A high Tc superconducting quantum interference device (SQUID) magnetometer utilizing a copper pickup coil cooled to T = 77 K and a resonant coupling circuit was developed. Using the resonant coupling circuit, we can greatly increase the signal flux transferred to the SQUID. Cooling of the pickup coil is useful for increasing the signal flux transferred to the SQUID and for decreasing the noise of the pickup coil. As a result, we obtained a magnetic field noise of 34.8 fT/Hz1/2 at a resonant frequency of 6.37 kHz when the pickup coil was mode of 200 μm-φ Cu wire with the number of turns n of 150 and radius of the coil r of 15 mm.
All Science Journal Classification (ASJC) codes
- General Engineering
- General Physics and Astronomy