Title :
4.3: SWNT fiber field emission cathodes
Author :
Fairchild, Steven B. ; Maruyama, Benji ; Boeckl, John J. ; Shiffler, Donald A. ; Lockwood, Nathaneil P. ; Pasquali, Matteo ; Young, Colin
Author_Institution :
Mater. & Manuf. Directorate, Air Force Res. Lab., Wright-Patterson AFB, OH, USA
Abstract :
Small diameter, high current density electron beams are needed for the small beam tunnels required for high frequency traveling wave tube (TWT) amplifiers. The Air Force Research Laboratory (AFRL) began research on small diameter (<;100μm) single fiber DC cathodes for this application. Two types of fibers were tested. Fibers made from graphite were compared to fibers made solely from single walled carbon nanotubes (SWNTs) that are densely packed and highly aligned along the axial direction. Graphite fiber cathodes suffered serious degradation due to joule heating after only 25 hours of operation while only producing up to 200μA of current. SWNT fiber cathodes produced approximately 3mA of current for hundreds of hours while showing minimal physical damage.
Keywords :
carbon nanotubes; current density; electron beams; field emission; SWNT fiber field emission cathodes; high current density electron beams; high frequency traveling wave tube amplifiers; single walled carbon nanotubes; small beam tunnels; Cathodes; Electron beams; Optical fiber amplifiers; Optical fiber communication; Optical fiber devices; Optical fiber dispersion; Optical fiber testing; SWNT; Single walled carbon nanotube; fiber cathode; travelling wave tube;
Conference_Titel :
Vacuum Nanoelectronics Conference (IVNC), 2010 23rd International
Conference_Location :
Palo Alto, CA
Print_ISBN :
978-1-4244-7889-7
Electronic_ISBN :
978-1-4244-7888-0
DOI :
10.1109/IVNC.2010.5563214
