scholarly journals Evolvement Investigation of Secondary Electron Emission for Ultrathin MgO Coatings Prepared by Atomic Layer Deposition

2021 ◽  
Vol 11 (11) ◽  
pp. 4801
Author(s):  
Xiangping Zhu ◽  
Junjiang Guo ◽  
Xiangxin Li ◽  
Rundong Zhou ◽  
Dan Wang ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Coating Thickness ◽  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Atomic Layer ◽  
Emission Layer ◽  
Layer Deposition ◽  
20 Nm ◽  
Semi Empirical

MgO is a kind of high secondary electron yield (SEY) material with important applications in electron multipliers. MgO coatings can be used as the electron emission layer for multiplier dynode to improve the electron gain significantly. However, the SEY investigation on ultrathin MgO coatings is not complete and needed to be supplemented urgently. In this work, a series of MgO coatings with increasing thickness were prepared by atomic layer deposition. SEY properties and energy spectra were characterized, and the effect of coating thickness on SEY was systematically analyzed. Experimental results show that SEY of MgO/Si samples rises as the coating thickness increases. Merely, SEY almost does not change with the coating thickness when the thickness exceeds 30 nm. Then, a SEY semi-empirical theory was employed to interpret the SEY regularities of MgO coatings by regarding the coating samples as ideal double-layer structures. Theoretical calculation quantitatively explained the SEY variation observed during the experiments, and further quantified the SEY contribution level of top coating and bottom substrate for the 1 nm and 20 nm MgO coatings. The work is of great significance for comprehending the SEY of ultrathin MgO coatings and expanding the applications of nanoscale coatings with high SEY.

scholarly journals Secondary electron emission characteristics of Al2O3 coatings prepared by atomic layer deposition

AIP Advances ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 095303 ◽  
Author(s):  
Junjiang Guo ◽  
Dan Wang ◽  
Yantao Xu ◽  
Xiangping Zhu ◽  
Kaile Wen ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Atomic Layer ◽  
Emission Characteristics ◽  
Layer Deposition

Properties of microchannel plate emission layer deposited by atomic layer deposition

2016 ◽  
Vol 45 (9) ◽  
pp. 0916002
Author(s):  
丛晓庆 Cong Xiaoqing ◽  
邱祥彪 Qiu Xiangbiao ◽  
孙建宁 Sun Jianning ◽  
李婧雯 Li Jingwen ◽  
张智勇 Zhang Zhiyong ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Microchannel Plate ◽  
Emission Layer ◽  
Layer Deposition

scholarly journals Polyatomic Ion-Induced Electron Emission (IIEE) in Electrospray Thrusters

Aerospace ◽  
2020 ◽  
Vol 7 (11) ◽  
pp. 153
Author(s):  
Jared M. Magnusson ◽  
Adam L. Collins ◽  
Richard E. Wirz
Keyword(s):  
Electron Emission ◽  
Secondary Electron ◽  
Complex Analysis ◽  
Secondary Electron Emission ◽  
State Theory ◽  
Empirical Modeling ◽  
Threshold Velocity ◽  
Molecular Ion ◽  
And Performance ◽  
Semi Empirical

To better characterize the lifetime and performance of electrospray thrusters, electron emission due to electrode impingement by the propellant cation 1-ethyl-3-methylimidazolium (EMI+) has been evaluated with semi-empirical modeling techniques. Results demonstrate that electron emission due to grid impingement by EMI+ cations becomes significant once EMI+ attains a threshold velocity of ∼9×105 cm s−1. The mean secondary electron yield, γ¯, exhibits strong linearity with respect to EMI+ velocity for typical electrospray operating regimes, and we present a simple linear fit equation corresponding to thruster potentials greater than 1 kV. The model chosen for our analysis was shown to be the most appropriate for molecular ion bombardments and is a useful tool in estimating IIEE yields in electrospray devices for molecular ion masses less than ∼1000 u and velocities greater than ∼106 cm s−1. Droplet-induced electron emission (DIEE) in electrospray thrusters was considered by treating a droplet as a macro-ion, with low charge-to-mass ratio, impacting a solid surface. This approach appears to oversimplify back-spray phenomena, meaning a more complex analysis is required. While semi-empirical models of IIEE, and the decades of solid state theory they are based upon, represent an invaluable advance in understanding secondary electron emission in electrospray devices, further progress would be gained by investigating the complex surfaces the electrodes acquire over their lifetimes and considering other possible emission processes.

scholarly journals The Applications of Ultra-Thin Nanofilm for Aerospace Advanced Manufacturing Technology

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3282
Author(s):  
Guibai Xie ◽  
Hongwu Bai ◽  
Guanghui Miao ◽  
Guobao Feng ◽  
Jing Yang ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
High Power ◽  
Manufacturing Industry ◽  
Secondary Electron ◽  
Atomic Layer ◽  
Manufacturing Technology ◽  
Advanced Manufacturing Technology ◽  
Advanced Manufacturing ◽  
Aerospace Manufacturing ◽  
Layer Deposition

With the development of industrial civilization, advanced manufacturing technology has attracted widespread concern, including in the aerospace industry. In this paper, we report the applications of ultra-thin atomic layer deposition nanofilm in the advanced aerospace manufacturing industry, including aluminum anti-oxidation and secondary electron suppression, which are critical in high-power and miniaturization development. The compact and uniform aluminum oxide film, which is formed by thermal atomic layer deposition (ALD), can prevent the deep surface oxidation of aluminum during storage, avoiding the waste of material and energy in repetitive production. The total secondary electron yield of the C/TiN component nanofilm, deposited through plasma-enhanced atomic layer deposition, decreases 25% compared with an uncoated surface. The suppression of secondary electron emission is of great importance in solving the multipactor for high-power microwave components in space. Moreover, the controllable, ultra-thin uniform composite nanofilm can be deposited directly on the complex surface of devices without any transfer process, which is critical for many different applications. The ALD nanofilm shows potential for promoting system performance and resource consumption in the advanced aerospace manufacturing industry.

Properties of microchannel plate emission layer deposited by atomic layer deposition

2016 ◽  
Vol 45 (9) ◽  
pp. 916002
Author(s):  
丛晓庆 Cong Xiaoqing ◽  
邱祥彪 Qiu Xiangbiao ◽  
孙建宁 Sun Jianning ◽  
李婧雯 Li Jingwen ◽  
张智勇 Zhang Zhiyong ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Microchannel Plate ◽  
Emission Layer ◽  
Layer Deposition
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