No abstract

No abstract

High resolution magnetic susceptibility imaging is a new technique for investigating the composition of diamagnetic and paramagnetic objects. It might contribute to the nondestructive evaluation of critical components by identifying both surface and internal defects. In order to demonstrate the technique, we have attached magnetizing coils to our high resolution MicroSQUID magnetometer. With our present system, we can apply a nearly uniform field of 0.3 mT, 2.0-2.5 mm below the 3 mm diameter sensing coils. By placing a sample in this applied field and scanning, MicroSQUID measures the local magnetic field variations caused by the spatial distribution of magnetic susceptibility in the sample. The system has sufficient sensitivity to image susceptibility-induced field changes equal to 3 x of the applied field, in a 100 Hz bandwidth. We describe the concept of susceptibility imaging and present preliminary data.

No abstract

No abstract