Abstract A non-destructive evaluation system based on high-Tc dc-SQUID (superconducting quantum interference device) incorporating a gradient field excitation has been built. By using this system a 1mm-diameter hole at a depth of 2mm inside an aluminium plate at room temperature can be easily detected and imaged in an unshielded environment. The relation between the spatial resolution, or the smallest detectable flaw size, and experimental parameters is briefly analysed in terms of a simple metal ring model. The result shows that the spatial resolution depends strongly on the sensor-sample separation as well as on some other parameters, such as signal-to-noise ratio of excitation, excitation frequency and material conductivity.
Received: 06 June 2003
Revised: 23 July 2003
Accepted manuscript online:
Fund: Project supported by the Foundation from the Ministry of Science and Technology of China, and the National Center for R & D on Superconductivity (Grant No NKBRSF-G19990646 and 2002AA306412).
Cite this article:
Wang Hui-Wu (王会武), Kong Xiang-Yan (孔祥燕), Ren Yu-Feng (任育峰), Yu Hong-Wei (于洪伟), Ding Hong-Sheng (丁红胜), Zhao Shi-Ping (赵士平), Chen Geng-Hua (陈赓华), Zhou Yue-Liang (周岳亮), Zhang Li-Hua (张利华), He Yu-Sheng (何豫生), Yang Qian-Sheng (杨乾声) Research on high-Tc SQUID based non-destructive evaluation 2004 Chinese Physics 13 19
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
