Studies on the pressed yttrium oxide-tungsten matrix as a possible dispenser cathode material

Yang, Fan; Wang, Jinshu; Liu, Wei; Liu, Xiang; Zhou, Meiling

doi:10.1016/j.matchemphys.2014.10.019

Cited by 13 publications

(2 citation statements)

References 23 publications

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“…The LWF elements were added to cathodes in the form of alloys or compounds, such as Ba, Cs, Hf, BaO, SrO, ThO 2 , LaB 6 , Y 2 O 3 , Gd 2 O 3 , etc. [14][15][16][17][18]. These studies have proved that the addition of LWF elements can increase the electron-emission ability of the cathode and reduce cathode erosion.…”

Section: Introductionmentioning

confidence: 91%

Exploration of a micro multi-electrode technology applied in an air arc heater

Yuan¹,

Liu²,

Zhu³

et al. 2021

J. Phys. D: Appl. Phys.

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Arc heaters are vital equipment for the ground thermal appraisal of space probes reentering Earth’s atmosphere. However, the cathodes of arc heaters are currently made of pure copper, and cathode erosion limits the appraisal. A micro multi-electrode technology was proposed to reduce cathode erosion. Cu–Y, Cu–Ba, Cu–Hf, Cu–La, Cu–Cr2Nb, Cu–LaB6, Cu–HfO2, and Cu–Y2O3 alloys were prepared with a content of mol. 0.3%. The microstructure, electron-emission abilities, and arc-attraction abilities of the prepared alloys were analyzed. These alloys consist of low work function (LWF) phases and copper. The electron-emission abilities of these alloys are 10–30 times higher than that of copper. The LWF phase can attract the arc, and its arc-attraction ability can be characterized by a parameter, . The arc-attraction ability of these LWF phases from low to high is Cu, Cu6Y, Cu6La, Cu13Ba, Cu5Hf, Cr2Nb, HfO2, Y2O3, and LaB6. The arc-attraction ability of the LWF phase is related to its work function and its melting point. Cr2Nb, HfO2, Y2O3, and LaB6 successfully attracted and separated the single arc spot into multiple micro spots, which verified the feasibilty of the micro multi-electrode technology.

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Section: Introductionmentioning

confidence: 91%

Exploration of a micro multi-electrode technology applied in an air arc heater

Yuan¹,

Liu²,

Zhu³

et al. 2021

J. Phys. D: Appl. Phys.

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“…The secondary electron emission (SEE) process is important for various vacuum electronic devices, such as scanning electron microscopes, atomic clocks, alternating current plasma display panels, and electron/photomultipliers for mass spectroscopy, photoelectron spectrometers, magnetrons, and crossed-field amplifiers [1][2][3][4][5]. A variety of materials are selected to satisfy specific requirements for enhancing or suppressing the secondary electron yield (δ) [6].…”

Section: Introductionmentioning

confidence: 99%

Surface Characterization and Secondary Electron Emission Properties of Alumina Containing MgO Film on Ag-Mg-Al Alloy

Zhou

Zhang

Wang

et al. 2018

Metals

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Ag-Mg alloy is used as a dynode material in electron multiplier tubes due to the high secondary electron yields (δ) of the surface of MgO film. However, MgO film is readily degraded under strong electron or ion bombardment, which results in a decrease in the lifetime of devices. In this study, alumina-containing MgO films of ~50–150 nm were developed on a Ag-2Mg-2Al alloy (silver alloy containing 2 wt % Mg and 2 wt % Al) after a thermal activation process performed at 500–600 °C under low oxygen pressures of 5.0–20.0 Pa. Auger electron spectroscopy and X-ray photoelectron spectroscopy analyses reveal that the film consists of a thin layer of pure MgO and a relatively thicker layer of alumina-containing MgO located beneath the top MgO layer. The alumina-containing MgO film exhibits high δ value of 7.7 at a primary electron energy of 580 eV and a much better stability under energetic electron bombardment than pure MgO film on Ag-Mg alloy. Alumina has higher bond dissociation energy than MgO, and the presence of alumina in the film contributes to mitigating the dissociation of the MgO film under electron bombardment. The Ag-2Mg-2Al alloy with alumina-containing MgO film is a promising candidate as a dynode material for electron multiplier tubes.

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