Life of Dispenser Cathodes and Oxide Cathodes in Laminar-Flow Type and Crossover Type Electron Guns

Toshiharu HIGUCHI; Katsuhisa HOMMA; Takahiro KAWAHARADA

Life of Dispenser Cathodes and Oxide Cathodes in Laminar-Flow Type and Crossover Type Electron Guns

Toshiharu HIGUCHI, Katsuhisa HOMMA, Takahiro KAWAHARADA

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Differences in the behavior of dispenser cathodes and oxide cathodes in laminar-flow type and crossover type electron guns were investigated by experiments and simulations under high-current-density conditions. When an oxide cathode is operated under such conditions, the heating effect due to Joule heat in the oxide layer exceeds the cooling effect, depending on the product of the work function and the cathode current, resulting in a rise in the cathode temperature. This rise in cathode temperature aggravates deterioration of emission characteristics during the life of an oxide cathode. In the case of the dispenser cathode, however, the cathode temperature decreases under high-current-density conditions. When an oxide cathode in a crossover type electron gun is operated, equipotential surfaces are formed in the curved surface in the oxide layer. The formation of an equipotential surface leads to relaxation of the loading. It is considered that this is the reason for the longer life of an oxide cathode in a crossover type electron gun than that of an oxide cathode in a laminar-flow type electron gun.

Publication: IEICE TRANSACTIONS on Electronics Vol.E81-C No.11 pp.1703-1710

Publication Date: 1998/11/25

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Type of Manuscript: Special Section PAPER (Special Issue on Electronic Displays)

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Toshiharu HIGUCHI, Katsuhisa HOMMA, Takahiro KAWAHARADA, "Life of Dispenser Cathodes and Oxide Cathodes in Laminar-Flow Type and Crossover Type Electron Guns" in IEICE TRANSACTIONS on Electronics, vol. E81-C, no. 11, pp. 1703-1710, November 1998, doi: .
Abstract: Differences in the behavior of dispenser cathodes and oxide cathodes in laminar-flow type and crossover type electron guns were investigated by experiments and simulations under high-current-density conditions. When an oxide cathode is operated under such conditions, the heating effect due to Joule heat in the oxide layer exceeds the cooling effect, depending on the product of the work function and the cathode current, resulting in a rise in the cathode temperature. This rise in cathode temperature aggravates deterioration of emission characteristics during the life of an oxide cathode. In the case of the dispenser cathode, however, the cathode temperature decreases under high-current-density conditions. When an oxide cathode in a crossover type electron gun is operated, equipotential surfaces are formed in the curved surface in the oxide layer. The formation of an equipotential surface leads to relaxation of the loading. It is considered that this is the reason for the longer life of an oxide cathode in a crossover type electron gun than that of an oxide cathode in a laminar-flow type electron gun.
URL: https://global.ieice.org/en_transactions/electronics/10.1587/e81-c_11_1703/_p

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@ARTICLE{e81-c_11_1703,
author={Toshiharu HIGUCHI, Katsuhisa HOMMA, Takahiro KAWAHARADA, },
journal={IEICE TRANSACTIONS on Electronics},
title={Life of Dispenser Cathodes and Oxide Cathodes in Laminar-Flow Type and Crossover Type Electron Guns},
year={1998},
volume={E81-C},
number={11},
pages={1703-1710},
abstract={Differences in the behavior of dispenser cathodes and oxide cathodes in laminar-flow type and crossover type electron guns were investigated by experiments and simulations under high-current-density conditions. When an oxide cathode is operated under such conditions, the heating effect due to Joule heat in the oxide layer exceeds the cooling effect, depending on the product of the work function and the cathode current, resulting in a rise in the cathode temperature. This rise in cathode temperature aggravates deterioration of emission characteristics during the life of an oxide cathode. In the case of the dispenser cathode, however, the cathode temperature decreases under high-current-density conditions. When an oxide cathode in a crossover type electron gun is operated, equipotential surfaces are formed in the curved surface in the oxide layer. The formation of an equipotential surface leads to relaxation of the loading. It is considered that this is the reason for the longer life of an oxide cathode in a crossover type electron gun than that of an oxide cathode in a laminar-flow type electron gun.},
keywords={},
doi={},
ISSN={},
month={November},}

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TY - JOUR
TI - Life of Dispenser Cathodes and Oxide Cathodes in Laminar-Flow Type and Crossover Type Electron Guns
T2 - IEICE TRANSACTIONS on Electronics
SP - 1703
EP - 1710
AU - Toshiharu HIGUCHI
AU - Katsuhisa HOMMA
AU - Takahiro KAWAHARADA
PY - 1998
DO -
JO - IEICE TRANSACTIONS on Electronics
SN -
VL - E81-C
IS - 11
JA - IEICE TRANSACTIONS on Electronics
Y1 - November 1998
AB - Differences in the behavior of dispenser cathodes and oxide cathodes in laminar-flow type and crossover type electron guns were investigated by experiments and simulations under high-current-density conditions. When an oxide cathode is operated under such conditions, the heating effect due to Joule heat in the oxide layer exceeds the cooling effect, depending on the product of the work function and the cathode current, resulting in a rise in the cathode temperature. This rise in cathode temperature aggravates deterioration of emission characteristics during the life of an oxide cathode. In the case of the dispenser cathode, however, the cathode temperature decreases under high-current-density conditions. When an oxide cathode in a crossover type electron gun is operated, equipotential surfaces are formed in the curved surface in the oxide layer. The formation of an equipotential surface leads to relaxation of the loading. It is considered that this is the reason for the longer life of an oxide cathode in a crossover type electron gun than that of an oxide cathode in a laminar-flow type electron gun.
ER -