Abstract: A method for fabricating slow-wave structures, including electromagnetic meta-material structures, for high-power slow-wave vacuum electronic devices operating in millimeter-wavelength (30 GHz-300 GHz) and terahertz-frequency (300 GHz and beyond) bands of electromagnetic spectrum. The method includes: loading a digital three dimensional model of a slow-wave structure in a memory of a 3D printer, the loaded digital three dimensional model having data therein representative of the slow-wave structure to be fabricated by the 3D printer; loading metal powder material into the 3D printer; and operating the 3D printer to melt the metal powder material in accordance with the loaded three dimensional model of the slow-wave structure and then to solidify the melted layer of the metal powder material to fabricate the slow-wave structure layer by layer.

Abstract: The present disclosure is directed to axial strapping of a multi-core (cascaded) magnetron. The multi-core (cascaded) magnetron includes a cathode and a plurality of cores (anodes) arranged in an axial direction along the cathode. Each of the cores may have a plurality of vanes arranged periodically in an azimuthal direction along a circumference of the cathode and forming by such a way a plurality of resonant cavities. The multi-core (cascaded) magnetron further includes groups of axial straps coupling each of the cores together in the axial direction along the cathode. For example, a first group of axial straps couple the first plurality of vanes of a first core to the second plurality of vanes of a second core. In an embodiment, the axial straps are configured to provide phase synchronization of electromagnetic oscillations induced inside each of the plurality of cores.

Abstract: The present disclosure is directed to axial strapping of a multi-core (cascaded) magnetron. The multi-core (cascaded) magnetron includes a cathode and a plurality of cores (anodes) arranged in an axial direction along the cathode. Each of the cores may have a plurality of vanes arranged periodically in an azimuthal direction along a circumference of the cathode and forming by such a way a plurality of resonant cavities. The multi-core (cascaded) magnetron further includes groups of axial straps coupling each of the cores together in the axial direction along the cathode. For example, a first group of axial straps couple the first plurality of vanes of a first core to the second plurality of vanes of a second core. In an embodiment, the axial straps are configured to provide phase synchronization of electromagnetic oscillations induced inside each of the plurality of cores.

Abstract: A method for fabricating slow-wave structures, including electromagnetic meta-material structures, for high-power slow-wave vacuum electronic devices operating in millimeter-wavelength (30 GHz-300 GHz) and terahertz-frequency (300 GHz and beyond) bands of electromagnetic spectrum. The method includes: loading a digital three dimensional model of a slow-wave structure in a memory of a 3D printer, the loaded digital three dimensional model having data therein representative of the slow-wave structure to be fabricated by the 3D printer; loading metal powder material into the 3D printer; and operating the 3D printer to melt the metal powder material in accordance with the loaded three dimensional model of the slow-wave structure and then to solidify the melted layer of the metal powder material to fabricate the slow-wave structure layer by layer.

Abstract: Bulk metamaterial cathodes for multi-cavity magnetrons characterized by specific metal-thin-wire medium lattice topologies are used to improve the magnetron output characteristics, including faster startup times and higher microwave radiation powers.

Abstract: A method for continuous casting of light-alloy ingots, consisting in pouring a melt, acting upon the melt with ultrasound using at least one radiator to purify the melt and to refine the structure of the solidifying ingot, the radiation being applied uniformly throughout the cross-section of the melt in an intensity of 2 to 60 W/cm.sup.2 depending on the cross-sectional area of the solidifying ingot, the radiator being immersed into the melt to a depth equal to between 1/12 and 1/4 of the sound wavelength in the material of the melt and the melt temperature being maintained by 60.degree. to 150.degree. C. above the liquidus temperature of the melt, and subsequently withdrawing the ingot.