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Effect of the laser pulse illumination on charge collection efficiency in radiation detectors.
Betušiak, Marián ; Belas, Eduard (advisor)
The main focus of this thesis is the characterization of the charge transport in CdZnTe radiation detectors and the study of the effect of the detector illumination on charge transport. The transport properties are evaluated using Laser-induced Transient Current Technique and the Monte Carlo simulation is used for fitting the measured current waveforms. The properties of the detector prepared from semi-insulating CdZnTe single crystal with a platinum Schottky contacts were measured in the dark in the unpolarized and polarized state and under the anode and cathode continuous LED above-bandgap illumination.
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Electrical and optical properties of SiC single crystals
Brynza, Mykola ; Belas, Eduard (advisor)
Silicon carbide is a semiconductor with a wide bandgap of up to 3.2 eV and is capable of operating in extreme conditions, high temperature and high energy modes. This work focuses on the investigation of electrical and optical properties of monocrystalline SiC by various methods including Raman spectroscopy, volt-ampere characteristics, L-TCT and spectroscopic techniques. The adhesion of contacts and the influence of different contact materials on the ability to detect ionizing radiation are also studied to optimize the technology of preparation of quality SiC-based radiation detectors.
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Electrical and optical properties of SiC single crystals
Brynza, Mykola ; Belas, Eduard (advisor) ; Štekl, Ivan (referee)
Silicon carbide is a semiconductor with a wide bandgap of up to 3.2 eV and is capable of operating in extreme conditions, high temperature and high energy modes. This work focuses on the investigation of electrical and optical properties of monocrystalline SiC by various methods including Raman spectroscopy, volt-ampere characteristics, L-TCT and spectroscopic techniques. The adhesion of contacts and the influence of different contact materials on the ability to detect ionizing radiation are also studied to optimize the technology of preparation of quality SiC-based radiation detectors.
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Effect of the laser pulse illumination on charge collection efficiency in radiation detectors.
Betušiak, Marián ; Belas, Eduard (advisor) ; Oswald, Jiří (referee)
The main focus of this thesis is the characterization of the charge transport in CdZnTe radiation detectors and the study of the effect of the detector illumination on charge transport. The transport properties are evaluated using Laser-induced Transient Current Technique and the Monte Carlo simulation is used for fitting the measured current waveforms. The properties of the detector prepared from semi-insulating CdZnTe single crystal with a platinum Schottky contacts were measured in the dark in the unpolarized and polarized state and under the anode and cathode continuous LED above-bandgap illumination.
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Effect of the laser pulse illumination on charge collection efficiency in radiation detectors.
Betušiak, Marián ; Belas, Eduard (advisor) ; Oswald, Jiří (referee)
The main focus of this thesis is the characterization of the charge transport in CdZnTe radiation detectors and the study of the effect of the detector illumination on charge transport. The transport properties are evaluated using Laser-induced Transient Current Technique and the Monte Carlo simulation is used for fitting the measured current waveforms. The properties of the detector prepared from semi-insulating CdZnTe single crystal with a platinum Schottky contacts were measured in the dark in the unpolarized and polarized state and under the anode and cathode continuous LED above-bandgap illumination.
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Electrical and optical properties of SiC single crystals
Brynza, Mykola ; Belas, Eduard (advisor) ; Štekl, Ivan (referee)
Silicon carbide is a semiconductor with a wide bandgap of up to 3.2 eV and is capable of operating in extreme conditions, high temperature and high energy modes. This work focuses on the investigation of electrical and optical properties of monocrystalline SiC by various methods including Raman spectroscopy, volt-ampere characteristics, L-TCT and spectroscopic techniques. The adhesion of contacts and the influence of different contact materials on the ability to detect ionizing radiation are also studied to optimize the technology of preparation of quality SiC-based radiation detectors.
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Study of the charge collection efficiency affected by metalization in Gamma and X- ray detectors
Pipek, Jindřich ; Belas, Eduard (advisor) ; Grill, Roman (referee)
In this thesis, the influence of metal contacts, prepared on CdZnTe-based semiconductor material by electroless deposition using aqueous or alcohol based solution, on the detection quality of Gamma and X-ray detectors. The quality of metal contacts is also affected by surface treatments. From single crystal of CdZnTe the testing detector was made. Electrical, spectroscopic and optical characterization techniques were used and their results were compared for two mentioned types of contacts. The aim was to show the possibility of preparing high quality metal contacts prepared from alcohol based solution of Gold(III) chloride. Alcohol based contacts are new method for preparing chemical contacts and promise different properties from standard chemical contacts prepared from aqueous based solution of Gold(III) chloride.
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Devices of radiation protection on the new nuclear source
LEŠTINA, Lukáš
The aim of the bachelor thesis is mapping the market with portable radiation protection devices offered by manufacturers specialized in nuclear measurement electronics, like Thermo Scientific, Canberra Packard and VF Černá Hora and subsequent comparison of for the purpose of finding operationally optimal solution of portable instrument for measurement of radiation quantities on a new nuclear source. At the beginning the reader is familiarized with occurrence of ionizing radiation, physical principles the instruments are based on and the radiation quantities by which the instruments interpret the final values. There is a description of the present state of portable measurement technologies used by radiation protection staff at Temelín Nuclear Plant. The description includes basic information, photos and specifications. A methodology with criteria of selection of new portable instruments was elaborated upon experience with the plant operation. Selected instruments from the large range by nuclear electronics manufacturers are described in an extra chapter. The discussion focuses on user comfort and suitability of the instruments based on the real situation of Temelín Nuclear Plant. Attention is also paid to versatility of the instruments and possibilities of their extension by additional devices like external probes of dose equivalent input, surface contamination or probes measuring dose equivalent input of neutrons. The instruments should correspond to the needs of the radiation protection staff as much as possible, so as they are able to fulfil the programme of monitoring on a new nuclear source in the most efficient manners.
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