Desorption from hot scandate cathodes: Effects on vacuum device interior surfaces after long-term operation

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Scandate cathodes have exhibited superior emission properties compared to current state-of-the-art “M-type” thermionic cathodes. However, their integration into vacuum devices is limited in part by a lack of knowledge regarding their functional lifespan and behavior during operation. Here, we consider thermal desorption from scandate cathodes by examining the distribution of material deposited on interior surfaces of a sealed vacuum device after ~26,000 h of cathode operation. XPS, EDS, and TEM analyses indicate that on the order of 1 wt.% of the initial impregnate is desorbed during a cathode’s lifetime, Ca does not desorb uniformly with time, and little to no Sc desorbs from the cathode surfaces (or does so at an undetectable rate). Findings from this first-ever study of a scandate cathode after extremely long-time operation yield insight into the utility of scandate cathodes as components in vacuum devices and suggest possible effects on device performance due to deposition of desorption products on interior device surfaces.

Original languageEnglish
Article number5149
Pages (from-to)1-21
Number of pages21
JournalMaterials
Volume13
Issue number22
DOIs
StatePublished - Nov 2 2020

Bibliographical note

Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Keywords

  • Desorption
  • Electron devices
  • Scandate cathodes
  • Vacuum electronics

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics

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