRIN neutrino experiment
Slezák, Martin ; Vénos, Drahoslav (advisor) ; Štekl, Ivan (referee) ; Vorobel, Vít (referee)
The question of the absolute mass scale of neutrinos is of particular interest for particle physics, astrophysics, and cosmology. The KATRIN experiment (KArlsruhe TRItium Neutrino experiment) aims to address the effective electron antineutrino mass from the shape of the tritium β-spectrum with an unprecedented sensitivity of 0.2 eV/c2 . One of the major systematic effects concerns the experimental energy scale, which has to be stable at the level of only a few parts in a million. For its calibration and monitoring the monoener- getic electrons emitted in the internal conversion of γ-transition of the metastable isotope 83m Kr will be extensively applied. The aim of this thesis is to address the problem of KA- TRIN energy scale distortions and its monitoring in detail. The source of electrons based on 83m Kr embedded in a solid as well as the source based on gaseous 83m Kr are studied. Based on the experimental results an approach for the continuous stability monitoring is proposed. 1
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Zdroj monoenergetických elektronů pro monitorování spektrometru v neutrinovém experimentu KATRIN
Slezák, Martin ; Vénos, Drahoslav (advisor) ; Vorobel, Vít (referee)
The international project KATRIN (KArlsruhe TRItium Neutrino experiment) is a next- generation tritium beta decay experiment. It is designed to measure the electron antineutrino mass by means of a unique electron spectrometer with sensitivity of 0.2 eV/c2 . This is an improvement of one order of magnitude over the last results. Important part of the measurement will rest in continuous precise monitoring of high voltage of the KATRIN main spectrometer. The monitoring will be done by means of conversion electrons emitted from a solid source based on 83 Rb decay. Properties of several of these sources are studied in this thesis by means of the semiconductor gamma-ray spectroscopy. Firstly, measurement of precise energy of the 9.4 keV nuclear transition observed in 83 Rb decay, from which the energy of conversion electrons is derived, is reported. Secondly, measurement of activity distribution of the solid sources by means of the Timepix detector is described. Finally, a report on measurement of retention of 83 Rb decay product, the isomeric state 83m Kr, in the solid sources is given.
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Precise measurement of the electron antineutrino oscillation
Pěč, Viktor ; Vorobel, Vít (advisor) ; Trávníček, Petr (referee) ; Vénos, Drahoslav (referee)
The Daya Bay experiment is designed to precisely measure short-baseline disappearance of reactor antineutrinos from reactor cores at the Daya Bay nuclear power plant complex in the Guangdong Province of China. It pre- sented the most precise measurements of oscillation parameters sin2 2θ13 = 0.084 ± 0.005 and |∆m2 ee| = (2.42 ± 0.11) × 10−3 eV2 . Background to the antineutrino signals is mainly created by cosmic muons and is effectively suppressed by use of water Cherenkov and RPC muon detectors. This thesis describe testing of RPC detectors prior to their installation at the experi- mental site. Part of the cosmic muons stop in the experiment's antineutrino detectors, and they decay or are captured by 12 C producing 12 B. Isotope 12 B contribute to accidental background. Rates of muon decays in the detectors are estimated in the thesis. The experiment can register electron antineutri- nos from supernova with expected signals around 20 MeV. Energy scale of the detectors at 53 MeV is determined.
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Monitoring of the energy scale in the KATRIN neutrino experiment
Slezák, Martin ; Vénos, Drahoslav (advisor) ; Štekl, Ivan (referee) ; Vorobel, Vít (referee)
The question of the absolute mass scale of neutrinos is of particular interest for particle physics, astrophysics, and cosmology. The KATRIN experiment (KArlsruhe TRItium Neutrino experiment) aims to address the effective electron antineutrino mass from the shape of the tritium β-spectrum with an unprecedented sensitivity of 0.2 eV/c2 . One of the major systematic effects concerns the experimental energy scale, which has to be stable at the level of only a few parts in a million. For its calibration and monitoring the monoener- getic electrons emitted in the internal conversion of γ-transition of the metastable isotope 83m Kr will be extensively applied. The aim of this thesis is to address the problem of KA- TRIN energy scale distortions and its monitoring in detail. The source of electrons based on 83m Kr embedded in a solid as well as the source based on gaseous 83m Kr are studied. Based on the experimental results an approach for the continuous stability monitoring is proposed. 1
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Zdroj monoenergetických elektronů pro monitorování spektrometru v neutrinovém experimentu KATRIN
Slezák, Martin ; Vénos, Drahoslav (advisor) ; Vorobel, Vít (referee)
The international project KATRIN (KArlsruhe TRItium Neutrino experiment) is a next- generation tritium beta decay experiment. It is designed to measure the electron antineutrino mass by means of a unique electron spectrometer with sensitivity of 0.2 eV/c2 . This is an improvement of one order of magnitude over the last results. Important part of the measurement will rest in continuous precise monitoring of high voltage of the KATRIN main spectrometer. The monitoring will be done by means of conversion electrons emitted from a solid source based on 83 Rb decay. Properties of several of these sources are studied in this thesis by means of the semiconductor gamma-ray spectroscopy. Firstly, measurement of precise energy of the 9.4 keV nuclear transition observed in 83 Rb decay, from which the energy of conversion electrons is derived, is reported. Secondly, measurement of activity distribution of the solid sources by means of the Timepix detector is described. Finally, a report on measurement of retention of 83 Rb decay product, the isomeric state 83m Kr, in the solid sources is given.
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Systematic effect - angular distribution of tritium beta-particles in the KATRIN experiment
Vénos, Drahoslav ; Kašpar, Jaromír
The aim of the KATRIN project is to measure mass of the electron antineutrino with sensitivy at sub-electronvolt level. The experiment is based on the investigation of the electron spectrum of the beta-decay of tritium just at the beta-endpoint region. In this experiment the tritium cooled to low temperature is placed in the magnetic field of several tesla which causes weak but nonzero orientation of tritium nuclei and as the consequence, non-isotropic, on energy dependent, distribution of the beta-electrons.
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Studies of nuclei by means of nuclear orientation at low temperatures and in-beam spectroscopy
Vénos, Drahoslav ; Srnka, Dušan ; Zákoucký, Dalibor ; Honusek, Milan ; Mrázek, Jaromír ; van Geert, A. ; Severijns, N. ; Schuurmans, P. ; Vereecke, B. ; Versyck, S. ; Špalek, Antonín ; Bielčík, J. ; Slívová, Jana ; Adam, Jindřich
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