大有效面积的高T_c rf SQUID

Large effective area high T_c rf SQUID

设计和制作了一种新型结构的高TcrfSQUID探头 .在使用高温超导薄膜共面谐振器作为射频谐振回路的情况下 ,采用了大面积高温超导薄膜作磁聚焦器 .这种结构既有利于得到低的磁通白噪声 ,又可加上大面积聚焦器以增大有效面积 ,因而容易得到高的磁场灵敏度 .实验中在 1 5mm× 1 5mm的衬底上得到了有效面积为 1 2 7mm2 ,在磁通噪声为 2 1× 1 0 -50 Hz时 ,磁场灵敏度为 34fT Hz.

We have designed and fabricated a new type of high T-c if SQUID sensor. A high T-c coplanar superconducting resonator and a large area high T-c superconducting film concentrator have been used simultaneously. With a large effective area and low white flux noise, we have achieved a flux noise of 2.1 x 10(-5) phi(0)/ rootHz and a magnetic field sensitivity of 34fT/ rootHz in white noise range, respectively, using an effective area of 1.27 mm(2) concentrator on a 15 mm x 15 mm substrate. This design can be easily applied to higher frequency high T-c rf SQUID system.