A novel and cost-effective optical detection of high magnitude current and magnetic pulses through a metallic cantilever

Abstract

We report a novel optical technique to measure short duration high magnitude current and magnetic pulses based on deflection of a macroscopic ferromagnetic cantilever. Deflection of the cantilever as a transducer takes place due to the attraction by an electromagnet. The reflected laser beam from a small thin mirror at tip of the cantilever is scanned over two spatially distinct photodetectors. Different high magnitude magnetic pulses are produced by discharging a capacitor bank through an inductive coil with a ferrite core. The response of the sensor is observed at different charging limits of the capacitor bank and spatial intervals between cantilever and inductive coil. A repeatable and linear response is detected by the devised sensors in the range 158.53–380.47 A current and 0.19–0.48 T magnetic field with sensitivity of 39.15 A kV−1 and 50.98 mT kV−1 for current and magnetic field amplitudes respectively in response to 2.5–6.0 kV charging of the capacitor bank. The proposed technique is remote, nondestructive, cost-effective and has a large dynamic range.