Novel HTS DC Squid Solutions for NMR Applications
We have developed a multilayer flux-transformer-based high-TC SQUID (flip-chip) magnetometer that improves signal-to-noise-ratios (SNR) in ultra-low field magnetic resonance (ulf-MR) recordings of protons in water. Direct ulf-MR-based benchmarking of the flip-chip versus a standard planar high-TC SQUID magnetometer resulted in improvement of the SNR by a factor of 2. This gain is attributable to the improved transformation coefficient (1.9 vs 5.3 nT/Φ0) that increased the signal available to the flip-chip sensor and to the lower noise at the measurement frequency (15 vs 25 fT/Hz1/2 at 4 kHz). The improved SNR can lead to better spectroscopic resolution, lower imaging times, and higher resolution in ulf-MR imaging systems based on high-TC SQUID technology. The experimental details of the sensors, calibration, and ulf-MR benchmarking are presented in this report.
- 5.Öisjöen F (2011) High-TC SQUIDs for biomedical applications: immunoassays, MEG, and ULF-MRI. PhD dissertation, Chalmers University of Technology, Göteborg, unpublishedGoogle Scholar
- 6.Jönsson M (2011) Ultra-low field nuclear magnetic resonance using high-TC SQUIDs. Master’s thesis, Chalmers University of Technology, Göteborg, unpublishedGoogle Scholar