Scandate Dispenser Cathode Fabrication for A High-Aspect-Ratio High-Current-Density Sheet Beam Electron Gun

作者：Zhao Jinfeng^*; Gamzina Diana; Li Na; Li Ji; Spear Alexander G; Barnett Larry; Banducci Mike; Ri**ud Subhash; Luhmann Neville C Jr

来源：IEEE Transactions on Electron Devices, 2012, 59(6): 1792-1798.

DOI：10.1109/TED.2012.2190294

• Electron gun analyzer
• high current density
• scandate dispenser cathode
• sheet beam

A high-current-density scandate tungsten dispenser cathode was used for the demonstration of a 25 : 1-aspect-ratio 750-A/cm(2)-current-density sheet beam for the Defence Advanced Research Project Agency High-Frequency Integrated Vacuum Electronics (HiFIVE) program intended for the realization of a wideband (similar to 30%) 220-GHz traveling wave tube. The elliptical cathode with homogeneous microstructure was made from 1-2-mu m-size tungsten powder added with nanosized Scandia using the sol-gel method; it has a current density of up to 160 A/cm(2) at 1050 degrees C. A sheet beam gun analyzer was built to test the terahertz sheet beam gun and determine the size and current density of a sheet electron beam produced by the impregnated scandate tungsten dispenser cathode. A sheet electron beam with an aspect ratio of 12.5 : 1 with a current density exceeding 375 A/cm(2) has been obtained using a BVERI impregnated scandate dispenser cathode without magnetic compression; further magnetic field compression would give the final current density of 750 A/cm(2).

• 出版日期2012-6