TY - JOUR
T1 - Detection of deep flaws by using a HTS-SQUID in unshielded environment
AU - Jeng, J. T.
AU - Yang, S. Y.
AU - Horng, H. E.
AU - Yang, H. C.
N1 - Funding Information:
Manuscript reccivcd August 3, 2000. This work was supported by the National Sciencc Council of R.O.C. under Grant No. NSC-89-2112-M-003-012, and NSC-89-2112-M-002-029. J. T. Jeng is with the Physics Departmcnt, National Taiwan Normal Ilniversity, Taipei 116, Taiwan (e-inail: s41321~cc.ntnu.edu.t~) S.Y . Yang is with thc Institute ofl'hysics, Academia Sinica, Taipei 115, Taiwan (e-mail: eniesdolb~ms28.liinet.tiet) 11. E. Morng is with the Physics Dcpartmcnt, National Taiwan Normal University, Taipci 1 16, Taiwan (e-mail: [email protected]) H. C. Yang is with the Physics Department, National Taiwan University, Taipei 106, Taiwan (c-mail: [email protected])
PY - 2001/3
Y1 - 2001/3
N2 - We reported the nondestructive evaluation of flaws in conductive samples with the high-Tc SQUID operated at 77 K. By nulling the SQUID with an additional compensation, we can sensitively detect the excited magnetic field due to the eddy current around a deep flaw. To investigate the effects of the size and the depth of flaws on the induced magnetic field, the excited magnetic fields as a function of the depth were measured for buried slots with various widths and thickness. Besides, the amplitude and the phase with different excitation frequencies for a fixed slot size are also studied. It was found that for a fixed excitation frequency, the phase of the measured signal linearly responds to the depth of the slot, while the amplitude correlates with the height of the slot. The results are valuable for quantitative evaluation of flaws.
AB - We reported the nondestructive evaluation of flaws in conductive samples with the high-Tc SQUID operated at 77 K. By nulling the SQUID with an additional compensation, we can sensitively detect the excited magnetic field due to the eddy current around a deep flaw. To investigate the effects of the size and the depth of flaws on the induced magnetic field, the excited magnetic fields as a function of the depth were measured for buried slots with various widths and thickness. Besides, the amplitude and the phase with different excitation frequencies for a fixed slot size are also studied. It was found that for a fixed excitation frequency, the phase of the measured signal linearly responds to the depth of the slot, while the amplitude correlates with the height of the slot. The results are valuable for quantitative evaluation of flaws.
KW - Depth
KW - HTS-SQUID
KW - Nondestructive evaluation
KW - Phase
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U2 - 10.1109/77.919587
DO - 10.1109/77.919587
M3 - Conference article
AN - SCOPUS:0035268113
SN - 1051-8223
VL - 11
SP - 1295
EP - 1298
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 1 I
T2 - 2000 Applied Superconductivity Conference
Y2 - 17 September 2000 through 22 September 2000
ER -