Imaging of small defects in nonmagnetic tubing using a SQUID magnetometer
Source abstract
Abstract
Abstract Using a recently developed superconducting quantum interference device (SQUID) magnetometer system which offers higher resolution and greater sensitivity than previous designs, we have created high-resolution spatial maps of the magnetic anomalies created by small defects in thin-walled, nonmagnetic tubes. Images obtained using three different sensing methods (injected current, induced current, and ferromagnetic decoration) are presented, and compared in terms of sensitivity and signal-to-noise ratio (SNR). All three methods possess the sensitivity to detect holes on a tube's outer diameter as small as 0.37 mm diameter × 0.54 mm deep, with varying SNR, as well as holes on the tube's inner diameter as small as 1.0 mm diameter × 0.3 mm deep. The ferromagnetic decoration method produces the strongest signals and excellent SNRs. Using this approach, we have detected inner- and outer-diameter slots with dimensions 0.76 × 0.15 × 0.08 mm3. In addition, we examine results of numerical inversion calculations applied to the experimental images. With inversion techniques it is possible to determine the original current density distribution given the measured magnetic field, hence revealing the approximate shape and location of defects.
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Research context
OpenAlex topics: Non-Destructive Testing Techniques · Geophysical and Geoelectrical Methods · Physics of Superconductivity and Magnetism
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References (24)
Show source-provided references
1. J. Clarke.Proc. IEEE 771208 (1989)10.1109/5.34120 ↗
2. J. Clarke. InSuperconducting Electronics edited by H. Weinstock and M. Nisenoff, NATO ASI Series, Vol. F59, pp. 87–148. Springer-Verlag, Berlin (1989)10.1007/978-3-642-83885-9_5 ↗
3. G.L. Romani. InSuperconducting Electronics op. cit., pp. 149–17410.1007/978-3-642-83885-9_6 ↗
4. G.B. Donaldson. InSuperconducting Electronics op. cit., pp. 175–20710.1007/978-3-642-83885-9_7 ↗
5. M. Odegnal.Sov. J. Low Temp. Phys. 111 (1985)
6. H. Weinstock.IEEE Trans. Magn. 273231 (1991)10.1109/20.133898 ↗
7. R.J.P. Bain, G.B. Donaldson, S. Evanson, and G. Hayward. InSQUID '85 edited by H.D. Hahlbohm and H. Lubbig, pp. 841–846. de Gruyter, Berlin (1985)
8. R.J.P. Bain, G.B. Donaldson, S. Evanson, and G. Hayward.IEEE Trans. Magn. 23473 (1987)10.1109/TMAG.1987.1065036 ↗
9. H. Weinstock and M. Nisenoff. InReview of Progress in Quantitative Nondestructive Evaluation, 5A edited by D.O. Thompson and D.E. Chimenti, pp. 699–704. Plenum, New York (1986)10.1007/978-1-4615-7763-8_72 ↗
10. H. Weinstock and M. Nisenoff. InSQUID '85 edited by H.D. Hahlbohm and H. Lubbig, pp. 853–858. de Gruyter, Berlin (1985)
11. Y.P. Ma, D.J. Staton, N.G. Sepulveda, and J.P. Wikswo, Jr. InReview of Progress in Quantitative Nondestructive Evaluation, 10A edited by D.O. Thompson and D.E. Chimenti, pp. 979–986. Plenum, New York (1991)
12. D.J. Staton, Y.P. Ma, N.G. Sepulveda, and J.P. Wikswo, Jr.IEEE Trans. Magn. 273237 (1991)10.1109/20.133901 ↗
13. Y.P. Ma and J.P. Wikswo, Jr. InReview of Progress in Quantiative Nondestructive Evaluation, 11A, edited by D.O. Thompson and D.E. Chimenti, pp. 1153–1159
14. J.P. Wikswo, Jr., J. van Egeraat, Y.P. Ma, N.G. Sepulveda, D.J. Staton, S. Tan, and R.S. Wijesinghe. InDigital Image Synthesis and Inverse Optics edited by A.F. Gmitro, P.S. Idell, and I.J. LaHaie, SPIE Proceedings, Vol. 1351, p. 438. Society of Photo-Optical Instrumentation Engineering, Bellingham, WA (1990)10.1117/12.23656 ↗
15. D.S. Buchanan, D.B. Crum, D. Cox and J.P. Wikswo, Jr. InAdvances in Biomagnetism, edited by S.J. Williamson, M. Hoke, G. Stroink, and M. Kotani, pp. 677–679
16. Y.P. Ma and J.P. Wikswo, Jr.Rev. Sci. Inst. 622654 (1991)10.1063/1.1142195 ↗
17. J.P. Wikswo, Jr., D.B. Crum, W.P. Henry, Y.P. Ma, M.G. Sepulveda, and D.J. Staton.J. Nondest. Eval. (in press)
18. N.G. Sepulveda, D.J. Staton, and J.P. Wikswo, Jr. J. Nondest. Eval.1189 (1992)10.1007/BF00568292 ↗
19. Y.P. Ma and J.P. Wikswo, Jr. InReview of Progress in Quantitative Nondestructive Evaluation, 12, edited by D.O. Thompson and D.E. Chimenti. Plenum, New York (in press)
20. W.N. Podney and P.V. Czipott.IEEE Trans. Magn. 273241 (1991)10.1109/20.133902 ↗
21. We used product #9C-M from Magnaflux (Chicago, IL) which consists of an iron oxide-based ferromagnetic powder in an oil-based aerosol.
22. S. Tan. Linear system imaging and its applications to magnetic measurements by SQUID magnetometers. PhD Thesis, Vanderbilt University (1992)
23. S. Tan, Y.P. Ma, I.M. Thomas, and J.P. Wikswo, Jr.IEEE Trans. Magn. (Proceedings of the Applied Superconductivity Conference) (in press)
24. A.A. Ioannides, J.P.R. Bolton, and C.J.S. Clarke.Inverse Problems 61 (1991)