Fabrication of a three-dimensional vacuum magnetic sensor with a Si tip

A new vacuum magnetic sensor (VMS) device suitable for three-dimensional detection of magnetic flux was fabricated. This device consists of a Si field emitter tip that generates a cross-shaped electron beam and an anode that is divided into eight symmetrically arranged sectors. The cross-shaped electron beam is rotated and displaced from an initial position by the magnetic flux in accordance with the Lorentz force interaction. The rotation angle and the translational displacement were measured from the beam current imbalance between two neighboring anode sectors. Detection sensitivities of 10 4 %/ T and 10 3 %/ T were obtained for magnetic flux applied parallel and perpendicular to the VMS device, respectively.