Using high-Tc SQUIDs, we have designed a nondestructive evaluation system to probe buried flaws. The frequency of the excitation magnetic fields was varied from 10 to 800 Hz and the magnetic fields generated from the eddy current was lock-in detected. The SQUIDs output data revealed the most effective excitation frequencies for the flaws with different depths and widths. The signal-to-noise ratio of the deep flaws can be further enhanced either by using higher excitation fields or using the SQUIDs with higher low-frequency sensitivity.
|頁（從 - 到）||2637-2638|
|期刊||Physica C: Superconductivity and its applications|
|出版狀態||已發佈 - 2000 十一月|
|事件||International Conference on Materials and Mechanisms of Superconductivity High Temperature Superconductors VI - Houston, TX, USA|
持續時間: 2000 二月 20 → 2000 二月 25
ASJC Scopus subject areas