Abstract: We have investigated the stability of 2.0 GJ toroidal HTS-SMES, which consists of 90 element coils wound from YBCO tape. If one or more element coils are quenched, the storage energy reduces due to change of the magnetic field distribution. A series of quench for some element coils may occur, when the energy of the quenched coil cannot be consumed adequately. The simultaneous quench of some element coil may cause the system down. Therefore, it is necessary to investigate the simultaneous quench properties.
Abstract: In this work we present a solution for testing the quality of YBCO rings made from bulk and 100% YBCO wire loops. We used the transformation of the DC magnetic field . Nowadays there are more and more solutions for checking the quality . In this article we show a new method for testing applying the transformation of the DC magnetic field between two independent iron cores inductively.
Abstract: The critical current density, jc, of high-pressure synthesized MgB2-based balk materials correlates with the amount and distribution of higher borides (MgB12) and Mg-B-O inclusions, which in tern correlates with the synthesis temperature and presence of additions (Ti, Ta, SiC). High-pressure-synthesized materials with near MgB12 composition of matrix exhibited superconducting transition temperature, Tc, of about 37 K, rather high jc (5∙105 and 103 A/cm2 in 0 T and 3.5 T, respectively, at 20 K) and doubled matrix microhardness: 25±1.1 GPa at 4.9 N –load as compared to materials with MgB2).
Abstract: New model of the capturing vortices in the HTc superconductors is presented, describing their electromagnetic properties, such as the critical current of these materials. Critical current of the superconductors, such as HTc tapes is dependent on the magnitude of the interaction magnetic vortices with pinning centers. This is in fact quantum effect since the magnetic flux in vortices is quantized. Capturing the vortices on the normal state nano-sized inclusions should lead to the modification of the flux distribution in the vortex core depending on the vortex position in the respect to the pinning center edge. These effects are considered in the paper and their influence on the critical current of the HTc materials, basing on the new model of the pinning interaction.
Abstract: The knowledge of the current-phase relation (CPR) in superconducting junctions is essential in many applications like low-dissipative superconducting electronics or superconducting qubits for quantum computation. Theory predicts that unconventional superconductivity induces a significant second harmonic J2 in the CPR. Consequently, anomalies such as half-integer Shapiro steps should be observed in the microwave assisted current-voltage characteristics of the junctions. We performed electric transport measurements in YBa2Cu3O7-x/Nb unconventional superconductor junctions for 72 different tunneling directions in the ab plane and found no trace of such anomalies. This suggest that J2 is insignificantly small so that YBa2Cu3O7-x/Nb junctions have a purely sinusoidal CPR.
Abstract: This paper presents the design of a novel superconducting levitated module for UAQ4 train whose feasibility has been successfully tested and confirmed in laboratory. The work concept of self-balancing “V” shaped levitation module is described and the results of levitation tests performed using a measurement set up are discussed. Lastly the levitation module performances are also carried out using numerical finite element analyses by varying the sideslip angle of the module and work system configuration.
Abstract: The national project of the development technology of next generation applied electromagnetic machinery was founded in Oita as Oita Prefecture Innovative JST (Japan Science and Technology Agency) Research Program. In this paper, outline of this project is introduced and the basic technology which is based on vector magnetic property is described. Especially the vector magnetic properties in high flux density level of 1.9 T are shown. As the example results, the dynamic vector magnetic characteristic is applied to the surface permanent magnet motor.
Abstract: A new simple two-dimensional local magnetic property measurement system is presented. In this paper, we developed a new transducer whose two amorphous cores enables measure in a high magnetic induction range. Experimental results show very good agreements with ones of conventional 2-D measurement system.