Next Generation HTS SQUID Gradiometer Systems and their Portable Operation in Unshielded Environments

该计划旨在开发完全便携式和更灵敏的高温超导SQUID系统，该系统将在无屏蔽的环境中运行，并大大增加其在生物磁性测量（特别是成人和胎儿的心磁测量）中的应用潜力。通过（a）开发SQUID的改进版本-超导准干涉滤波器或SQIF（B）提高SQUID与其场感测线圈之间的耦合效率，包括开发基于NdBaCuO的多层结构和（c）开发在较大衬底上生长HTS膜以制造较大梯度计的技术来提高固有灵敏度。无屏蔽测量用高平衡二阶梯度仪的研制。这些将由两个一阶梯度仪形成电子，通过三轴参考磁力计和基于计算机的时域或频域处理来附加噪声抑制。通过设计、分析和测试一个不使用低温液体制冷机的原型系统，以固体氮制冷机为基础，提高了便携性。

This programme aims to develop fully-portable and more sensitive HTS SQUID systems that will operate in unshielded environr and to greatly increase their potential for use in biomagnetic measurements (in particular adult and foetal magnetocardiogra non-destructive evaluation and geophysics.There are three strands to the programme:1. Improvements to the intrinsic sensitivity by (a) developing a modified version of the SQUID - the Superconducting Qua Interference Filter or SQIF (b) enhancing the coupling efficiency between the SQUID and its field-sensing coils, includin development of multi-layer structures based on NdBaCuO and (c) developing techniques to grow HTS films on larger substrate to make larger gradiometers.2. The development of high-balanced second-order gradiometers for unshielded measurements. These will be formed electron from two first-order gradiometers, with additional noise rejection by 3-axis reference magnetometers and computer-based s processing in the time or frequency domains.3. Improvements to portability through the design, analysis and testing of a prototype system that uses no cryogenic liquid cryocooler, based on a solid nitrogen cooler.