Results of developing, research and application of electron-optical devices of millimeter wavelength range

The development of electronic amplifiers and sources of millimeter and submillimeter wave ranges is closely associated with the problems of forming and transporting super-thin electron beams with high current density. For relatively low (1-15 kV) accelerating voltages, the required suppression of the disturbing effects of heat velocities, space charge, the cathode and anode lenses, and man-made aberrations can be ensured only by electron-optical systems (EOS) with rectangular optics and a magnetic field limited beam. In order to design EOS with magnetic field limited beams, the following methods and devices should be developed: high-emission cathodes; small-size magnetic focusing systems (MFS) with high (0.3 to 1 T) induction inside the beam and small weight; theoretical methods for studying the structure of the induced thin beams providing for the disperse structure of the EOS elements; experimental methods for studying the properties of thin electron beams with high reference power under real operation conditions. In this paper, we discuss the results of development, study and use of EOS, that form plane and axially-symmetrical beams with the cross dimensions of 0.05 to 0.2 mm and current density up to 100 A/cm/sup 2/, which are applied in backward wave tubes (BWT), traveling wave tubes (TWT) and orotrons in mm- and submm-wave ranges.