Rotary Motion Faraday Cage
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
An improved Faraday cage structure is proposed in which rotary motion is used to move the cage between a first position at which the cage intercepts an electron beam and a second position at which the cage and its fields do not affect the electron beam. To measure the current of an electron beam, the beam must be interrupted by a collection device, such as a Faraday cage. Since the electron beam is located in a high vacuum, a measurement device, such as a Faraday cage, is difficult to accurately position mechanically. Complex designs do not allow the use of good vacuum-sealing techniques. In the illustrated design, a rotary motion is used to position a Faraday cage under the beam. This eliminates problems associated with linear motion vacuum seals and with mechanical positioning of the cage with respect to the beam.