Design of Electrostatic Feedback for an Experiment to Measure G
The torsion pendulum at the heart of the apparatus to measure the gravitational constant, $G$ at the Bureau International des Poids et Mesures (BIPM) is used to measure the gravitational torque between source and test-mass assemblies with two methods.In the Cavendish method, the pendulum moves freely.In the electrostatic-servo method, the pendulum