Top-seeded melt-growth (TSMG) processing of large bulk Y–Ba–Cu–O monodomains was advanced by applying Gd–Ba–Cu–O elongated seeds. The seeds, up to 38 mm in length, were fabricated by cutting Gd–Ba–Cu–O monodomains produced by the TSMG technique. Three types of seeds, differing in their orientation of crystallographic directions, were prepared. Crystal growth of the Y–Ba–Cu–O monodomain depending on crystallographic directions in the seed contact surface was investigated. It was established that every type of seed generates a different growth mode of the initial facet plane. It is shown that elongated seeds make for growth of a dominant crystal without spontaneous nucleation, decrease of processing time, reduction of maximum heating temperature and improvement of manufacturability and reproducibility of the TSMG process. Y–Ba–Cu–O monodomains up to 48 mm in diameter were produced using elongated seeds. They are able to trap magnetic fields up to 1.38 T.

We describe a new sample of 226 GPS (GHz-Peaked Spectrum) source candidates selected using simultaneous 1-22 GHz multi-frequency observations with the RATAN-600 radio telescope. Sixty objects in our sample are identified as GPS source candidates for the first time. The candidates were selected on the basis of their broad-band radio spectra only. We discuss the spectral and variability properties of selected objects of different optical classes.

Abstract. A magnetic filed relaxation at the center of a pulse-magnetized single-domain Y-Ba Introduction.Textured high-temperature superconductors (HTS) of Re(Y)-Ba-Cu-O family appear to be very promising materials for manufacturing superconducting magnets with very large magnitudes of trapped magnetic fields [1,2]. For example, trapping a field as high as 17 T between two 26.5-mm diameter Y-Ba-Cu-O disks at 29K has been demonstrated recently [3]. A comprehensive review of synthesis, characteristics and applications of high-quality HTS suitable for applications in superconducting magnets can be found in [4]. Recently significant research efforts have been directed towards using a pulse magnetization of HTS instead of an isothermal one [5]. An obvious advantage of the pulse magnetization with a typical pulse duration in order of 1 to 100 msec is a smaller amount of energy needed to create a magnetic field of a desired magnitude. There is, however, a complication that needs to be considered when using this method: an electromagnetic heating of a superconductor during the pulse magnetization plays much bigger role than during a slow magnetization because there is not enough time for the temperature to reach an equilibrium distribution within the superconducting volume. For example, a thermal time constant of a HTS sample at 78K with characteristic dimensions in order of 10 mm would be in order of a few seconds, which is much large than the pulse duration. This circumstance allows one to analyze the pulse magnetization as an adiabatic process. A negative effect of the heating during a single-pulse magnetization can be reduced by using a multi-pulse method. Using a combination of the multi-pulse magnetization and a step-by-step temperature decrease has been shown to allow trapping magnetic fields as high as 4.5T at 30K [6].One of the key performance characteristics of any magnet is a long-term stability of its magnetic field. Here superconducting magnets have a fundamental limitation due to a phenomenon known as a thermally-activated magnetic flux creep. According to Kim-Andersen theory a thermally-activated magnetic flux creep in type II superconductors [7], supercurrents and magnetization decrease logarithmically in time as

The Russian Federation is located at the crossroads of the trade routes of the Eurasian continent, where a significant volume of the transport flow of the world’s trade is formed. The transport potential of the territory of Russia, when implemented as an Integral Transit Transport System (ITTS), is comparable to the benefits from the traditional export of hydrocarbons and other raw materials. Analyzing the efficiency of transport systems, the key is the energy approach. The concept of ITTS is considered, based on all known and being developed transport lines, including high-speed vacuum magnetic levitation transport (VMLT). The fundamental problems are discussed being on the way to achieving the maximal speed, energy efficiency and throughput of VMLT. The preliminary findings are presented obtained from experiments on the test model of the VMLT route. It is concluded that there is a need for a deeper study of the properties of magnetic and superconducting materials in extreme high fields, power and speed regimes to search for fundamentally new technical solutions for the creation of VMLT

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