Distribution of desorption products on interior surfaces of scandate cathode test vehicle

Mujan N. Seif, Sydney Kolnsberg, Thomas John Balk, Matthew J. Beck, Bernard K. Vancil

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

Scandate cathodes have shown a higher emitted current density than any of its predecessors, which is hypothesized to stem from chemical complexes on the W matrix surface. Therefore, it is crucial to examine the cathodes' desorption behavior to understand how surface chemistry evolves during cathode lifetime. In this work, the distribution of desorption products of scandate cathode activation and operation mapped with XPS and EDX are reported. The compositional studies were conducted on the interior of the glass envelope wherein the cathodes were activated and operated, as well as the anode resting directly atop the cathodes. The results from the glass envelope indicate that Ca is expelled from the surface during pre-activation, not activation. Results from the anode yield insight into the composition and volume of material expelled throughout cathode activation and operation. Lastly, within the detection limits of XPS and EDX, no appreciable Sc was found on the anode nor the glass envelope, suggesting it is not evaporating in great amounts at any stage of cathode lifetime.

Original languageEnglish
Title of host publication2020 IEEE 21st International Conference on Vacuum Electronics, IVEC 2020
Pages375-376
Number of pages2
ISBN (Electronic)9781538682883
DOIs
StatePublished - Oct 19 2020
Event21st IEEE International Conference on Vacuum Electronics, IVEC 2020 - Monterey, United States
Duration: Oct 19 2020Oct 22 2020

Publication series

Name2020 IEEE 21st International Conference on Vacuum Electronics, IVEC 2020

Conference

Conference21st IEEE International Conference on Vacuum Electronics, IVEC 2020
Country/TerritoryUnited States
CityMonterey
Period10/19/2010/22/20

Bibliographical note

Funding Information:
This work was financially supported by the Defense Advanced Research Projects Agency (DARPA) Innovative Vacuum Electronics Science and Technology (INVEST) program, under grant number N66001-16-1-4041.

Publisher Copyright:
© 2020 IEEE.

Keywords

  • Desorption
  • EDX
  • Scandate cathode
  • XPS

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Instrumentation

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