Yu.G. Gamayunov - Dr. Sc. (Phys.-Math.), Professor, Saratov State University named after N.G. Chernyshevsky. E-mail: GamayunovYG@info.sgu.ru E.V. Patrusheva - Ph. D. (Phys.-Math.), Research Scientist, Saratov State University named after N.G. Chernyshevsky. E-mail: PatrushevaEV@info.sgu.ru Yu.A. Grigoriev - Dr. Sc. (Phys.-Math.), Professor, Leading Research Scientist, Saratov branch of Kotel\'nikov IRE of RAS. E-mail: grig@soire.renet.ru A.A. Burtsev - Ph. D. (Eng.), Head of Laboratory «», JSC «SPE «Almaz» (Saratov), Associate Professor, Yuri Gagarin State Technical University of Saratov. E-mail: antbourtsew@gmail.com

The paper presents the results of numerical simulation and experimental study of electron gun with a linear compression of 4,4 of sheet beam based a blade thermionic minicathode for TWT at terahertz frequencies. In this paper, we propose a variant of the electron gun with a compression beam on the basis of previous results in the optics work in order to increase the beam current density in the beam tunnel. From the calculation of the interaction space of the electron beam with the electromagnetic wave, it is shown that the beam current value reaches 90 mA and the transverse dimension of the beam tunnel is to be 0.2 mm at the frequency range up to 200 GHz. Calcu-lation of the formation of extended electron beams of low-perveance is conducted including influence of the initial thermal velocities of the electrons. The results of modeling the electron gun with sheet electron beam with blade cathode with dimensions of 0,2×0,7 mm are performed. The beam transport is carried out under magnetic field with amplitude of 0.7 T. The beam thickness in the tunnel is 0.045 mm which corresponds to 4.4 of linear compression. A plane of symmetry corner relatively to the beam focusing electrode has 72°. In this case, the sheet beam simulation generated by electron gun has shown feasibility of beam of low-perveance with low deformation. Rms emittance beam εrms in the beam tunnel does not exceed of 0,6-10−7 π?m-rad. The current density in the beam reaches 283 A / cm2. Using discharge machining, dispenser cathode at operating temperature 1200°C and a focusing grid were fabricated to experimental test of the electron gun layout. During I-V experimental test of triode electron gun in a vacuum, there have been a moving anode with diameter D = 2 mm. As a result of experimental measurements diode I-V characteristic in the pulsed mode (duty factor 0.05%, pulse duration τ = 10 μs), the current density is 264 A / cm2 has obtained at cathode current of 84 mA, and an control grid voltage of 1200 V.

 

1. Gamayunov Y.G., Toreev A.I., Patrusheva E.V., and other. Simulation of Electron-Optical Forming Systems with Highly Compressed Electron Beams // Journal of Communications Technology and Electronics. 2008. V. 3. № 3. P. 323−332.
2. Bushuev N.A., Grigoriev Y.A., Burtsev A.A., Navrotsky I.A., Sahajee G.V. Forming of High Current Density Sheet Electron Beams for Sub-THZ TWT Vacuum Amplifiers // The Proceedings of the 15th IEEE International Vacuum Electronics Conference, California. 2014. P. 171−172.