AC Losses in Striated YBCO Coated Conductors

Abstract

We measured AC losses in RABiTS nonstriated as well as striated coated conductors provided by the US Air Force Research Laboratory. In addition, samples with different kinds of well defined inter-filament bridging have been measured and their losses compared with those of samples with unbridged filaments and with mono-layer samples. This bridging is designed to aid current sharing between filaments, which is advantageous, but it is necessary to determine if the effect on AC losses is detrimental. It was found that AC losses of striated samples with multiple bridges are higher than those of the samples with no bridges due to significant filament coupling but even so the losses are still substantially lower than those of a monolayer sample.

The comparative study of magnetic properties for YBCO coated conductors based on RABiTS and IBAD templates

“…Drastic improvements in the length and the current carrying capability of HTS-CC have been accomplished for last several years [2][3][4][5][6][7]. The issues in this field is shifting to securing uniformity and reproducibility of the manufacturing processes, improving flux pinning properties (in-field current carrying properties) [8][9][10][11][12][13] and reducing ac (alternate current) losses [14][15][16][17]. When the HTS-CC is used for ac applications, however, the ac-loss of the conductor becomes as important a factor as the high transport current in a high magnetic field.…”

Thin YBa2Cu3O7-δpatterns by Chemical Solution Processing using Ink-Jet Printing

“…This is important because it is reported in the literature that the hysteresis losses will be decreased by the inverse of the number of lines (1/N a ) in comparison with a completely covered substrate [15,22]. The currently reported width for patterns is going from 30 µm up to one millimeter when using lithography or etching methods [7,8,12,11,16,19,21,22,24]. With our ink-jet printing technique we can obtain a similar lateral resolution in only one processing step.…”

“…These conductors can be wound as coils and, when used in motors and generators instead of copper wires, they can reduce the total size and weight of the device because of their ability to carry high currents without resistance. Yet, these coated conductors produce large losses when used with alternating current (AC) or fields [6][7][8][9]. The high aspect ratio of the coated conductor geometry leads to high hysteresis losses proportional to the width of the superconducting film.…”

“…This filamentary superconducting structure can be accomplished through several techniques which can be divided into two main approaches: with or without material removal. Lithography, wet chemical etching, ion beam etching, laser ablation or slitting of the tape are techniques where superconducting material is removed [7,8,12,[19][20][21]. They have a variety of disadvantages such as high cost, local degradation of the superconducting properties or tape fragmentation.…”

The Integration of YBACU3O6+X Coated Conductors into Magnets and Rotating Machinery

“…The main route to hysteresis (and overall) loss reduction that has been explored in recent years is the replacement of the uniform wide YBCO film with a set of parallel narrow filaments (stripes) [2][3][4][5][6][7][8]. The first experiments have demonstrated that the hysteresis loss in experimental multifilamentary samples can be reduced by at least an order of magnitude.…”