Manufacturing technology and emission properties of metal-porous cathodes modified with nanocarbon structures
Tatiyana M. Krachkovskaya1, Andrey S. Emelyanov1, Rostislav U. Bogachev1, Olga E. Glukhova1,2,3, Dmitry A. Kolosov1,2; 1SC "RPE "Almaz", Saratov, Russia; 2Saratov State University, Saratov, Russia; 3I.M. Sechenov First Moscow State Medical University, Moscow, Russia
Abstract
The improved manufacturing technology and the study of emission properties of M-type metal-porous cathodes modified with polyhedral fulleroid-type nanoparticles of toroidal shape – astralenes in the refractory matrix and carbon nanocluster sulfoadduct – ugleron in the active substance are presented in the article. The new technology of modifying the active substance with ugleron made it possible to increase the homogeneity and identity of the compositions from batch to batch, and the improvement of the manufacturing process of the refractory cathode matrix with astralenes led to an increase in the uniformity of its structure and identity, which allows us to count on the industrial use of such cathodes. The study conducted in the diodes, cathode-grid units and devices showed that cathodes with ugleron have an increased service life due to a decrease in the evaporation rate of the active substance at an operating temperature of the cathode of 1050 °C, which is confirmed by modeling the interaction of nanocarbon structures with the active substance components Ba and BaO using the density functional theory (DFT) using the generalized gradient approximation (GGA) of the Perdew-Burk-Ernzerhof (PBE) implemented in the SIESTA 4.1.5 software package and the determination of the binding energy, and experimentally measured values for barium-calcium aluminate (3BaO∙0.5CaO∙Al2O3) and barium-calcium aluminosilicate (3BaO∙0.5CaO∙Al2O3∙0.5SiO2) by the piezoelectric weighing method; cathodes with astralenes have a higher emission capacity in the space charge limitation mode than similar cathodes without modification. Tests of cathodes modified with ugleron and astralenes in space TWTs have shown that their service life is an order of magnitude greater than the service life of M-type double-layer cathodes commercially used in such devices.
Speaker
Krachkovskaya Tatiyana
SC "RPE "Almaz"
Russia
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