非磁性液体を用いた勾配磁場センサ  [in Japanese] Magnetic Field Gradient Sensor Using Liquids  [in Japanese]

A method was investigated for measuring the value of B・dB/dx, which determaines the magnetic force exerted on paramagnetic or dimagnetic substances. For this purpose, the change in the surface shape of fluids under inhomogeneous fields due to a phenomenon called the Moses effect, was used. When the space between two electrodes is filled with an electric conductive cross-section of the solution changes. As a result, the resistance between the electrodes also changes. The surface slope angle of an MnCl_2 solution was estimated for a wide range of B・dB/dx values, and the relationship between the B・dB/dx values and the resistance was calculated. Experimentally, we observed the resistance change expected according to the calculation. A system using two non-miscible liquids with different conductivities was also proposed for the detection of lower field gradients.