Thermionic Emission Characterization of M-Type Cathodes Using Kelvin Probe in an Ultra-High Vacuum Environment

Antonio M. Mantica; Michael J. Detisch; T. John Balk

doi:10.1109/TED.2023.3251963

Thermionic Emission Characterization of M-Type Cathodes Using Kelvin Probe in an Ultra-High Vacuum Environment

Antonio M. Mantica, Michael J. Detisch, T. John Balk

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Thermionic emission characterization is vital for understanding the performance and lifetime of the many vacuum electron devices (VEDs) that make use of cathodes. To characterize the performance of thermionically emitting cathode surfaces with efficiency in one test setup, the Cathode Characterization Chamber (C<inline-formula> <tex-math notation="LaTeX">$^{\text{3}}$</tex-math> </inline-formula>) has been assembled at the University of Kentucky. The C<inline-formula> <tex-math notation="LaTeX">$^{\text{3}}$</tex-math> </inline-formula> principally monitors the work function change and the current density emitted by thermionic surfaces using a Kelvin probe in an ultra-high vacuum (UHV) chamber (approaching 10<inline-formula> <tex-math notation="LaTeX">$^{-\text{10}}$</tex-math> </inline-formula> torr). The chamber also employs ion polishing, optical pyrometry, and residual gas analysis to produce a single comprehensive cathode characterization apparatus. One widely used cathode in VEDs is the M-type cathode, developed in the mid-1960s. M-type cathodes are useful because of their relatively high current densities of emission (<inline-formula> <tex-math notation="LaTeX">$<$</tex-math> </inline-formula>10 A/cm<inline-formula> <tex-math notation="LaTeX">$^{\text{2}}$</tex-math> </inline-formula>) at only moderately high activation temperatures (<inline-formula> <tex-math notation="LaTeX">$<$</tex-math> </inline-formula>1100 <inline-formula> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula>C) for tens of thousands of hours. Using the M-type cathode as a “standard candle”, the capabilities and limits of the C<inline-formula> <tex-math notation="LaTeX">$^{\text{3}}$</tex-math> </inline-formula> are highlighted here and the results are compared to those from pure tungsten samples—all of which are presented as a powerful and comprehensive tool for thermionic emission characterization.

Original language	English
Pages (from-to)	1-8
Number of pages	8
Journal	IEEE Transactions on Electron Devices
DOIs	https://doi.org/10.1109/TED.2023.3251963
State	Accepted/In press - 2023

Bibliographical note

Publisher Copyright:
IEEE

Keywords

Cathode
Cathodes
Current density
Heating systems
Kelvin
Kelvin probe
M-type cathode
Probes
Surface morphology
Thermionic emission
electron emission
thermionic emission
vacuum electron device (VED)

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

Access to Document

10.1109/TED.2023.3251963

Cite this

@article{48fb388fe78e41e1b9fe5d9a98f716a3,

title = "Thermionic Emission Characterization of M-Type Cathodes Using Kelvin Probe in an Ultra-High Vacuum Environment",

abstract = "Thermionic emission characterization is vital for understanding the performance and lifetime of the many vacuum electron devices (VEDs) that make use of cathodes. To characterize the performance of thermionically emitting cathode surfaces with efficiency in one test setup, the Cathode Characterization Chamber (C $^{\text{3}}$ ) has been assembled at the University of Kentucky. The C $^{\text{3}}$ principally monitors the work function change and the current density emitted by thermionic surfaces using a Kelvin probe in an ultra-high vacuum (UHV) chamber (approaching 10 $^{-\text{10}}$ torr). The chamber also employs ion polishing, optical pyrometry, and residual gas analysis to produce a single comprehensive cathode characterization apparatus. One widely used cathode in VEDs is the M-type cathode, developed in the mid-1960s. M-type cathodes are useful because of their relatively high current densities of emission ( $<$ 10 A/cm $^{\text{2}}$ ) at only moderately high activation temperatures ( $<$ 1100 $^{\circ}$ C) for tens of thousands of hours. Using the M-type cathode as a “standard candle”, the capabilities and limits of the C $^{\text{3}}$ are highlighted here and the results are compared to those from pure tungsten samples—all of which are presented as a powerful and comprehensive tool for thermionic emission characterization.",

keywords = "Cathode, Cathodes, Current density, Heating systems, Kelvin, Kelvin probe, M-type cathode, Probes, Surface morphology, Thermionic emission, electron emission, thermionic emission, vacuum electron device (VED)",

author = "Mantica, {Antonio M.} and Detisch, {Michael J.} and Balk, {T. John}",

note = "Publisher Copyright: IEEE",

year = "2023",

doi = "10.1109/TED.2023.3251963",

language = "English",

pages = "1--8",

}

TY - JOUR

T1 - Thermionic Emission Characterization of M-Type Cathodes Using Kelvin Probe in an Ultra-High Vacuum Environment

AU - Mantica, Antonio M.

AU - Detisch, Michael J.

AU - Balk, T. John

N1 - Publisher Copyright: IEEE

PY - 2023

Y1 - 2023

N2 - Thermionic emission characterization is vital for understanding the performance and lifetime of the many vacuum electron devices (VEDs) that make use of cathodes. To characterize the performance of thermionically emitting cathode surfaces with efficiency in one test setup, the Cathode Characterization Chamber (C $^{\text{3}}$ ) has been assembled at the University of Kentucky. The C $^{\text{3}}$ principally monitors the work function change and the current density emitted by thermionic surfaces using a Kelvin probe in an ultra-high vacuum (UHV) chamber (approaching 10 $^{-\text{10}}$ torr). The chamber also employs ion polishing, optical pyrometry, and residual gas analysis to produce a single comprehensive cathode characterization apparatus. One widely used cathode in VEDs is the M-type cathode, developed in the mid-1960s. M-type cathodes are useful because of their relatively high current densities of emission ( $<$ 10 A/cm $^{\text{2}}$ ) at only moderately high activation temperatures ( $<$ 1100 $^{\circ}$ C) for tens of thousands of hours. Using the M-type cathode as a “standard candle”, the capabilities and limits of the C $^{\text{3}}$ are highlighted here and the results are compared to those from pure tungsten samples—all of which are presented as a powerful and comprehensive tool for thermionic emission characterization.

AB - Thermionic emission characterization is vital for understanding the performance and lifetime of the many vacuum electron devices (VEDs) that make use of cathodes. To characterize the performance of thermionically emitting cathode surfaces with efficiency in one test setup, the Cathode Characterization Chamber (C $^{\text{3}}$ ) has been assembled at the University of Kentucky. The C $^{\text{3}}$ principally monitors the work function change and the current density emitted by thermionic surfaces using a Kelvin probe in an ultra-high vacuum (UHV) chamber (approaching 10 $^{-\text{10}}$ torr). The chamber also employs ion polishing, optical pyrometry, and residual gas analysis to produce a single comprehensive cathode characterization apparatus. One widely used cathode in VEDs is the M-type cathode, developed in the mid-1960s. M-type cathodes are useful because of their relatively high current densities of emission ( $<$ 10 A/cm $^{\text{2}}$ ) at only moderately high activation temperatures ( $<$ 1100 $^{\circ}$ C) for tens of thousands of hours. Using the M-type cathode as a “standard candle”, the capabilities and limits of the C $^{\text{3}}$ are highlighted here and the results are compared to those from pure tungsten samples—all of which are presented as a powerful and comprehensive tool for thermionic emission characterization.

KW - Cathode

KW - Cathodes

KW - Current density

KW - Heating systems

KW - Kelvin

KW - Kelvin probe

KW - M-type cathode

KW - Probes

KW - Surface morphology

KW - Thermionic emission

KW - electron emission

KW - thermionic emission

KW - vacuum electron device (VED)

UR - http://www.scopus.com/inward/record.url?scp=85149304975&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85149304975&partnerID=8YFLogxK

U2 - 10.1109/TED.2023.3251963

DO - 10.1109/TED.2023.3251963

M3 - Article

AN - SCOPUS:85149304975

SP - 1

EP - 8

ER -

Thermionic Emission Characterization of M-Type Cathodes Using Kelvin Probe in an Ultra-High Vacuum Environment

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this