Tubes in which two electron streams of different velocities interact with one another, e.g. electron-wave tube

Full Title

Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons (details of transit-time tubes H01J23/00; particle accelerators H05H) > Travelling-wave tubes; Tubes in which a travelling wave is simulated at spaced gaps > Tubes in which two electron streams of different velocities interact with one another, e.g. electron-wave tube