Investigation of terahertz sheet beam traveling wave tube amplifier with nanocomposite cathode

• Published in: Physics of plasmas 2010-12, Vol.17 (12), p.123105-123105-4
• Main Authors: Shin, Young-Min, Zhao, Jinfeng, Barnett, Larry R., Luhmann, Neville C.
• Format: Article
• Language: English
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLIFIERS; BEAM-PLASMA SYSTEMS; BEAMS; CATHODES; CHALCOGENIDES; COMPOSITE MATERIALS; CURRENT DENSITY; ELECTRODES; ELECTRON BEAMS; ELECTRON TUBES; ELECTRONIC EQUIPMENT; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; LEPTON BEAMS; MATERIALS; MICROWAVE EQUIPMENT; MICROWAVE TUBES; NANOSTRUCTURES; OXIDES; OXYGEN COMPOUNDS; PARTICLE BEAMS; PLASMA SIMULATION; SCANDIUM COMPOUNDS; SCANDIUM OXIDES; SIMULATION; TRANSITION ELEMENT COMPOUNDS; TRAVELLING WAVE TUBES
• ISSN: 1070-664X; 1089-7674
• DOI: 10.1063/1.3525098

Particle-in-cell simulations of a staggered double grating array traveling wave tube intended as a wideband amplifier for terahertz communications, sensing, and imaging applications showed that, for an electron beam power of 5 kW, it produces 150–275 W, corresponding to 3%–5.5% electronic efficiency, at 0.22 THz with over ∼ 30 % bandwidth and with greater than 12 dB/cm growth rate. The circuit has been fabricated by both UV lithography and high precision computer-numerical-control machining with ∼ 2 – 3   μ m dimensional tolerance and ∼ 50   nm surface roughness. A scandate nanocomposite ( Sc 2 O 3 – W ) cathode for the electron beam source has successfully emitted 120   A / cm 2 (space charge limited) at 1150   ° C and 50   A / cm 2 at 1050   ° C for 8000 h as required to produce the requisite high current density electron beam.