We developed a cryocooled SQUID system with which human magnetocardiogram (MCG) and possibly magnetoenceparogram (MEG) can be measured. To reduce cyclic magnetic noises originating from the regenerator of the cold heads of the cryocooler, a superconductive shield (99.5% Pb) was used to protect the SQUID sensors, and a ferromagnetic shield (78% Ni alloy) was used to screen the cold head. In addition, the SQUID sensors' chamber was placed at a distance of 1.8 m from the cold head chamber to install the cold-head chamber outside the magnetically shielded room (MSR) for future development. The loss in cooling power due to the increased distance was compensated by increasing the number of thermal rods, and thus the SQUID sensor and superconductive shield could be refrigerated to 4.8 K and 5 K, respectively. The superconductive shield successfully rejected thermal noise emitted from metallic blocks used to improve thermal conduction. The noise of the SQUID system was 3 fT/Hz 1 2 , and the cyclic magnetic noise could be reduced to 1.7 pT. We could obtain a clear MCG signal while the entire cryogenics was in operation without any special digital processing.

Real-time pulse measurements of nano-scale field effect transistors (FETs) are reported. We demonstrate the direct monitoring of the real-time current of bottom-up assembled silicon nanowire FET and top-down fabricated gate-all-around silicon nanowire FET, both with the diameter of approximately 50 nm. We demonstrate that the displacement current can be cancelled out from the measured pulse responses. On the other hand, the displacement current also can be utilized to obtain the coupling capacitance between the gate and source of the FETs.