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RFXMod2 is an upgrade of RFXMod that will use a modified shell and mechanical structure in order to enhance plasma proximity to the shell and therefore to improve plasma control. The Control and Data Acquisition System for most of the plant systems and diagnostics previously used in RFXMod will be refurbished, while others will be completely re-built. The most important component that will be completely renewed is the Electromagnetic Probes (EM) data acquisition system. In the former system data acquisition and real-time control were implemented using two different technologies, i.e. CompactPCI and VME, respectively. In RFXMod2 a new architecture based on XILINX Zynq FPGA will be used to carry out at the same time both high-speed data acquisition and resampled data streaming for active plasma control. Moreover, numeric integration of EM signals will be carried out by the same FPGA supervising data acquisition and streaming. The use of MDSplus will be retained in RFXMod2, while the MARTe framework used for real-time plasma control will be replaced by MARTe2, a new framework developed under strict software quality standards. Plant control in RFXMod2 will be supervised by WinCC-OA, replacing the previous FactoryLink SCADA systems. Older plant units such as vacuum control using outdated S5 PLCs will be replaced by new systems, using OPC communication with the supervisory system. Old CAMAC equipment in diagnostics will be replaced by CompactPCI technology, making it uniform with the rest of the diagnostic data acquisition systems. Finally, specialized devices implemented in CAMAC such as timing sequence generators will be replaced by custom devices implemented using the same Zynq FPGA technology of the EM data acquisition devices.

Flow measurement in sewer systems is still a challenge: there is no one “the best” method which can solve all requests, but user has to optimize the selection of equipment to fulfill the existing flow and working conditions. One of the possibilities is to use the flat electromagnetic (EM) probes, presented in this paper. Flat EM probe is designed to suit the needs of sewer systems, i.e. they are robust, can operate with low velocities of few cm/s and at the same time can measure high velocities during heavy storms, can work with shallow water and even will operate if covered with sludge and sediments of reasonable height. In large flow profiles, user can easily integrate more flat EM probes into one system, improving the spatial integration of measured velocities and at the same time keeping the low overall costs. Results of laboratory investigation at Faculty of Civil Engineering in Belgrade are presented in the paper: mapping of 3D magnetic field to delineate the control volume and calculate the weighting function in real conditions, operation of probe under the heavy sediment load of different height and usage of CFD to analyze the influence of real flow filed. Few examples of flat EM probe applications are presented at the end of the paper.

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this work, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering (DVCS) off a proton bound in $^4$He. The data used here were accumulated using a $6$ GeV longitudinally polarized electron beam incident on a pressurized $^4$He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle ($\phi$) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The $Q^2$, $x_B$, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20\% to 40\%, indicating possible medium modification of its partonic structure.

In ordinary matter, quarks and gluons are confined inside hadrons by the strong interaction. At extreme conditions of temperature and energy density, a new state of matter is formed, called quark-gluon plasma (QGP). This is made of deconfined quasi-free quarks and gluons. Based on the current cosmological picture, the quark-gluon plasma was the state of our universe few $\mu$s after the Big Bang. Moreover, there is evidence that a degenerate state of matter with similar properties to the QGP exists in the inner core of neutron stars and other compact astrophysical objects. \newline \indent Microscopic and extremely short-lived quantities of such a nuclear plasma can be created in ultra-relativistic heavy ion collisions. Its properties can be studied through several experimental probes using dedicated detectors installed around the collision region. This interesting branch of research is part of the experimental program of the Large Hadron Collider (LHC) at CERN, where lead ion beams are accelerated to unprecedented energies. \newline \indent The QGP properties, in principle, can be described by Quantum-Chromo Dynamics (QCD), the quantum field theory of the strong interaction. However, a description of the system based on QCD first principles is extremely complicated due to the relatively low energy scale involved (compared to $\Lambda_{QCD}$), which does not allow to solve the QCD equations using the perturbative approach. Further complications arise from many-body properties of QCD which are anyhow extremely interesting to explore. \newline \indent The deconfined medium created in heavy-ion collisions rapidly evolves, passing through several thermodynamic stages. According to the overall picture of the space-time evolution of the collision, the system quickly approaches local thermal equilibrium. This phase is followed by a rapid expansion, which is usually described by relativistic hydrodynamics. During the system expansion, its temperature and density decrease until quarks and gluons recombine into hadrons. After hadronization, the interactions in the hot and dense gas of hadrons are described using phenomenological transport models. In this stage, the particle density further decreases until all interactions cease at the so-called freeze-out, after which the particles produced propagate freely into the vacuum. \newline \indent Photons and dileptons are unique tools to study the properties of heavy-ion collisions. These particles are continuously emitted by the expanding system, and they cross the medium with negligible final state interaction, thus carrying undisturbed information on their production source. Electromagnetic probes provide complementary information to hadronic probes, which are mostly sensitive to late stages of the collision, thus allowing to constrain the theoretical models used for the description of the system in the early stages. Thermal photons and dileptons carry information on the system temperature. Moreover, in-medium effects of short-lived vector mesons can be studied through their dilepton decay channels. Modifications of the electromagnetic spectral functions of low-mass mesons are expected in a high-temperature and high-density hadronic environment. These modifications, which are reflected in the resonance mass or width, have since long been proposed as signatures of chiral symmetry restoration. Dileptons are also sensitive to heavy-flavor production, which gives a significant contribution to the intermediate mass region of the dilepton spectrum ($m_{\phi} < m_{l^{+}l^{-}} < m_{J /\psi}$). \newline \indent In this thesis, the dielectron production in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\ \mathrm{TeV}$ with the ALICE experiment at the LHC has been studied. ALICE is the detector at the LHC dedicated to the study of heavy-ion collisions. Its excellent tracking and particle identification capabilities, over a wide range of particle momenta, make this experiment well suited for dielectron measurements. A large effort has been dedicated to the suppression of the main sources of background through innovative and efficient techniques. The main focus has been the study of the low-mass region of the dielectron invariant mass spectrum, where contributions from thermal dileptons and from in-medium modified low-mass vector mesons are expected. The fraction of virtual direct photons has been measured, which is compatible with real direct photon measurement from ALICE and existing dielectron measurements from RHIC at lower center-of-mass energy. Moreover, the measured dielectron spectrum has been compared to the expected contributions from hadron decays, thermal dileptons and in-medium modified $\rho^{0}$ and $\omega$ mesons, resulting in good agreement within the experimental uncertainties. The future perspectives for the dielectron measurement and the predicted scenario after the upgrade of the main ALICE sub-detectors are also presented.

In this paper, a contactless measuring system for the determination of the S-parameters of planar circuits is presented. With a contactless measuring system it is possible to characterise a device-under-test (DUT) embedded in a planar circuit environment without cutting the planar transmission lines connecting the DUT. The technique utilizes four identical capacitive probes in conjunction with a vector network analyser (VNA). For the usage of electromagnetic probes compared to other coupling techniques like the electro-optic probing, there is no need for expensive and complex equipment in addition to the typical equipment of a common microwave laboratory. The S-parameters are determined accurately using conventional calibration methods. A simple analytical model for the representation of the basic characteristics is developed. Furthermore, the influences on the S-parameters as a result of a variation in the coupling are presented. With the knowledge of the system characteristics, an accurate contactless measurement system is set up. The comparison between conventional and contactless measurements in a frequency range of 1–20 GHz shows a very good agreement with a phase error smaller than 1°.

In ordinary matter, quarks and gluons are confined inside hadrons by the strong interaction. At extreme conditions of temperature and energy density, a new state of matter is formed, called quark-gluon plasma (QGP). This is made of deconfined quasi-free quarks and gluons. Based on the current cosmological picture, the quark-gluon plasma was the state of our universe few $\mu$s after the Big Bang. Moreover, there is evidence that a degenerate state of matter with similar properties to the QGP exists in the inner core of neutron stars and other compact astrophysical objects.Microscopic and extremely short-lived quantities of such a nuclear plasma can be created in ultra-relativistic heavy ion collisions. Its properties can be studied through several experimental probes using dedicated detectors installed around the collision region. This interesting branch of research is part of the experimental program of the Large Hadron Collider (LHC) at CERN, where lead ion beams are accelerated to unprecedented energies.The QGP properties, in principle, can be described by Quantum-Chromo Dynamics (QCD), the theory of the strong interaction. However, a description of the system based on QCD first principles is extremely complicated due to the relatively low energy scale involved (compared to $\Lambda_{QCD}$), which does not allow a perturbative approach. Further complications arise from many-body properties of QCD which are anyhow extremely interesting to explore.The deconfined medium created in heavy-ion collisions rapidly evolves, passing through several thermodynamic stages.Photons and dileptons are unique tools to study the properties of heavy-ion collisions. These particles are continuously emitted and they cross the medium with negligible interaction, thus carrying undisturbed information on their production source.Electromagnetic probes provide complementary information to hadronic probes, allowing to constrain the theoretical models used for the description of the system in the early stages. Thermal photons and dileptons carry information on the system temperature. Moreover, in-medium modifications of low-mass vector mesons spectral functions can be studied through their dilepton decay channels. These effects have since long been proposed as signatures of chiral symmetry restoration.Dileptons are also sensitive to heavy-flavor production, which gives a significant contribution to the intermediate mass region of the dilepton spectrum ($m_{\phi} < m_{l^{+}l^{-}} < m_{J /\psi}$).In this thesis, the dielectron production in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\ \mathrm{TeV}$ with the ALICE experiment at the LHC has been studied. ALICE is the detector at the LHC dedicated to the study of heavy-ion collisions. The ALICE excellent tracking and particle identification capabilities make this experiment well suited for dielectron measurements. The main focus of this work has been the study of the low-mass region of the dielectron invariant mass spectrum, where contributions from thermal dileptons and from modified low-mass vector mesons are expected. The fraction of virtual direct photons has been measured, and the dielectron spectrum has been compared to the expected contributions from hadron decays, thermal dileptons and in-medium $\rho^{0}$ and $\omega$, resulting in good agreement within the experimental uncertainties.The future perspectives for the dielectron measurement and the predicted scenario after the ALICE upgrade are also presented.

In ordinary matter, quarks and gluons are confined inside hadrons by the strong interaction. At extreme conditions of temperature and energy density, a new state of matter is formed, called quark-gluon plasma (QGP). This is made of deconfined quasi-free quarks and gluons. Based on the current cosmological picture, the quark-gluon plasma was the state of our universe few $\mu$s after the Big Bang. Moreover, there is evidence that a degenerate state of matter with similar properties to the QGP exists in the inner core of neutron stars and other compact astrophysical objects.Microscopic and extremely short-lived quantities of such a nuclear plasma can be created in ultra-relativistic heavy ion collisions. Its properties can be studied through several experimental probes using dedicated detectors installed around the collision region. This interesting branch of research is part of the experimental program of the Large Hadron Collider (LHC) at CERN, where lead ion beams are accelerated to unprecedented energies.The QGP properties, in principle, can be described by Quantum-Chromo Dynamics (QCD), the theory of the strong interaction. However, a description of the system based on QCD first principles is extremely complicated due to the relatively low energy scale involved (compared to $\Lambda_{QCD}$), which does not allow a perturbative approach. Further complications arise from many-body properties of QCD which are anyhow extremely interesting to explore.The deconfined medium created in heavy-ion collisions rapidly evolves, passing through several thermodynamic stages.Photons and dileptons are unique tools to study the properties of heavy-ion collisions. These particles are continuously emitted and they cross the medium with negligible interaction, thus carrying undisturbed information on their production source.Electromagnetic probes provide complementary information to hadronic probes, allowing to constrain the theoretical models used for the description of the system in the early stages. Thermal photons and dileptons carry information on the system temperature. Moreover, in-medium modifications of low-mass vector mesons spectral functions can be studied through their dilepton decay channels. These effects have since long been proposed as signatures of chiral symmetry restoration.Dileptons are also sensitive to heavy-flavor production, which gives a significant contribution to the intermediate mass region of the dilepton spectrum ($m_{\phi} < m_{l^{+}l^{-}} < m_{J /\psi}$).In this thesis, the dielectron production in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76\ \mathrm{TeV}$ with the ALICE experiment at the LHC has been studied. ALICE is the detector at the LHC dedicated to the study of heavy-ion collisions. The ALICE excellent tracking and particle identification capabilities make this experiment well suited for dielectron measurements. The main focus of this work has been the study of the low-mass region of the dielectron invariant mass spectrum, where contributions from thermal dileptons and from modified low-mass vector mesons are expected. The fraction of virtual direct photons has been measured, and the dielectron spectrum has been compared to the expected contributions from hadron decays, thermal dileptons and in-medium $\rho^{0}$ and $\omega$, resulting in good agreement within the experimental uncertainties.The future perspectives for the dielectron measurement and the predicted scenario after the ALICE upgrade are also presented.

Direct photon production in heavy-ion collisions provides a valuable set of observables to study the hot QCD medium. The direct photons are produced at different stages of the collision and escape the medium unaffected. In heavy-ion collisions, the direct photon yield at high transverse momentum ( p T > 5 GeV / c ) is dominated by prompt photons produced in hard scattering of incoming partons and provides information on nuclear parton distribution functions and on the initial parton dynamics. The low momentum component ( p T ≲ 5 GeV / c ) of the direct photon production is dominated by thermal radiation by the hot and dense matter created, carrying information on its space-time evolution, collective flow and temperature. We present recent ALICE results on direct photon production Pb-Pb collisions at 2.76 TeV and on direct photon production in pp at 7 TeV using isolation techniques. The results are compared to theoretical predictions and previous measurements.

One of the commonly used approaches, for the flow measurements in open chanel hydraulic systems, is to measure one depth and use the stable Q-H relationship to compute the flow rate. If this method is inappropriate, the velocity-area method has to be used: both area (depth) and mean velocity are measured in order to compute the flow rate. Although, it is reported that the velocity sensors operate with high uncertainty, the popularity of these methods stem from the fact that they can be applied in wide range of hydraulic conditions including the mixed flow conditions. Uncertainties are related both to the applied instruments and properties of the measurement site. While Doppler probes are preffered nowadays in the hydraulic systems, electromagnetic probes have certain adventages which are found to be useful in the methodology presented in this paper. Here, so called flat EM velocity probes are analyzed, which can be used instead of Doppler probes for the flow measurements. Due to the more rigourous operating principle, particular weighting functions can be derived in order to define contributions from different parts of the flow to the measured signal. Reduction of the uncertainty can be obtained through combination of the weighting functions with site-specific velocity fields computed with CFD simulations, In order to overcome the high uncertainty issue, additional site-specific calibration procedure for flat EM sensors is presented in this paper. Concept of its application in the engineering practice example are presented. Najčešće korišćen način merenja protoka u hidrotehničkim sistemima sa otvorenim tokom je preko merenja jedne dubine i preračunavanjem u protok korišćenjem Q-H krive. U uslovima kada nije moguće jednoznačno uspostaviti Q-H vezu, neophodno je koristiti metodu Brzina-Proticajni presek, gde se odvojeno mere (srednja) proticajna brzina i dubina. Iako su dosadašnja istraživanja pokazala da senzori brzine često rade sa visokom mernom neodređenošću, ovaj pristup je popularan zbog mogućnosti primene u širokom spektru hidrauličkih problema. Merna neodređenost u obračunatom protoku ima dvojaki karakter i rezultat je neodređenosti samog merenja brzine i dubine, kao i doprinosa usled nestandardnih uslova na mernom mestu. Iako se u hidrauličkim sistemima u poslednje vreme preferiraju ultrazvučne Dopler sonde, elekromagnetne (EM) sonde poseduju prednosti u realnim uslovima rada posebno u sistemima sa otpadnim vodama. U ovom radu, analizirane su ravne EM sonde za brzinu, koje se mogu koristiti umesto Dopler sondi za merenje protoka. Zbog jasnijeg principa rada EM sondi, moguće je definisati posebne težinske funkcije kojima se opisuje koliko koji deo polja brzina utiče na izlazni signal uređaja. Koristeći težinske funkcije u kombinaciji sa modeliranim realnim strujnim poljem, dobijenim pomoću prostornih numeričkih simulacija turbulentnog toka, moguće je smanjiti mernu neodređenost uređaja. Predložena metodologija je klasifikovana kao naknadna kalibracija EM uređaja prema uslovima na mernom mestu. Koncept njene primene je prikazan kroz praktičan primer.

In this dissertation, two nondestructive dual ridged waveguide (DRWG) material characterization systems are investigated. The single and clamped DRWG probe geometries were analyzed in previous work; however, that research only incorporated the dominant DRWG mode. Here, that restriction is removed and the existence of evanescent higher- order modes is considered. Theoretical analysis of the single and clamped DRWG probes is presented and discussed. The approach taken here is similar to that presented in previous research: Love's equivalence theorem is used to remove the DRWG apertures which are replaced with equivalent magnetic currents radiating in the presence of the background parallel-plate waveguide structure. Enforcing the continuity of the tangential magnetic fields in the DRWG and parallel- plate regions yields a system of coupled magnetic field integral equations (MFIEs). This coupled MFIE system is solved using the Method of Moments (MoM) where the tangential electric and magnetic fields in the DRWG are used as expansion and testing functions, respectively. Inversion of the resulting MoM impedance matrix produces theoretical expressions for the reflection and transmission coefficients which are numerically inverted (via nonlinear least squares) to yield estimates of the permittivity and permeability of the material under test. While the steps taken in the theoretical development are similar to previous work, the addition of higher-order modes into the analysis substantially complicates the derivation and is a significant extension of the existing dominant-mode-only literature. Lastly, simulation results of the two structures are presented. A comparison of the dominant-mode only reflection and transmission coefficients with the higher-order mode coefficients is provided.