Experimental Study and Theoretical Model for Increasing the Current Density of Thermionic Cathodes through Active Impregnant Substance

Shengyi YIN; Xinping LÜ; Feng REN; Zhipeng LU; Xinxin WANG; Yu WANG; Jiao HAN; Qi ZHANG; Yang LI

doi:10.11999/JEIT210087

Volume 43 Issue 10

Oct. 2021

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Article Navigation > Journal of Electronics & Information Technology > 2021 > 43(10): 3058-3067

Shengyi YIN, Xinping LÜ, Feng REN, Zhipeng LU, Xinxin WANG, Yu WANG, Jiao HAN, Qi ZHANG, Yang LI. Experimental Study and Theoretical Model for Increasing the Current Density of Thermionic Cathodes through Active Impregnant Substance[J]. Journal of Electronics & Information Technology, 2021, 43(10): 3058-3067. doi: 10.11999/JEIT210087

Citation:

Shengyi YIN, Xinping LÜ, Feng REN, Zhipeng LU, Xinxin WANG, Yu WANG, Jiao HAN, Qi ZHANG, Yang LI. Experimental Study and Theoretical Model for Increasing the Current Density of Thermionic Cathodes through Active Impregnant Substance[J]. Journal of Electronics & Information Technology, 2021, 43(10): 3058-3067. doi: 10.11999/JEIT210087

Citation:

Shengyi YIN, Xinping LÜ, Feng REN, Zhipeng LU, Xinxin WANG, Yu WANG, Jiao HAN, Qi ZHANG, Yang LI. Experimental Study and Theoretical Model for Increasing the Current Density of Thermionic Cathodes through Active Impregnant Substance[J]. Journal of Electronics & Information Technology, 2021, 43(10): 3058-3067. doi: 10.11999/JEIT210087

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Experimental Study and Theoretical Model for Increasing the Current Density of Thermionic Cathodes through Active Impregnant Substance

doi: 10.11999/JEIT210087

1.
Key Laboratory of High Power Microwave Sources and Technologies, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
2.
University of Chinese Academy of Sciences, Beijing 100049, China

Funds: National Key R&D Program of China (2018YFB1105200)

Received Date: 2021-01-21
Rev Recd Date: 2021-04-19

Available Online: 2021-05-07

Publish Date: 2021-10-18

Abstract

Abstract

Developing new active substance composition system and its preparation method to enhance scandate cathode’s emission property is a hotspot in the research field of thermionic cathode especially high-emission cathode. A novel highly active impregnant substance consisting of polymetallic oxide which apparently increases scandium’s appending proportion and greatly enhances cathode’s emission current density is put forward in this paper. Freeze-drying method is applied into preparation of the active substance’s precursor and effectively solves the problem of inhomogeneity and uncontrollability in the mechanical crushing, grinding and mixing procedures of conventional solid-phase synthesis routine. Cathode which adopted novel composition system and substance acquired by new preparation routine reaches a pulse emission current density of above 500 A/cm² under close-spaced diode configuration and 218.5 A/cm² in an electron gun. Under the DC diode experimental configuration, the cathodes’ emission lifetime test has endured for 10500 hours with no emission current drop; while in the electron gun with a pulse drive of heavy duty cycle (5%), the cathode maintains a big workload of more than 50 A/cm² after having worked for 2010 hours. Via Deep UltraViolet laser-Photo Emission and Thermal Emission Electron Microscopy (DUV-PEEM/TEEM) analyzation, the phenomenon ofthermionic emission points’ amount increases and emitting micro-area expands on the newly prepared high-emission cathode’s surface is observed. Finally, a ‘binary tree’ emission model is brought up, hoping to explain the physical mechanism of scandate cathode’s high emission character with new active substance.
- Impregnated dispenser cathode,
- Electron emission,
- Liquid phase synthesis,
- Freeze-drying method

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References(27)

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