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Two optimization problems are formulated to improve the effectiveness and productivity of pultrusion processes, to preserve the quality of pultruded profiles, and to take into account the ambient industrial shop temperature and requirements of process technologists. To solve these problems, an optimization methodology using designed computer experiments and the response surface technique was developed. The effects of room temperature and curing allowed behind the die exit on the energy consumption and pull speed were investigated. A more accurate and realistic process optimization was achieved by the temperature control strategy with heater switch-on and -off operations. This indirect optimization methodology allowed us to develop interactive technological maps on the basis of an accessible-to-all Excel code for technologists working in industrial shops. As an example, demonstrating the effectiveness of the methodology developed and utilization of the interactive technological map, the optimization of a real pultrusion process, producing two rod profiles with ears simultaneously, is carried out.

For the real time characterization of pultrusion processes with a complex temperature control, two finite-element modeling approaches utilizing a continuous model with lumped material properties for a cured composite have been developed. The first procedure, based on the mixed time integration scheme and the nodal control volumes method, is working in the ANSYS Mechanical environment, but the second procedure is performed using the ANSYS CFX software with the cure reaction introduced as an additional variable. New cure sensors measuring the temperature and electrical resistivity of resins have been developed for the inline process control. To demonstrate the accuracy and reliability of the numerical procedures and new sensors, two technological processes with a temperature control examining the pultrusion of I-beam and rod profiles have successfully been analyzed.

This article addresses the issues of volume integral equation method application to magnetic system calculations. The main advantage of this approach is that in this case finding the solution of equations is reduced to the area filled with ferromagnetic. The difficulty of applying the method is connected with kernel singularity of integral equations. For this reason in collocation method only piecewise constant approximation of unknown variables is used within the limits of fragmentation elements inside the famous package GFUN3D. As an alternative approach the points of observation can be replaced by integration over fragmentation element, which allows to use approximation of unknown variables of a higher order.In the presented work the main aspects of applying this approach to magnetic systems modelling are discussed on the example of linear approximation of unknown variables: discretisation of initial equations, decomposition of the calculation area to elements, calculation of discretised system matrix elements, solving the resulting nonlinear equation system. In the framework of finite element method the calculation area is divided into a set of tetrahedrons. At the beginning the initial area is approximated by a combination of macro-blocks with a previously constructed two-dimensional mesh at their borders. After that for each macro-block separately the procedure of tetrahedron mesh construction is performed. While calculating matrix elements sixfold integrals over two tetrahedra are reduced to a combination of fourfold integrals over triangles, which are calculated using cubature formulas. Reduction of singular integrals to the combination of the regular integrals is proposed with the methods based on the concept of homogeneous functions. Simple iteration methods are used to solve non-linear discretized systems, allowing to avoid reversing large-scale matrixes. The results of the modelling are compared with the calculations obtained using other methods.

This paper presents a numerical simulation-based study that evaluates the potential of an active phase change material (PCM) incorporated thermal energy storage (TES) system for space cooling in residential buildings. In the proposed concept, TES system is composed of stand-alone PCM storage units which are installed between the concrete ceiling slab and the ceiling finishing layer. Active control of the thermal energy storage is achieved by night cooling of a phase change material by means of cold water flowing within a capillary pipe system. Effectiveness of the system under the typical summer conditions of the Baltic States is analysed by using computational fluid dynamics (CFD) software Ansys Fluent. Results showed that installation of the active TES system has a positive effect on thermal comfort, reducing the average indoor air temperature by 6.8 °C. The outcome of this investigation would be helpful in selecting the key characteristics of the system in order to achieve the optimum performance of an active TES system for space cooling of buildings in similar climates.

Deterioration of asphalt pavements due to fatigue cracking is one of the most common highway pavement failure types. If the fatigue cracks are allowed to develop and grow, the driving comfort and safety, i.e., serviceability of the pavement, decreases. Pavement fatigue behaviour is not a straightforward mechanism and involves many factors and effects, thus computational methods are developed in order to help understand how the pavement works. This paper explores the accuracy and applicability of a less computational resource demanding procedure that uses transient material mechanical behaviour to model the long-term behaviour of a pavement structure. First, the mechanical and fatigue properties of asphalt were determined at the laboratory. Then a four-layer finite-element model was created using Ansys software. Two different models – with and without infinity elements – and two different fatigue simulation procedures – full and simplified – were considered. Material parameters were obtained by the laboratory tests and material properties degraded over time. Cyclic surface loading was applied to simulate the passing of a truck – 6 million fatigue cycles were simulated.

To demonstrate features and benefits of electromagnetic energy source, the heating of rod profile made of polyester resin POLRES 305BV and glass fibres 4800 tex in cylindrical cavity resonator was studied. Materials with different dielectric properties: zirconium dioxide, boron nitride and quartz glass for a microwave transparent die were selected and analysed. The optimal diameter of ceramic die providing an effective and uniform electric field in the composite profile was found for each material.

The magnetic system of the NICA collider includes 80 twin-aperture superconducting dipole magnets. Measurements of the magnetic-field parameters should be done for both apertures of each collider magnet. This paper describes the methods, the first results of magnetic measurements, and developments of a dedicated system for mass-produced dipole magnets of the NICA collider.

A 64-channel readout and data-acquisition module is described in detail. It consists of an H12700 multianode photomultiplier tube, four PADIWA preamplifier boards, and a TRB v3 card that perform the functions of a time-to-digital converter and a data concentrator. The software modules that are necessary for operation of the prototype are described. The inter-channel delays are calibrated. The drift of individual delays does not exceed 0.5 ns for the entire measurement time. The spectra of the “time over threshold” (ToT) are investigated. The influence of periodic noise pickups and the need to improve circuit designs are revealed. The timing properties of the wavelength shifter and its effect on the detection efficiency for Cherenkov rings are investigated. The most intense component is characterized by a decay time of 1.1 ns and there are components with characteristic times of 3.8 and 45 ns. The influence of single-electron spectrum features on the detection efficiency for photoelectrons and the probability of false hits are determined. The total time resolution of 131 channels is 1.1 ns (FWHM). The results make it possible to use the investigated system of readout and data acquisition in the CBM experiment. Nevertheless, the elimination of the revealed shortcomings will provide the efficiency margin and improve the reliability of the system during long-term operation.

Pultrusion is a technological process in which fibers impregnated with resin move through the heated die and solidify into a composite profile with a constant cross section, as in the metallic die. The effectiveness and productivity of conventional pultrusion processes, preserving the quality of pultruded profiles, could be improved by process optimization or by the application of new, effective heating sources instead of electrical resistances with high heat losses. Due to the large dimension of the numerical problem and multiple iterations applied for the solution of government equations, an optimization methodology was developed, using the method of experimental design and the response surface technique. To develop microwave-assisted pultrusion processes, as well as pultrusion tooling design and process control, new effective electromagnetic-thermo-chemical finite element models and algorithms were developed by using general-purpose finite element software that results in considerable savings in development time and costs and makes available various modeling features of the finite element packages. The effectiveness and productivity of the optimized conventional pultrusion processes and the developed microwave-assisted pultrusion processes are estimated in comparison with the real pultrusion processes used in laboratory and industrial shops.

The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) will investigate the phase diagram of strongly interacting matter at high net-baryon density and moderate temperature in A+A collisions. One of the key detectors of CBM to explore this physics program is a Ring Imaging CHerenkov (RICH) detector for electron identification. For a high performance of the RICH detector precise mirror alignment is essential. A three-step correction cycle has been developed, which will be discussed: First a qualitative, fast check of the mirror positions, second a quantitative determination of possible misalignments and third a software correction routine, allowing a proper functioning of the RICH under misalignment conditions.

The CBM-RICH detector is designed to identify electrons with momenta up to 8 GeV/c and high purity as this is essential for the CBM physics program. The detector consist of a CO2-gaseous radiator, a spherical mirror system, and Multi-Anode PhotoMultiplier Tubes (MAPMT) of type H12700 from Hamamatsu as photon detectors. The detector concept was verified through R&D studies and a laterally scaled prototype. The results were summarized in a TDR, in which open issues were defined concerning the readout electronics, the shielding of the magnetic stray field in the MAPMT region, the radiation hardness of the MAPMT sensors, and the mechanical holding structure of the mirror system. In this article an overview is given on the CBM RICH development with focus on those open issues.

The Compressed Baryonic Matter (CBM) experiment at the future FAIR facility will investigate the QCD phase diagram at high net baryon densities and moderate temperatures in A+A collisions from 2 to 11 AGeV (SIS100). Electron identification in CBM will be performed by a Ring Imaging Cherenkov (RICH) detector and Transition Radiation Detectors (TRD). A real size prototype of the RICH detector was tested together with other CBM groups at the CERN PS/T9 beam line in 2014. For the first time the data format used the FLESnet protocol from CBM delivering free streaming data. The analysis was fully performed within the CBMROOT framework. In this contribution the data analysis and the event reconstruction methods which were used for obtained data are discussed. Rings were reconstructed using an algorithm based on the Hough Transform method and their parameters were derived with high accuracy by circle and ellipse fitting procedures. We present results of the application of the presented algorithms. In particular we compare results with and without Wavelength shifting (WLS) coating.

The CBM RICH detector is an integral component of the future CBM experiment at FAIR, providing efficient electron identification and pion suppression necessary for the measurement of rare dileptonic probes in heavy ion collisions. An overview of the CBM RICH readout and DAQ system prototype is given, consisting of the PADIWA preamplifier-discriminator board, the TDC-HUB board TRBv3, and DAQ and analysis code in the CbmRoot framework. The laboratory setup built for studying the timing characteristics of the readout chain and the analysis results obtained using the laboratory measurements are presented. The fine time calibration and inter-channel delay correction techniques and their implementation and effect are discussed.

Traditional description of the rate of the thermoset resin reaction by the Arrhenius relationship multiplied by a reaction function has been used in this study. The Kissinger method and ASTM E 698 procedure have been used for a determination of parameters of the Arrhenius relationship. N-th order, Prout-Tompkins and Kamal-Sourour models have been used and evaluated as the reaction functions to formulate the curing kinetic models of an epoxy resin.An engineering tool based on Microsoft Excel code has been developed by using the developed methodology. This tool has been successfully applied for a building of the curing kinetic model of vinyl ester resin with high microwave absorption properties to be used in the microwave assisted pultrusion processes.

Pultrusion is a continuous and cost-effective process for a production of composite structural components with a constant cross-sectional area. To provide better understanding of the pultrusion processes, to support the pultrusion tooling design and process control, as well as to increase a reliability of the simulation results, two alternative finite element modeling approaches using the same continuous model with lumped material properties for the cured composite are developed, compared, and discussed. Each of them is constructed using the general-purpose finite element software ANSYS that results in considerable savings in development time and costs, and also makes available various modeling features of the finite element package. The first procedure is developed in ANSYS Mechanical environment and is based on the mixed time integration scheme and nodal control volumes method to decouple the coupled energy and species equations. The second procedure is performed using ANSYS CFX software with th...

Nuclotron-based Ion Collider fAcility (NICA) is a new accelerator collider complex under construction at the Joint Institute for Nuclear Research. The facility is aimed at providing collider experiments with heavy ions up to Gold in the center of mass energy from 4 to 11 GeV/u and an average luminosity up to 1 · 10 27 cm -2 s -1 for Au 79+ . The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting booster synchrotron, the existing 6-AGeV superconducting synchrotron Nuclotron, and a new superconducting collider consisting of two rings, each 503 m in circumference. The booster synchrotron and the NICA collider are based on an iron-dominated “window frame”-type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the serial production and test of the magnets for the booster synchrotron and the development of the full-size model magnets for the NICA collider is presented. The test results of magnets are discussed. The status of the construction of the facility for serial tests of superconducting magnets for the NICA project is described.

In 2015 1100 Multi-Anode Photo-Multipliers (MAPMTs) of type HAMAMATSU H12700 were ordered to equip the photon detection plane of the CBM-RICH and HADES-RICH detectors. Both experiments aim to study the properties of dense matter produced in heavy ion collisions. To measure the characteristics of all ordered MAPMTs and give feedback to the manufacturer, a test bench was built at the University of Wuppertal. This paper describes the working principle of the test bench and compiles the measurements of the first 400 H12700 MAPMTs delivered. The average characteristics of the H12700 gathered from these measurements are discussed and compared to measurements of the HAMAMATSU H8500.

A real size prototype of the CBM RICH detector was tested in beam at CERN in November 2014 with new readout electronics. A detailed analysis of the timing characteristics of the readout chain will be presented in this article. Results of the time precision measurements for several subsets of all channels and the stability of the fine time calibration will be discussed. The obtained sub-nanosecond time precision allows also to investigate the effect on timing when using additional wavelength-shifting films on top of the MAPMT windows.

The paper presents a parametric analysis and design optimisation of an active PCM thermal energy storage system for space cooling of nearly zero-energy buildings. The design for a new space cooling system proposes a TES system composed of stand-alone PCM storage units incorporated into the building interior under the ceiling slab. Active control of the thermal energy storage is realized by night cooling of a phase change material by means of cold water flowing within a capillary pipe system. The objective of the study is to examine the effect of the system’s main parameters such as PCM layer thickness, number of parallel pipes, diameter of pipes, night cooling duration, cooling water inlet temperature and velocity under Baltic summer weather conditions. Parametric analysis is performed by using computational fluid dynamics software Ansys Fluent. Optimisation of the main parameters is carried out to determine the best combination of their values ensuring the system is able to absorb the daily thermal loads within the room and operates with minimum energy consumption for the night cooling of PCM.

For in-line characterization of pultruded profiles, two alternative ANSYS based finite element modelling approaches using the same continuous model with lumped material properties for the cured composite are developed, compared and discussed. The first procedure is developed in ANSYS Mechanical environment and based on the mixed time integration scheme and nodal control volumes method. The second procedure is performed by using ANSYS CFX software with the cure reaction introduced as an additional variable. Validation of the developed algorithms is realized by the analysis of pultrusion process for the rod profile controlled in-line by new cure sensors measuring the temperature and electrical resistivity of the resin on the profile surface.For in-line characterization of pultruded profiles, two alternative ANSYS based finite element modelling approaches using the same continuous model with lumped material properties for the cured composite are developed, compared and discussed. The first procedure is developed in ANSYS Mechanical environment and based on the mixed time integration scheme and nodal control volumes method. The second procedure is performed by using ANSYS CFX software with the cure reaction introduced as an additional variable. Validation of the developed algorithms is realized by the analysis of pultrusion process for the rod profile controlled in-line by new cure sensors measuring the temperature and electrical resistivity of the resin on the profile surface.

Summary In this paper, a mode shape curvature-based method for detection and localization of damage in plate-like structures is described. The proposed algorithm requires only the mode shape curvature data of the damaged structure. The damage index is defined as the absolute difference between the measured curvature of the damaged structure and the smoothed polynomial representing the curvature of the healthy structure. To examine the advantages and limitations of the proposed method, several sets of numerical simulations are carried out. Simulated test cases considering different levels of damage severity, measurement noise and sensor sparsity are studied to evaluate the robustness of the method under the noisy experimental data and limited sensor data. Applicability and effectiveness of the proposed damage detection method are further demonstrated experimentally on an aluminium plate containing mill-cut damage. The modal frequencies and the corresponding mode shapes are obtained via finite element models for numerical simulations and by using a scanning laser vibrometer for the experimental study. Copyright © 2016 John Wiley & Sons, Ltd.

A 2-dimensional wavelet transform algorithm employing isotropic Pet Hat wavelet is used to locate the area of damage in a numerically simulated aluminium plate model. To study the advantages and limitations of proposed method, signals of vibrational mode shapes of the plate are reduced by integer numbers to study the performance of algorithm at various sensor densities. Results suggest that the lowest scale of selected wavelet function yields the best damage identification results with a damage location likelihood of more than 98%.

In this paper an on-going research effort aimed at detecting and localizing damage in plate-like structures by using mode shape curvature based damage detection algorithm is described. The proposed damage index uses exclusively mode shape curvature data from the damaged structure. This method was originally developed for beam-like structures. In this paper, the method is generalized to plate-like structures which are characterized by two-dimensional mode shape curvature. To calculate mode shape curvatures from the measured mode shapes, three approaches are proposed: the first one is the well-known central difference approximation, the other two are classical approaches based on Tikhonov's regularization technique with smoothing functional. The applicability and effectiveness of the proposed damage detection algorithms are demonstrated experimentally on an aluminium plate containing mill-cut damage. The validity of the method is assessed by comparing the identification results of the experimental test case to the results obtained from the simulated test case. The modal frequencies and the corresponding mode shapes of the aluminium plate are obtained via finite element models for numerical simulations and by using a scanning laser vibrometer (SLV) for the experimental study.

The volume integral equation method is considered for magnetic systems. New modeling results are reported.

The paper describes on-going research effort at detecting and localizing damage in plate-like structures using mode shape curvature based damage detection algorithm. The proposed damage index uses data on exclusively mode shape curvature from the damaged structure. This method was originally developed for beam-like structures. The article generalizes the method of plate-like structures characterized by two-dimensional mode shape curvature. To examine limitations of the method, several sets of simulated data are applied and the obtained results of the numerical detection of damage are validated by comparing them with the findings of the case of the experimental test. The simulated test cases include the damage of various levels of severity. In order to ascertain the sensitivity of the proposed method for noisy experimental data, numerical mode shapes are corrupted with different levels of random noise. Modal frequencies and corresponding mode shapes of an aluminium plate containing mill-cut damage are obtained via finite element models for numerical simulations and by using a scanning laser vibrometer (SLV) for the experimental study.

Optimisation methodology for composite repair systems of transmission pipelines with volumetric surface defects is presented. Due to large dimension of the numerical tasks to be solved, this methodology is developed employing the method of experimental design and response surface technique. To bring an efficiency of damaged section up to the level of undamaged pipeline, two optimisation problems based on equivalently resistant (equiresistant) and minimum weight designs are formulated and solved in the present study. Features, advantages and limitations of both approaches are discussed in their applicability for the optimal design of composite repair systems of transmission pipelines.

Universal non-destructive techniques, adapted or developed for an effective and accurate characterisation of mechanical properties of composite materials, used in the advanced repair systems of pipelines with volumetric surface defects, are presented. There is static approach using three-points-bending tests and two dynamic methods: impulse excitation and inverse technique based on low-frequency vibrations. An experimental evaluation of the elastic material properties of laminated composites has allowed to validate the examined non-destructive techniques, to demonstrate their simplicity and reliability as well as to define their advantages and limitations.

Wavelength-shifting (WLS) films of p-terphenyl have been applied by means of dip-coating on the entrance window of the H12700 multi anode photomultiplier (MAPMT) in order to enhance the UV sensitivity. Using coated and uncoated MAPMTs in a CBM RICH testbox in a proton testbeam at the COSY accelerator, an enhancement of the number of hits per ring of 15%–20% depending on cuts has been observed. Due to new fast readout electronics of the RICH detector for the CBM/ HADES experiments, the time response of p-terphenyl has been measured to show a decay constant of 2.35 ns. This compares well with time-resolved fluorescence measurements of the films.

The upgraded HADES RICH detector, as well as the future CBM RICH detector, will both use the same Hamamatsu H12700 Multianode PMTs read out by the newly developed DiRICH FPGA-TDC readout chain for MAPMTs and MCPs. The upgrade of the HADES RICH photon detector has meanwhile been completed, and we are now looking forward to the upcoming physics run in spring 2019. A brief overview on the status of both detector projects is given and supplemented with the recent test-beam results which confirmed the functionality of the DiRICH development before the start of the mass-production of all DiRICH components needed for the HADES RICH upgrade.

The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) complex will explore the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions. The energy spectrum will start at 2 AGeV/c and extend up to 11 AGeV/c for the heaviest nuclei at the SIS 100 accelerator set-up. To explore the physics program of CBM, a RICH detector will be employed for electron identification and pion suppression in a momentum range up to 8 GeV/c. Mirror alignment is a key issue for a proper detector operation. The final conceptual design for a monitoring system of the alignment of the mirrors of the CBM RICH detector will be introduced. It consists of a fast qualitative check of the alignment as well as two different methods to derive quantitative numbers for misalignments. A software correction cycle had been developed which, once applied allows to get back to physics performances as in an ideally aligned case.

NICA is a new accelerator collider complex under construction at JINR. The facility is aimed at providing collider experiments with heavy ions up to Uranium in a center of mass energy range from 4 to 11 GeV/u and an average luminosity up to 1027 cm -2 s-1. The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting booster synchrotron, the existing 6 AGeV superconducting synchrotron Nuclotron, and a new superconducting collider consisting of two rings, each of about 500 m in circumference. The booster synchrotron and the NICA collider are based on an iron-dominated “window frame”-type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the development of the full size model magnets for the booster synchrotron as well as for the NICA collider is presented. The test results of model magnets are discussed. The status of the creation of a facility for serial tests of superconducting magnets for the NICA project is described.

In this paper, effectiveness of phase change materials (PCMs) for application in passive thermal energy storage (TES) system for space cooling in residential buildings is investigated numerically. PCM is encapsulated in steel containers and integrated into the building interior under a ceiling slab. Thermal response of two phase change materials with different melting/solidification temperatures under the typical summer conditions of the Baltic States is analysed by using computational fluid dynamics (CFD) software Ansys Fluent. The results showed that integration of the passive TES system can reduce the overheating problem and improve thermal comfort; however full advantage of the PCM storage capacity cannot be taken without active regeneration of the PCM.

XXIII International Baldin Seminar on High Energy Physics Problems, Baldin ISHEPP XXIII, Dubna, Russia, 19 Sep 2016 - 24 Sep 2016; The European physical journal / Web of Conferences 138, 12001 - (2017). doi:10.1051/epjconf/201713812001, The scientific goal of the CBM (Compressed Baryonic Matter) experiment at FAIR (Darmstadt) is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The 5.15 MJ superconducting dipole magnet will be used in the silicon tracking system of the CBM detector. The magnet will provide a magnetic field integral of 1 Tm which is required to obtain a momentum resolution of 1% for the track reconstruction. The results of the development of dipole magnet of the CBM experiment are presented., Published by EDP Sciences, Les Ulis

International audience; Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 ( $\sqrt{s_{NN}}=$ 2.7--4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials ( $\mu_B > 500$ MeV), effects of chiral symmetry, and the equation of state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2024, in the context of the worldwide efforts to explore high-density QCD matter.

NICA is the new accelerator complex being under design and construction at JINR. The facility is aimed at providing collider experiments with heavy ions up to Uranium in a center of mass energy range from 4 to 11 GeV/u and an average luminosity up to 1027 cm-2 · s-1. The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting Booster synchrotron, the existing 6 A · GeV superconducting synchrotron-Nuclotron, and the new superconducting Collider consisting of two rings of about 500 m circumference each. The Booster synchrotron and the NICA Collider are based on an iron-dominated “window frame”- type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the design and construction of the full size model magnets for the Booster synchrotron as well as for the NICA Collider is presented.

The SIS 100 synchrotron is based on Nuclotron type superconducting magnets. These are operated with 4 T/s up to a maximum field of 2 Tesla (dipoles). Based on the experience of the R&D period three full scale dipoles as well as one quadrupole were built. The first dipole was tested intensively this year. We present the operation performance of the first magnet next to the AC losses and apply a concise description of the magnetic field within the complete elliptical beam pipe. We analyse the static and dynamic field quality of the dipoles and compare them to the calculated ones. These test results allow us describing the parameters of the final dipole design for the machine and the field distortions the vacuum chamber creates along with investigations to reduce these artefacts. Based on our preliminary theoretical R&D and the recent measurement results we conclude on the expected operation parameters of an optimized curved dipole with a high current single layer coil and we describe the actual work topics for this magnet.

Standard textbooks on beam dynamics study the impact of the magnetic field quality on the beam using field representations based on circular multipoles. Iron dominated magnets, however, typically provide a good field region with a non-circular aspect ratio (i.e. an ellipse whose axis a is significantly larger than the axis b); a boundary not ideal for circular multipoles. The development of superconductors, originally driven to reach fields above ≈ 2 T , allows using them today in completely different fields: iron dominated DC magnets, to save the energy for coil powering as well as repeatedly fast ramped magnets. The cold mass of magnets, housed in common cryostats sectors, makes it tedious to implement additional correction magnets at a later stage, as it requires to warm up the sections where the magnets should be installed as well as unwelding the cryostat. Thus the field homogeneity of the magnets and its influence on the beam has to be thoroughly studied during the project planning phase. Elliptic multipoles, a new type of field expansion for static or quasi-static (here magnetic) two-dimensional fields, are proposed and investigated, which are particular solutions of the potential equation in plane elliptic coordinates obtained by the method of separation. The proper subsets of these particular solutions appropriate for representing static real or complex fields regular within an ellipse are identified. Formulas are given for computing expansion coefficients from given fields. The advantage of this new approach is that the expansion is valid, convergent and accurate in a larger domain, namely in an ellipse circumscribed to the reference circle of the common circular multipoles in polar coordinates. Formulas are derived for calculating the circular multipoles from the elliptical ones. The effectiveness of the approach was tested on many different magnet designs and is illustrated here on the dipole design chosen for the core synchrotron (SIS 100) of the FAIR project as well as on measurement data obtained by rotating coil probes.

PurposeThe purpose of this paper is to present new basis functions suitable to parameterize two‐dimensional static potentials or (magnetic) fields and to show their application in practical cases.Design/methodology/approachRegular multipole solutions of the potential equation in plane elliptic coordinates are found by separation. The resulting set of functions is reduced to complete subsets suitable for expanding regular potentials or irrotational source‐free fields. Approximate regular plane solutions of the potential equation in local toroidal coordinates are computed by R‐separation and power series expansions in the inverse aspect ratio. The harmonic signals induced in a coil rotating in such a toroidal multipole field are computed from the induction law by similar expansions.FindingsThe elliptic expansions are useful in a larger area than circular multipole expansions and give better fits. The toroidal expansions permit one to estimate the effect of the curvature of magnets on the field and give better adapted expansions. However, while the scalar multipoles for the potential are orthogonal the vector fields derived for the two‐dimensional field are not.Research limitations/implicationsDerivations presuppose analytical fields.Practical implicationsField data obtained from numeric field calculations or measurements do not represent exactly analytic fields. Application of the expansion requires care and checks.Originality/valueThe paper presents novel approaches for parameterizing longitudinally uniform cylindrical or toroidally uniform potentials and fields.

The problem of optimization of the two-dimensional magnetic field distribution of a dipole magnet with a field of 4 T and aperture diameter of 100–110 mm for a fast cycling synchrotron is considered. A singlelayer winding with a small number of turns is made from a hollow NbTi superconducting cable with an operating current up to 30 kA. The mathematical method providing optimization of the higher harmonics amplitude of the magnetic field by varying the position of current windings is described. The results of calculation of two-dimensional magnetic fields of the superconducting magnet are given.

We applied a nonlinear time series analysis to the traffic measurements, obtained at the input of a medium size local area network. In order to reconstruct the underlying dynamical system, we estimated the correlation length s and the embedding dimension dE of the traffic time series. In order to extract the regular part from traffic data, we filtered out the high frequency, ‘‘noisy’’ part. The reliable values of s and dE permitted to apply a layered neural network for the identification and reconstruction of the underlying dynamical system. 2002 Elsevier Science Ltd. All rights reserved.

We applied a nonlinear time series analysis approach to the traffic measurements obtained at the input of a medium size local area network. In order to reconstruct the underlying dynamical system, we estimated the correlation length and the embedding dimension of the traffic series. The estimated embedding dimension, based on the Grassberger–Procaccia algorithm, is high. In order to extract the regular part from traffic data and to decrease the system's dimension, we filtered out a high-frequency, “ noisy ” part, applying the wavelet filtering. Using the principal components analysis (PCA), we estimated the number of feature components in the traffic series. The reliable values of the correlation length and the embedding dimension provided the application of a layered neural network for identification and reconstruction of the dynamical system. We have found that the trained neural network reproduces the statistical features of real measurements and confirms the PCA result on the dimension of the traffic series.

An essential part of the DiMuon Arm Spectrometer of the ALICE experiment is a conventional Dipole Magnet of about 890 tons which provides the bending power to measure the momenta of muons. The JINR engineering design of the Dipole Magnet, technical characteristics and description of the proposed manufacturing procedure are presented. The proposed Coil fabrication technique is based on winding of flat pancakes, which are subsequently bent on cylindrical mandrels. The pancakes are then stacked and cured with prepreg insulation. The method is demonstrated on hand of the prototype II, which consists of a pancake made with full-size aluminium conductor. Some details of electromagnetic and mechanical calculations are described. The results of measuring of mechanical and electrical characteristics of materials related to the coil composite structure are discussed.

We investigate the ability of artificial neural networks to reconstruct discrete chaotic maps with singular points. We use as a simple test model the Cusp map. We compare the traditional Multilayer Perceptron, the Chebyshev Neural Network and the Wavelet Neural Network. The numerical scheme for the accurate determination of a singular point is also developed. We show that combining a neural network with the numerical algorithm for the determination of the singular point we are able to accurately approximate discrete chaotic maps with singularities.