Microstructure characterization and thermionic emission performance of barium-tungsten cathode

Wang Ziyu; Shang Jihua; Yang Xinyu; Zhang Jiuxing

doi:10.11884/HPLPB202133.200335

Volume 33 Issue 5

May 2021

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Wang Ziyu, Shang Jihua, Yang Xinyu, et al. Microstructure characterization and thermionic emission performance of barium-tungsten cathode[J]. High Power Laser and Particle Beams, 2021, 33: 053001. doi: 10.11884/HPLPB202133.200335

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Wang Ziyu, Shang Jihua, Yang Xinyu, et al. Microstructure characterization and thermionic emission performance of barium-tungsten cathode[J]. High Power Laser and Particle Beams, 2021, 33: 053001. doi: 10.11884/HPLPB202133.200335

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Microstructure characterization and thermionic emission performance of barium-tungsten cathode

doi: 10.11884/HPLPB202133.200335

School of Material Science and Engineering, Hefei University of Technology, Hefei 230009, China

Received Date: 2020-12-14
Rev Recd Date: 2021-03-21

Available Online: 2021-04-10

Publish Date: 2021-05-20

Abstract

Abstract

The effect of the parameters (sintering temperature, pressure, holding time) of spark plasma sintering technique on the W porosity of Ba-W cathode was studied by orthogonal method. When the W porosity varied in the range of 23%−30%, the corresponding process parameters were obtained. On this basis, the spherical and traditional irregular W matrix with different porosity were sintered. The results show that the spherical porous W particles were packed and arranged orderly, and the pore size distribution was concentrated and uniform. When the porosity of spherical W was 26.3%, the size of the median pore was 1.41 μm. The vickers hardness of spherical tungsten matrix was lower than that of conventional irregular tungsten matrix. Under the condition of pulse width 10 μs and frequency 1000 Hz, the impulse current density of Ba-W cathode increased at first and then decreased with the increase in porosity. The maximum current density belonged to the Ba-W cathode with the matrix porosity of 26.3%. At 1050 ℃, the off-point emission current density of Ba-W cathode reached 24.62 A/cm², the corresponding zero-field current density and workfunction were 7.62 A/cm² and 1.95 eV, respectively.
- spark plasma sintering,
- barium-tungsten cathode,
- spherical tungsten powders,
- porosity,
- thermionic emission property

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References(23)

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