Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 8

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  84.71.Mn
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Relation between Current Transfer Length and Stability of Fe/MgB_2 and Fe/Nb/MgB_2 Conductors

100%
Holúbek T., Kováč P., Hušek I.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
367-370
EN
This paper treats and confronts the stability of two different composite MgB_2 superconductors and searches for relation between the current transfer length and maximum heat flux that conductor can withstand in operational DC regime. It was found that the iron sheathed wire behave more stably than tape-like conductor with outer iron sheath and inner niobium barrier.
2
Content available remote

Pinning Force in Superconducting Wires Nb-Ti

100%
Gajda D., Zaleski A., Dyakonov V., Matrosov N., Szymczak H., Beloshenko V., Spuskanyuk V., Chishko V.
Acta Physica Polonica A
|
2010
|
vol. 118
|
issue 2
364-365
EN
In the paper we present the results of the measurements of critical current I_{c} in NbTi wires. Experiments were made for the wires of 0.3 mm in diameter and the length of 25 mm. The wires were produced by means of two methods: conventional (hydroextrusion and drawing) and preliminary equal channel multiple angle pressing. The samples were heat treated at different temperatures. We describe the influence of different pinning centers on critical current density J_{c}.
3
Publication available in full text mode
Content available

Superconducting and Microstructural Properties of (Mg+2B)+MgB_2/Cu Wires Obtained by High Gas Pressure Technology

100%
Kario A., Morawski A., Głowacki B., Łada T., Smaga M., Diduszko R., Kolesnikov D., Zaleski A., Kondrat A., Gajda D.
Acta Physica Polonica A
|
2007
|
vol. 111
|
issue 5
693-703
EN
In order to improve the overall critical current characteristics of Cu sheathed in situ MgB_2 wires a special architecture of the wire, and processing parameters were used. The study presents the influence of the ex situ MgB_2 chemical barrier between ex situ core and Cu, suppressing the reaction of Cu with Mg. Wires, doped with 10 at.% SiC of 18 nm average grain size, were fabricated from MgH_2 and B or from Mg and B powders, using the powder-in-tube method. The methods of rotary swaging or drawing were used as the alternating wire-forming processes. The samples were annealed under high Ar gas pressure (hot isostatic pressing) at 750ºC and 1.0 GPa for 15 and 30 min. A significant difference in Cu distribution across the wires for a long and short time of sintering was observed. The formation of microstructure in the powder-in-tube process and the relationship between the microstructure and critical current density J_c values, are discussed in this paper.
4
Content available remote

AC Susceptibility of the YBa_2Cu_3O_7 Coated Conductor in High Magnetic Fields

100%
Seiler E., Frolek L.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
379-382
EN
The AC susceptibility of the YBa_2Cu_3O_7 coated conductor in the perpendicular applied AC magnetic field was investigated using an inductive experimental setup with a pair of coils connected in opposite. A harmonic homogeneous AC magnetic field was applied perpendicularly to the wide face of the YBa_2Cu_3O_7 coated tape. Together with this AC field, a parallel background DC magnetic field up to 14 T was applied perpendicularly to the tape. The measurements were performed at several constant temperatures in the range 3-50 K. In the region of high background DC fields (8-14 T) no influence of the tape's ferromagnetic substrate was detected, despite of the low measurement temperatures employed. The estimate of the critical current density (j_c) at 20 K and 14 T, based on the position of the imaginary AC susceptibility peak, gives the value j_c=0.53 MA/cm^2.
5
Content available remote

DC Characterization of the Coaxial Superconducting Cable

51%
Šouc J., Gömöry F., Vojenčiak M., Frolek L., Isfort D., Ehrenberg J., Bock J.
Acta Physica Polonica A
|
2008
|
vol. 113
|
issue 1
375-378
EN
Coaxial cable model with superconducting core and superconducting shield conductor was constructed and tested in DC regime. While the core was already examined in our previous works, in this contribution the detailed study of the superconducting shield conductor in DC conditions is presented. It consists of 16 ReBCO coated tapes with critical current 35 A each connected in parallel. Using shunts with known values placed in series the currents in individual tapes were possible to measure. Distribution of the total cable current into the individual tapes was monitored and its influence on critical current of the cable is discussed.
6
Content available remote

Effects of Magnetic History on AC Loss Minimum in BSCCO-2223 Composite Tape

51%
Maievskyi E., Ciszek M., Trojanowski S.
Acta Physica Polonica A
|
2016
|
vol. 130
|
issue 2
527-530
EN
In the paper we report experimental results of AC magnetization losses in a multi-filamentary BSCCO-2223 superconducting composite tape due to coaxial AC and DC magnetic fields subjected perpendicularly to the plane of the tape. Such superposition of magnetic fields usually leads to some reduction of magnetization losses. A distinguished minimum in the AC loss is observed, at a certain DC bias magnetic field and at a certain fixed magnetic field amplitude. It is shown that the minimum of the AC losses very strongly depends on magnetic history of the investigated tape, which is directly related to the magnetic flux trapping within tape's superconducting filaments region. Measurements were carried out with a sinusoidally varying magnetic fields at amplitudes up to 100 mT and a superimposed DC magnetic field up to 50 mT, at frequency range of 21-113 Hz.
7
Content available remote

Fabrication and Transport Critical Current Densities of MgB_2/Fe/Cu Multifilament Tapes without Any Intermediate Annealing

45%
Yucel E., Terzioglu C., Varilci A., Gencer A., Belenli I.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 3
660-665
EN
We have fabricated superconducting 6 and 7 filaments MgB_2/Fe/Cu tapes by ex situ powder-in-tube method using Cu-sheath without any intermediate annealing. Properties of two different multicore MgB_2/Fe/Cu tapes annealed at 900C for 2 h in high purity argon gas atmosphere were compared. The samples were characterized using scanning electron microscope, X-ray diffraction, electron dispersive spectroscopy, optical microscopy, critical transition temperature, transport critical current density, and magnetic measurements. Transport critical current densities of the 6 and 7 filaments tapes were found to be 450 A/cm^2 and 190 A/cm^2 at 20 K, respectively. From X-ray diffraction measurements, lattice parameters a and c were determined. From dc resistivity measurements, the connectivity between grains was investigated by using Rowell's connectivity analysis.
8
Content available remote

Superconducting Devices for Power Engineering

32%
Janowski T., Kondratowicz-Kucewicz B., Wojtasiewicz G., Kozak S., Kozak J., Majka M., Jaroszyński L.
Acta Physica Polonica A
|
2016
|
vol. 130
|
issue 2
537-544
EN
The paper presents the current state of research on superconducting devices for the electrical power system, i.e. transformers, fault-current limiters, and energy storages. In particular, it describes scientific achievements of the Laboratory of Superconducting Technologies of Electrotechnical Institute. The development of distributed and renewable energy sources, as well as the increasing number of receivers with low power factor will rise interest in superconducting fault-current limiters and superconducting transformers rated below 1 MVA. Previous studies were focused on the largest power transformers and highest current superconducting fault-current limiters. ReBCO coated conductors allow to build efficient superconducting AC devices. Superconducting tape of a layered structure (second generation HTS tape) enables the construction of transformer rated up to a few MVA without the usage of parallel conductors. Relatively high resistance of the tape in normal state allows to build fault-current limiters and fault-current limiting transformers. Superconducting transformers and superconducting fault-current limiters can help to increase connected power of distribution stations and thereby accelerate development of renewable energy sources.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.