IMPROVED THREE-AXIS SUPERCONDUCTING GRAVITY GRADIOMETER

摘要

Common mode (82) and differential mode (84) sensing coils are arranged adjacent a bottom-side surface of a portion of the proof mass (60) in one hollowed out annular portion (70) and a levitation coil (86) is arranged adjacent a bottom-side surface of the proof mass in the other hollowed out annular portion (72). The common mode (82), differential mode (84) and levitation (86) coils are connected in respective first, second and third superconducting circuits. The first circuit produces common mode signals indicative of forces acting on both accelerometers in the same direction. The second circuit produces differential mode circuits indicative of forces acting in different directions. The third circuit produces a force on each proof mass by which the proof masses are levitated. In addition, a superconducting negative spring coil (90) is wound on the periphery of the coil form.