Compact all-metal high-vacuum gate valve for microwave tube research

A manually operated all-metal high-vacuum bakable gate valve is described t hat is designed to attach between an electron gun and an experimental high- power microwave tube. It is designed with a minimal radial extent in order to fit within the 20 cm bore of a magnet that encloses the microwave tube. It also provides a continuous cylindrical metal boundary condition for the electron beam. The valve is used to maintain the electron gun vacuum when t he remainder of the tube is brought up to atmospheric pressure for modifica tions. (C) 1999 American Institute of Physics. [S0034-6748(99)02709-4].