1.5: Development of field emission cathodes, electron gun and a slow wave structure for a terahertz traveling wave tube

Author

Lockwood, Nathaniel P. ; Cartwright, Keith L. ; Gensheimer, P.D. ; Shiffler, D.A. ; D´Aubigny, Christian Y. ; Walker, Christopher K. ; Young, Abraham ; Fairchild, Steven B. ; Maruyama, Benji

Author_Institution

High Power Microwave Div., Air Force Res. Lab., Kirtland AFB, NM, USA

fYear

2010

fDate

18-20 May 2010

Firstpage

25

Lastpage

26

Abstract

High power terahertz (THz) sources and amplifiers hold the potential to greatly improve remote sensing and high bandwidth communication. To enable these applications, a Traveling Wave Tube (TWT) operating at 0.22 THz and a multi-cathode Field Emission (FE) electron gun are developed and characterized using a Particle-in-Cell simulation. Three candidate high current density cathode materials, Halfnium Carbide (HfC), carbon fibers, and Carbon Nanotubes (CNTs) were tested, characterized and their emission properties compared and used to verify simulations. A current of 3.0 mAmps for a single 100 micron diameter single walled nanotube rope was experimentally achieved and used as the basis of the FE gun design. Simulations of the FE gun and THz TWT were coupled and the effects of multiple and single tip FE gun beam characteristics on the TWT gain, bandwidth, and efficiencies are examined for several beam optic configurations.

Keywords

carbon fibres; carbon nanotubes; cathodes; current density; electron field emission; electron guns; hafnium compounds; power amplifiers; slow wave structures; terahertz wave devices; vacuum microelectronics; FE gun beam characteristics; FE gun design; HfC; Particle-in-Cell simulation; THz TWT; beam optic configurations; carbon fibers; carbon nanotubes; current 3 mA; field emission cathodes; frequency 0.22 THz; halfnium carbide; high-bandwidth communication; high-current density cathode materials; high-power THz amplifiers; high-power terahertz sources; multicathode field emission electron gun; remote sensing; slow wave structure; terahertz traveling wave tube; Bandwidth; Cathodes; Current density; Electron emission; Electron tubes; High power amplifiers; Iron; Optical amplifiers; Optical beams; Remote sensing; ICEPIC; carbon fiber; carbon nanotubes; cathodes; electron beam; electron gun; field emission; particle-in-cell; terahertz; terahertz amplifier; traveling wave tube;

fLanguage

English

Publisher

ieee

Conference_Titel

Vacuum Electronics Conference (IVEC), 2010 IEEE International

Conference_Location

Monterey, CA

Print_ISBN

978-1-4244-7098-3

Type

conf

DOI

10.1109/IVELEC.2010.5503622

Filename

5503622