High frequency CMR-B-Scalar sensor for pulsed magnetic field measurement

Abstract

In order to decrease the influence of the “loop effect” on the signal measured by a recently developed CMR-B-scalar sensor, a compensation method was used. A B-dot sensor of the same geometry as the CMR-B-scalar sensor’s current leads was used for that purpose. This allows subtracting the time derivative of the magnetic field signal from the total measurement signal obtained by the CMR-B-scalar sensor. The B-dot sensor was placed at a distance of only 0.3 mm from the CMR-B-scalar sensor. The signal from the B-dot sensor was directly measured using an oscilloscope and subtracted from the signal of the CMRB- scalar sensor with an empirically determined weight factor. This allowed investigating the high-frequency behavior of the CMR-B-scalar sensor using an oscillating source of magnetic field with a time-derivative equal to 0.76 Tesla/microsecond. Performing the compensation described above it was possible to minimize the influence of the “loop effect” down to a level to be able to measure magnetic field pulses with amplitudes up to 5 T and rise times of 3.5 μs with an overall accuracy of about 10%.