A Torsion Gradiometer Array: Differential Spin-Precession Sensing of Torsion Gradients with a Computed Noise Floor

A torsion gradient is the spatial rate of change of the torsion field, and in the Einstein-Cartan framework it is the quantity that a laboratory instrument can hope to register without waiting for astrophysical densities. This paper specifies an array of sixteen spin-ensemble pairs on a 0.40 m baseline that reads the gradient through differential spin precession. With a stated torsion-to-precession coupling efficiency of one per cent, the computed gradient noise floor is 5.50e-13 per square metre per root hertz, the response to a reference gradient of 1e-11 per square metre reaches a signal-to-noise ratio of five in 76 milliseconds, and the dynamic range extends to 4.17e-07 per square metre, a span of 7.58e+05. Common-mode rejection of uniform torsion and of magnetic disturbances is obtained by differencing within each pair and across the array. The design is complete to the level of a buildable specification. SIMULATED, NOT MEASURED: all performance figures are computed from the stated assumptions and no prototype has been operated.