Search

This article reports a study to identify optimal synthesis parameters for a pure boron precursor prepared following a patented process developed at CNR-SPIN laboratories, performed in the framework of a collaboration between CNR-SPIN and CERN. Boron is a precursor that plays a crucial role in the MgB2 wire manufacturing, as a consequence, the synthesis parameters of the superconducting phase have been investigated. In this article, we report results for MgB2 samples synthesized at 870 °C for 17nbsp;h under Ar/5% H2 flow and 760 °C for 0.2 h. Magnesiothermic amorphous nanoboron (MANB) and commercial boron nanopowders (purchased from Pavezyum) have been compared in terms of morphological features. MgB2 derived from both sources has been characterized and the superconductive properties in the wire form have been compared. Results demonstrate that the MANB performance is comparable with the nanoboron obtained via gas synthesis. [ABSTRACT FROM AUTHOR]

AC losses for a wide range of ac amplitudes and frequencies have been studied in magnesium diboride (MgB2) superconducting wire with 36 filaments and Monel sheath at different temperatures and dc current levels. The results show a strong nonlinear frequency dependence below 1 kHz, which crosses over to a more moderate linear behavior at frequencies up to 18 kHz. Surprisingly, the introduction of dc current causes a significant reduction in the ac losses. Finite element simulations yield ac losses consistent with that observed experimentally. The simulations show that the magnetic Monel sheath is a dominant source for ac losses in zero dc current and that nonzero dc current saturates the magnetization, thus reducing the ac losses. [ABSTRACT FROM AUTHOR]

A three-year research project, called DRYSMES 4GRID, was recently funded by the Italian Minister of Economic Development, Italy. The project, which involves five Italian partners (companies, universities, and research institutes), is aimed to demonstrate the feasibility of cost-competitive SMES based on magnesium diboride (MgB2 ) with a cryogen-free cooling bymeans of the manufacturing and the testing of a demonstrator with an objective rating of 500 kJ/200 kW. This rating is deemed suitable for disclosing the critical technological aspects of all components in view of practical applications. A further goal of the project is the assessment of the technical and economic benefits that the SMES can bring to real-world electric grids. The general outline and technical objectives of the project are presented in this paper. Preliminary design assumptions and results concerning the MgB2 coil and the power condition system are also discussed. [ABSTRACT FROM AUTHOR]

A three-year research project, called DRYSMES 4GRID, was recently funded by the Italian Minister of Economic Development, Italy. The project, which involves five Italian partners (companies, universities, and research institutes), is aimed to demonstrate the feasibility of cost-competitive SMES based on magnesium diboride (MgB2 ) with a cryogen-free cooling bymeans of the manufacturing and the testing of a demonstrator with an objective rating of 500 kJ/200 kW. This rating is deemed suitable for disclosing the critical technological aspects of all components in view of practical applications. A further goal of the project is the assessment of the technical and economic benefits that the SMES can bring to real-world electric grids. The general outline and technical objectives of the project are presented in this paper. Preliminary design assumptions and results concerning the MgB2 coil and the power condition system are also discussed. [ABSTRACT FROM AUTHOR]