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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Progress in Superconductivity and Cryogenics
Journal Basic Information
Journal DOI :
The Korea Institute of Applied Superconductivity and Cryogenics
Editor in Chief :
Volume & Issues
Volume 1, Issue 2 - Oct 1999
Volume 1, Issue 1 - May 1999
Selecting the target year
Y2BaCuO4 Segregarion , a Possibility of Multi-Seeding and the Origin of Diagonal Line in YBa2Cu3O7-
Superconductor Single Crystal
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 1~6
The microstructures of top seed mult processde
single crystal were studied. Although shape of the seed was not faceted. the growth shape of Y123 single crystal was faceted. It was observed that Y211 phases were trapped in specific spaces of the faceted region. From the microstructural investigation. it was suggested that the segregation of Y211 is due to the difference of growth rates in crystal direction. When a single crystal was grown by the single seed with stepped multi surfaces. a microstrue was grown from multi-seed. The microstructure show the possibility of multi-seed growth. Corn kernel like structure without Y211 phase was observed and seemed to be formed by the diffusion reaction between Y211 phase in crystal and liquid wetted on the crystal. the diagonal line on Y123 crystal was observed that it was formed by the corn kernel like structure.
Superconducting Films by the LiReac-PreCu Method
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 7~14
suppercondcting thick films were fabricared on copper tape by LiReac-PreCu (liquid reaction between a Cu-free precousor and Cu tape) method. Cu-free precursor power which is composed of
was printed on a copper tape by screen printing and was heat-treated. The speciment were partially in a molten state at the heat treatment temperature (85
). The heat heat treatments for the reaction were performed in air or low oxygen pressure in several stages. XRD analyses of the resulting Bi2Sr2CaCu2O8 superconducting tapes show that the
phase is dominant and a small amount of
phase is detected. Both phases are aligned in the c-axis direction
Effects of Precursor Powders on the Directional Growth of
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 15~21
superconductors samples were grown directionally using different precursors of
power. and a mixture of
powder. The microstructures and superconducting properties of the samples were compared. The mixture powder produced better microstructures i.e. dense and crack-free so that a higher critical current density was achieved at the same hot-zone temperature of 115
than the reacted powder does. When the reacted powder used as a precursor, as the hot-zone temperature increased upto 1215
, the texture of the sample improved and the critical current density increased. The amount of melt in the sample is of secondary importance for the growth of superconducting
grains. The microstructures and superconductivity of good quality superconductors grown directionally were more strongly influenced by the kind of precursor rather than the amount og melt in a sample.
Study on Current Capacity of the SC Conductor for
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 22~27
Recently, small-sized superconducting magnetic storage(
SMES) coils become commercially as an energy storage device for a power conditioner. In design and fabrication of the
SMES coils, to determine optimum current capacity of the superconducting(SC) conductors is one of the important things. We thus investigated the effect of conductor's current capacity, current density, and stability on the coil's maximum stored energy density in consideration of AC losses and switching device's capacities in a power converter. The results show that the smaller current capacity of the SC conductors is preferred for the
SMES coils but can increase their induced voltage excessively.
Simulation of a Resistive Superconducting Fault Current Limiter for Line Faults in the Power Grid
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 28~32
We have performed an EMTDC simulation for the current limiting effects of a superconducting fault current limiter (SFCL). The fault currents in the 154 kV transmission line between the arbitrary S1 and S2 substations increased up to 54 KA and 60 KA during the line-to-line and three phase faults, respectively. The SFCL with 100
of resistance after quench limited the currents to less than 17 KA within a half cycle. This limited current is well below the upper limit of a circuit breaker, suggesting that the resistance of the SFCL in the transmission line is sufficient.
Investigation on the Loop Current in the CICC Superconducting Magnet
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 33~37
The fast current and field ramp-up experiment was done with the superconducting magnet that is made of three non-insulated strand CICC (Cable-In- Conduit Conductor). The shunt the unbalanced current magnet enabled the unbalanced current measurement which is believed to be associated with the loop current. To explain the generation of the loop current during the current ramp up. the steady-state three strand loop current model was proposed. This model gives an explanation for the relation between the loop current and the twist geometry of the strands. According to this model. The twisr geometry and the surface contact resistance of the strand has significant influence on the generation of the loop current especially in the large superconducting magnet.
The Influence on self Field Losses in 2nd Stage Superconducting Cable for Different Twist Direction of Filaments
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 38~41
Strands composing multistage superconducting cables for AC power applications have twisted structure in each stage for lower AC loss and higher stability. So, when transport currents flow in a cable, each strand is exposed to longitudinal and azimuthal magnetic fields produced by transport current flowing in strand itself and Iongitudinal and transverse magnetic fields by transport current flowing in twisted cable. In this paper. we study the influence on self field lesses generated in second stage superconducting cable for different twist direction of filaments in a strand considering twist of strands in cables.
Two-Dimensional Analysis of Enthalpy Flow in a Pulse Tube
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 42~47
Enthalpy transport in a pulse tube was investigated by two-dimensional analysis of mass. momentum an energy equations of the gas as well as energy conservation of the tube wall. The mean temperature of the gas and the tube wall was obtained directly by assuming that the outer surface of a pules tibe wall is adiabatic. Axial profile of mean temperature is small. but it deviates significantly from linear profile when the dimensionless frequency is large. Effect of operating frequency. tube wall thickness, velocity ratio and velocity phase angle between both ends of a pulse tube on net enthalpy flow were shown.
Thermodynamic Analysis of Power Generation Cycle Utilizing LNG Cold Energy
Progress in Superconductivity and Cryogenics, volume 1, issue 1, 1999, Pages 48~55
thermodynamic cycle analysis has been performed for the power generation systems to utilize the cold energy of liquefied natural gas (LNG). The power cycle used the air or water at room temperature as a heat source and the LNG at cryogenic temperature as a heat sink. Among manypossible configurations of the cycle. the open Rankine cycle. and the closed Brayton cycle, and the closed Rankine cycle are selected for the basic analysis because of their practical importance. The power output per unit mass of LNG has been analytically calculated for various design parameters such as the pressure ratio. the mass flow rate. the adiabatic efficiency. the heat exchanger effectiveness. or the working fluid. The optimal conditions for the parameters are presented to maximize the power output and the design considerations are discussed. It is concluded that the open Rankine cycle is the most recormmendable both in thermodynamic efficency and in practice.