We have analyzed the possibility to construct multichannel magnetoencephalography (MEG) systems based on high-Tc direct current superconducting quantum interference devices (DC SQUIDs) with graphoepitaxial step edge Josephson junctions. A new layout of multilayer high-Tc superconducting flux transformers was tested and a new type of high-Tc DC SQUID magnetometer intended for MEG systems was realized. These magnetometers have a vacuum-tight capsule of outer diameter 24 mm and a magnetic field resolution of ∼ fT/Hz at 77 K. Crosstalk between adjacent sensors was estimated and measured for in-plane and axial configurations. The vibration-free cooling of sensors, minimization of the sensor-to-object distance and optimization of the sensor positions as well as the gantry design are discussed. Our findings may have implications for the next generation of non-invasive imaging techniques that will be used to understand human brain function.
- Josephson junctions