A superconducting strain transducer

Abstract

We have developed a prototype of a novel strain transducer. The change in magnetic reluctance in a ferromagnetic thorus with a gap due to the applied strain is detected by a superconducting magnetometer (SQUID). Strains as small as Δl/l=10⁻¹⁰ have been detected on a bandwidth of 1 Hz up to 16.7 kHz in a reduced sensitivity version of the apparatus. Further experimentation at higher sensitivity with the present experimental setup is prevented by the background mechanical noise of the building.