高温超导量子干涉器在无损检测中的应用研究

Research on Non-Destructive Evaluation Based on High Tc SQUID

研制了一套可长时间稳定工作在无屏蔽环境中的高温超导量子干涉器(SQUID)无损检测装置,其中SQUID由Yba2Cu3O7(YBCO)制成.为了减小低频噪声,SQUID器件采用多圈条形结构,膜条宽度8μm,膜条间隔10μm,器件的有效面积为0.01mm2,在无屏蔽环境中的磁通白噪声约为200μΦ0/Hz.利用该装置对有内部缺陷的铝样品进行了电磁无损检测实验研究,并对激励频率与缺陷深度、缺陷大小与信号响应之间的关系进行了初步的探讨.

A non-destructive equipment based on high Tc DC Superconducting Quantum Interference Device (SQUID) is set up, in which the SQUID is fabricated by YBa-2Cu-3O-7(YBCO) thin film. This equipment can be operated stably in unshielded environment. In order to eliminate the low frequency interference, the SQUID washer is interpenetrated by nine slots, each 10 μm wide, separating ten YBCO strips, each 8 μm wide. The SQUID has an effective pick-up area of 0.01 mm^2 and a level of flux noise of 200μ%Φ%-0/Hz in unshielded environment. With this equipment, some electro-magnetic evaluation to aluminum samples with inner defects was performed and the relationship between the exciting frequency and defect depth, the size of defect and SQUID response are discussed.