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15 pages, 4332 KiB

Open AccessArticle

Analysis of Structural Boundary Effects of Copper-Coated Films and Their Application to Space Antennas

by Xiaotao Zhou, Huanxiao Li and Xiaofei Ma

Coatings 2023, 13(9), 1612; https://doi.org/10.3390/coatings13091612 - 14 Sep 2023

Viewed by 656

Copper-coated films are a solution for flexible electronic devices. One of the applications is a flexible-tension film-deployable antenna, which is a large deployable space antenna with broad application prospects. To analyze the possibility of applying coated films to the antenna, surface accuracy evaluation [...] Read more.

Copper-coated films are a solution for flexible electronic devices. One of the applications is a flexible-tension film-deployable antenna, which is a large deployable space antenna with broad application prospects. To analyze the possibility of applying coated films to the antenna, surface accuracy evaluation is required. The finite element method (FEM) was used to analyze the surface accuracy of the copper-coated thin-film structures. Both wrinkling and stretching–bending coupling deformation were considered. Simplified models were applied to study factors influencing the surface accuracy under boundary effects. Different sizes of coated area and different boundary conditions were simulated. The results showed the characteristic boundary effects of copper-coated thin-film structures and the influence curve of film thickness and patch size on boundary effects. These findings will inform the design and analysis of variable-stiffness thin-film antennas. On this basis, the application of a flexible-tension film-deployable antenna is discussed, along with a measure to improve the surface accuracy. Full article

(This article belongs to the Special Issue Applications of Advanced Films and Materials in Space Microwave Technologies)

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15 pages, 9995 KiB

Open AccessArticle

Gas Desorption and Secondary Electron Emission from Graphene Coated Copper Due to E-Beam Stimulation

by Guobao Feng, Huiling Song, Yun Li, Xiaojun Li, Guibai Xie, Jian Zhuang and Lu Liu

Coatings 2023, 13(2), 370; https://doi.org/10.3390/coatings13020370 - 6 Feb 2023

Cited by 3 | Viewed by 1411

Abstract

The gas desorption and secondary electron multiplication induced by electron bombardment tend to induce severe low-pressure discharge effects in space microwave device cavities. Nevertheless, few studies have focused on both secondary electron emission and electron-stimulated gas desorption (ESD). Although the suppression of secondary [...] Read more.

The gas desorption and secondary electron multiplication induced by electron bombardment tend to induce severe low-pressure discharge effects in space microwave device cavities. Nevertheless, few studies have focused on both secondary electron emission and electron-stimulated gas desorption (ESD). Although the suppression of secondary electrons by graphene was found to be better in our previous study, it is still unclear whether the surface modification of graphene, which brings about different interfacial states, can also be manifested in terms of ESD. The deep mechanism of gas desorption and secondary electron emission from this extremely thin two-dimensional material under electron bombardment still needs further investigation. Therefore, this paper investigates the mechanism of graphene modification on Cu metal surface on the gas release and secondary electron emission properties under electron bombardment. The surface states of graphene-modified Cu were characterized, and the ESD yield and secondary electron yield of Cu/GoCu were investigated using a self-researched platform and analyzed using molecular dynamics simulations and electron Monte Carlo simulations. The results of the study showed that the most released component on the Cu surface under the bombardment of electrons was H₂O molecules, while the most released component on the GoCu surface was H₂ molecules. The graphene-modified samples showed a significant suppression effect on the secondary electron yield and ESD only in the low-energy region below 400 eV. This study can provide a valuable reference for suppressing low-pressure discharge and multipactor phenomena in space microwave components. Full article

(This article belongs to the Special Issue Applications of Advanced Films and Materials in Space Microwave Technologies)

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12 pages, 3467 KiB

Open AccessArticle

Studies on the Thermodynamic Properties of C/ph Irradiated by Intense Electron Beams

by Peng Lin, Ruohan Chen and Dengwang Wang

Coatings 2022, 12(8), 1128; https://doi.org/10.3390/coatings12081128 - 5 Aug 2022

Viewed by 963

Abstract

The thermal shock wave and blow-off impulse are important phenomena of the thermodynamic effects produced in material bombarded by electron beams. The experimental results of the blow-off impulse in an improved carbon fiber-reinforced phenolic material (referred to, in short, as C/ph) exposed to [...] Read more.

The thermal shock wave and blow-off impulse are important phenomena of the thermodynamic effects produced in material bombarded by electron beams. The experimental results of the blow-off impulse in an improved carbon fiber-reinforced phenolic material (referred to, in short, as C/ph) exposed to intense electron beams are presented. Used to generate electron beams, the “FLASH II” accelerator has energy fluences ranging from 150 to 350 J·cm⁻², and average energies of 0.5 or 0.6 MeV. The experimental results showed that the coupling coefficient of the blow-off impulse of C/ph was 0.42 ± 0.02 Pa∙s/(J·cm⁻²). The thermal shock waves and the blow-off impulse were numerically calculated separately by using a one-dimensional elastic–plastic hydrodynamic model. Attenuating with propagating distances, the peak values of the thermal shock waves during experiments were 0.6~1.5 GPa at the location of x = 8 mm in targets. The results of the numerical calculations were in good agreement with experimental data. The results obtained provide a basis for nuclear hardness and survivability assessments of aerospace. Full article

(This article belongs to the Special Issue Applications of Advanced Films and Materials in Space Microwave Technologies)

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