YBCO
線材の
MO法による評価
低温工学協会 九州・西日本支部研究会 2006 July 20-22
Photograph of core part
Core part of RTR-MOI
MO
装置 開発
MO装置
開発
R1 R2 R3 R4 R5 R6
#1 20 6.5 10 0.13 - 2.5
#2 20 6.4 10 0.14 - 2.5
#3 20 6.7 10 0.12 - 2.5
#4 20 6.9 10 0.11 - 2.5
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QuickTime˛ Ç∆
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Low defect density ! A lot of defects !
MOI に用いる磁気光学膜の作製
The indicator films are necessary to observe MO images.
MO
装置 開発
MO装置
開発
We obtain high quality MO indicator films !
YBCO
線材の
MO法による評価
低温工学協会 九州・西日本支部研究会 2006 July 20-22
初期の IBAD/PLD 線材の磁束侵入の様子
IBAD/PLD
素線評価 素線評価
Defects
Fujikura #106880 40K ZFC
10mT 20mT 30mT 40mT 50mT 60mT
70mT 80mT 90mT 100mT Remanent
10mm
IBAD/PLD 線材への磁束侵入は左右均一
Dendritic な磁束侵入が µm オーダで折れ曲がっ
バッファ層の粒界の細かさを反映している ている
conductors in USA Flux penetration into
RABiTS tape
D. M. Feldmann (Polyanskii group) et al.Appl. Phys. Lett. 77 (2000)2906.
YBCO(PLD)/CeO2/YSZ/CeO2/Ni
15K 600 Oe
Grain boundaries are connected each other with small angles, and magnetic flux penetrates along grain boundaries.
Rolling aligned Ni has a large grain (~ 100µm).
YBCO
線材の
MO法による評価
低温工学協会 九州・西日本支部研究会 2006 July 20-22
RTR-MOI 装置による MO 観察結果
IBAD/PLD (Total length 1.5m) ZFC 40K 80 mT [NCCC]
This tape has only a few defects. Magnetic flux penetration is uniform for both width and length directions.
150 mm
I
c~250A
10 mm
素線評価 素線評価
Movie of the observation result by RTR-MOI Movie of the observation result by RTR-MOI
IBAD/PLD (Total length 1.5m) IBAD/PLD (Total length 1.5m)
ZFC 40K 50 mT ZFC 40K 50 mT [NCCC]
[NCCC]
I
c~250A I
c~250A
10 mm (width) 10 mm (width)
Tape edge Tape edge
Tape edge Tape edge
Shooting time ~ 1 hour
Shooting time ~ 1 hour
素線評価 素線評価
YBCO
線材の
MO法による評価
低温工学協会 九州・西日本支部研究会 2006 July 20-22
RTR-MOI
Hall sensor array (Tapestar@THEVA)
Both Hall sensor array equipment (tapestar@THEVA) and our new RTR- MOI can visualize 2D-image of flux distribution.
Using same sample : TFA-MOD (I
c~100A) [SRL, early stage specimen]
40K, 50mT
77K, 20mT
10 mm (width)
MOI has a higher spatial resolution !
There are many defects in this sample.
Hall sensors array can detect same defect.
1µm - 10µm
Spatial resolution of RTR-MOI equipment
素線評価 素線評価
1μμ 10μμ 100 μμ 1μμ 10μμ 100μμ
1μ 1μ 10μ 100μ
Comparison with other characterization methods Spatial resolution
Measuring speed(m/h)
RTR MOI
Hall sensor array system
RTR I-V meas.
V I
Hall sensor array(Tapestar@THEVA)
RTR I-V measurement
coated conductor
Field
Moving
We must choose measuring method by the purpose!
