The results of the preliminary development of the HTS conductor based on the VS-type design and parallel stacks for the central solenoid of the compact thermonuclear reactor TRT are presented. One of the main problems...The results of the preliminary development of the HTS conductor based on the VS-type design and parallel stacks for the central solenoid of the compact thermonuclear reactor TRT are presented. One of the main problems that need to be solved for the successful implementation of such projects is the creation of high-current high-temperature superconducting (HTS) conductors for Toroidal Field coils (TF) and Central Solenoid (CS) sections. The conductor must have a high engineering current density of at least 90 A/mm<sup>2</sup>. The induction of the magnetic field in the central solenoid reaches 14 T, which leads to the occurrence of large mechanical stresses due to the influence of Lorentz forces. Like many large magnets, CS has a lot of stored energy. For the safe withdrawal of stored energy from the magnet, it requires the inclusion of elements in the conductor that provide an acceptable level of electrical voltage and heating of the conductor insulation. Thus, a sufficient amount of stabilizing and reinforcing materials should be placed in the conductor. In addition, the “cable-in-conduit” type of conductor must have channels for pumping the refrigerant. Two fundamentally different versions of the conductor based on radially arranged REBCO tapes and on the basis of pre-assembled tape packages are considered. Based on the analysis of the magnetic field distribution in the conductor by finite element method, the design characteristics of the proposed conductors under various operating modes of the electromagnetic system (EMS) of the tokamak TRT was evaluated. The results of the evaluation of the current carrying capacity of the conductor and the estimation of energy losses in a changing magnetic field in comparison with known methods are also presented.展开更多
In this work, water-based precursor solutions suitable for dip-coating of thick La2Zr2O7 （LZO） buffer layers for coated conductors on Ni-5%W substrates with an inclusion of polymeric polyvinyl pyrrolidone were devel...In this work, water-based precursor solutions suitable for dip-coating of thick La2Zr2O7 （LZO） buffer layers for coated conductors on Ni-5%W substrates with an inclusion of polymeric polyvinyl pyrrolidone were developed. The effect of varying percentage of the polymer addition on the preparation of the deposited films with maximum crack-free thickness was investigated. This novel water-based chemical solution deposition method involving polymers in two different chelate-chemistry compositions revealed the possibility to grow single, crack-free layers with thicknesses ranging from 140 to 280 nm, with good crystallinity and epitaxial growth. The effect of increasing polymer concentrations on the morphology and the structure of the films was studied. The appropriate buffer layer action of the films in preventing Ni diffusion was studied by X-ray photoelectron spectroscopy.展开更多
Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filte...Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filter using rectangular coaxial cables with square inner conductors, convenient for high power applications, are presented. The design of the UWB BP filter is based on the use of impedance steps and coupled-line sections. The center frequency around 6.85 GHz was selected, the bandwidth is between 3-10 GHz, the insertion-loss amounts to around 0.35 dB and the return loss is found higher than 10 dB in a large frequency range (4-9.5) GHz. The simulated results of stopband performances are better than 15 dB for a frequency range up to 11 GHz. For the selected center frequency and on a substrate with a dielectric constant of 2.03, the rectangular coaxial cables BPF with square inner conductors is only 6.7 × 8.9 × 33.4 mm in size.展开更多
文摘The results of the preliminary development of the HTS conductor based on the VS-type design and parallel stacks for the central solenoid of the compact thermonuclear reactor TRT are presented. One of the main problems that need to be solved for the successful implementation of such projects is the creation of high-current high-temperature superconducting (HTS) conductors for Toroidal Field coils (TF) and Central Solenoid (CS) sections. The conductor must have a high engineering current density of at least 90 A/mm<sup>2</sup>. The induction of the magnetic field in the central solenoid reaches 14 T, which leads to the occurrence of large mechanical stresses due to the influence of Lorentz forces. Like many large magnets, CS has a lot of stored energy. For the safe withdrawal of stored energy from the magnet, it requires the inclusion of elements in the conductor that provide an acceptable level of electrical voltage and heating of the conductor insulation. Thus, a sufficient amount of stabilizing and reinforcing materials should be placed in the conductor. In addition, the “cable-in-conduit” type of conductor must have channels for pumping the refrigerant. Two fundamentally different versions of the conductor based on radially arranged REBCO tapes and on the basis of pre-assembled tape packages are considered. Based on the analysis of the magnetic field distribution in the conductor by finite element method, the design characteristics of the proposed conductors under various operating modes of the electromagnetic system (EMS) of the tokamak TRT was evaluated. The results of the evaluation of the current carrying capacity of the conductor and the estimation of energy losses in a changing magnetic field in comparison with known methods are also presented.
基金funding under the project grants P2/00/03 (CHEMAT)IAP/VI-17(INANOMAT) and FP7-NMP-2007- SMALL-1 Grant No.205854(EFECTS)
文摘In this work, water-based precursor solutions suitable for dip-coating of thick La2Zr2O7 （LZO） buffer layers for coated conductors on Ni-5%W substrates with an inclusion of polymeric polyvinyl pyrrolidone were developed. The effect of varying percentage of the polymer addition on the preparation of the deposited films with maximum crack-free thickness was investigated. This novel water-based chemical solution deposition method involving polymers in two different chelate-chemistry compositions revealed the possibility to grow single, crack-free layers with thicknesses ranging from 140 to 280 nm, with good crystallinity and epitaxial growth. The effect of increasing polymer concentrations on the morphology and the structure of the films was studied. The appropriate buffer layer action of the films in preventing Ni diffusion was studied by X-ray photoelectron spectroscopy.
文摘Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filter using rectangular coaxial cables with square inner conductors, convenient for high power applications, are presented. The design of the UWB BP filter is based on the use of impedance steps and coupled-line sections. The center frequency around 6.85 GHz was selected, the bandwidth is between 3-10 GHz, the insertion-loss amounts to around 0.35 dB and the return loss is found higher than 10 dB in a large frequency range (4-9.5) GHz. The simulated results of stopband performances are better than 15 dB for a frequency range up to 11 GHz. For the selected center frequency and on a substrate with a dielectric constant of 2.03, the rectangular coaxial cables BPF with square inner conductors is only 6.7 × 8.9 × 33.4 mm in size.
