Axion Search by Laser-based Experiment OSQAR

International audienceLaser-based experimentOSQAR in CERN is aimed to the search of the axions by twomethods. The photon regeneration experiment is using two LHC dipole magnets of the length 14.3 m and magnetic field 9.5 T equipped with an optical barrier at the end of the first magnet. It looks as light shining through the wall. No excess of events above the background was detected at this arrangement. Nevertheless, this result extends the exclusion region for the axion mass. The second method wants to measure the ultra-fine Vacuum Magnetic Birefringence for the first time. An optical scheme with electro-optical modulator has been proposed, validated and subsequently improved. Cotton-Mouton constant for air was determined in this experiment setup

XXV. mezinárodní kolokvium o regionálních vědách

Title in English: 25th International Colloquium on Regional Sciences: Conference proceedings The conference proceedings consists of papers presented at the 25th International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 57 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism, or regional public administration

Measurement of the complex permitvity materials via mutilayers dieletrics

katedra: MTI; rozsah: 70 s. (61 000 znaků)Cílem diplomové práce je návrh metody, pomocí které lze určit komplexní permitivitu neznámého dielektrika při vysokých frekvencích vloženého mezi vrstvy dvou stejných materiálů se známou dielektrickou konstantou. V práci jsou popsány dva způsoby jak stanovit komplexní permitivitu prostřední neznámé vrstvy, jednak na základě výpočtu koeficientů odrazu a prostupu, a také pomocí prvků náhradního odvodu kondenzátoru se sériově děleným dielektrikem. Metoda výpočtu komplexní permitivity z náhradního obvodu kondenzátoru byla ověřena měřením na materiálovém analyzátoru Agilent E4991A RF při kmitočtu 400MHz.The aim of this diploma thesis is to propose a method, which can be used to define complex permitivity of unknown dielectric at high frequencies inserted between the layers of two same materials with the known dielectric constant. There are two ways of defining the complex permitivity of the middle unknown layer described in this thesis. The first is based on the calculation of reflection and transmission coefficients, the second by capacitor equivalent circuit elements series divided dielectric. The method of calculating the complex permitivity is verified through the Agilent E4991A RF at frequency 400MHz

Stokes CMOS polarimetry limits studied at non-classical polarisation states

We present the study of the two polarisation state analysers. The first consists of a polarisation camera with a removable QWP, and the second consists of a non-polarisation camera with a rotating QWP and a stationary linear polariser. The theoretical analysis and experiment focus on studying the influence of polarimeter optical components accuracy and errors such as retardation errors, misalignments and extinction ratio on Stokes parameters precision. This research is a cornerstone to understanding polarisation state analysers limits. We examined laser beams with non-classical polarisation distribution, namely the Poincaré beam and the beam with radial polarisation