N.Ya. Rukhlyada1, V.P. Marin2

1 National Research Nuclear University "MEPHI" (Moscow, Russia)
2 MIREA – Russian University of Technology (Moscow, Russia)
 

To generate electromagnetic waves of the ultrahigh frequency (microwave) range, free electrons are needed. Heated bodies can serve as a source of such electrons. For these purposes, effective thermocathodes have been developed in radio electronics, one of the types of which are metal-porous cathodes (MPCs). For several decades, this type of cathodes have been used in the design of various radar devices. The output parameters of such devices, such as durability, power, and frequency characteristics depend on the reliability of the electron source cathode. In the process of using MPG, it was necessary to increase the cathode emission current density. Work on improving the IPC was carried out all the time. Patented by the Soviet scientist Figner in the sixties of the last century, the cathode containing scandium in a porous matrix showed unique emission properties and found application in instrumentation. The low work output (high emission) caused irteres among the researchers. The efforts undertaken did not lead to the construction of a generally accepted model of the mechanism of operation of the scandate cactode.

The purpose of the work. An attempt to create a model explaining the mechanism and the daring work of the output of the scandate cathode.

A brief literature review of the standard cathode is made.The modern idea of the cathode output operation, depending on the volumetric and surface properties of the substance, is formulated. It is shown that the dipole barrier on the surface plays an essential role in the formation of the output operation. Experimental and theoretical data on the values of surface barriers of a number of elements are presented. The low value of the scandium surface barrier was noted. Being on the surface of a metal-porous cathode, as part of a tungsten sponge, scandium, having a surface barrier value of 2.05 eV, makes a significant contribution to the emission.

It is proposed to produce a metal-porous cathode with a yttrium content in a tungsten sponge having a surface barrier value of 2.85 eV.

Rukhlyada N.Ya., Marin V.P. About the physical mechanism of the scandalous cathode. Science Intensive Technologies. 2022. V. 23. № 8. P. 5−14. DOI: https://doi.org/10.18127/j19998465-202208-01 (in Russian)

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