Field emission testing of carbon nanotubes for THz frequency vacuum microtube sources
Abstract
A carbon nanotube-based high current density electron field emission source is under development at Jet Propulsion Laboratory (JPL) for submillimeter-wave power generation (300 GHz to 3 THz). This source is the basis for a novel vacuum microtube component: the nanoklystron. The nanoklystron is a monolithically fabricated reflex klystron with dimensions in the micrometer range. The goal is to operate this device at much lower voltages than would be required with hot-electron sources and at much higher frequencies than have ever been demonstrated. Both single-walled (SWNTs) as well as multi-walled nanotubes (MWNTs) are being tested as potential field-emission sources. This paper presents initial results and observations of these field emission tests. SWNTs and MWNTs were fabricated using standard CVD techniques. The tube density was higher in the case of MWNT samples. As previously reported, high-density samples suffered from enhanced screening effect thus decreasing their total electron emission. The highest emission currents were measured from disordered, less dense MWNTs and were found to be ~0.63 mA @ 3.6 V/μm (sample 1) and ~3.55 mA @ 6.25 V/μm (sample 2). The high density vertically aligned MWNTs showed low field emission as predicted: 0.31 mA @ 4.7 V/μm.
Additional Information
© 2003 Society of Photo-Optical Instrumentation Engineers (SPIE). This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with National Aeronautics and Space Administration (NASA). This work was funded by NASA's Code-R grants and JPL's Director's Research and Development Fund. Authors would like to thank Colleen Marrese of JPL and Dr. James Hone of California Institute of Technology (currently at Columbia University) for their initial help.Attached Files
Published - 227.pdf
Files
Name | Size | Download all |
---|---|---|
md5:648fad4a3a546c27f694afd38c2dbdfc
|
374.9 kB | Preview Download |
Additional details
- Eprint ID
- 87690
- Resolver ID
- CaltechAUTHORS:20180710-095629084
- NASA/JPL/Caltech
- JPL Director's Research and Development Fund
- Created
-
2018-07-10Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 5343