کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1818883 1525753 2010 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Degradation of the performance of a YBCO-coated conductor double pancake coil due to epoxy impregnation
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
Degradation of the performance of a YBCO-coated conductor double pancake coil due to epoxy impregnation
چکیده انگلیسی

Now that YBCO-coated conductors have been commercialized, a number of YBCO coils have been developed. However, their basic performances have not been systematically investigated so far. Here, we demonstrate that of a YBCO double pancake coil. The critical current of an epoxy impregnated YBCO double pancake coil was substantially degraded, i.e. the normal voltage appears above 8 A, only 18% of that for the dry coil. It was inferred that degradation occurs if the cumulative radial stress developed during cool down exceeds the critical transverse stress for the YBCO-coated conductor (typically 10 MPa). Under these conditions, the conductor was debonded at the interface between the buffer layer and YBCO layers, or fractured in the YBCO layer itself, causing cracks on the YBCO layer, resulting in a significant decline of the critical current. These negative effects are suppressed if the coils are dry wound or impregnated with paraffin, as the bonding strengths between turns are negligible and therefore turns are separated if the cumulative radial stress tends to be tensile. For non-circular coils in which epoxy impregnation is inevitable, degradation due to cumulative tensile transverse stress is still the major problem.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica C: Superconductivity - Volume 470, Issues 17–18, 1 September 2010, Pages 674–677
نویسندگان
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