Study on the anisotropy of the secondary electron yield and resistance of the laser-etched copper

Zhang, Wenli; Wang, Yigang; Wang, Sihui; Lu, Fan; Wei, Wei; Fang, Jianwei; Liu, Weimin; Wang, Yong

doi:10.1016/j.apsusc.2021.150419

Cited by 5 publications

(3 citation statements)

References 36 publications

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“…So far, B in every existing formulae for SEE from a given emitter has been treated as a constant. [8,29,34,55,56] From the above analysis, and the fact that all the experimental δ values for NEASLDs which we can find agree well with corresponding values calculated by the method presented here, we can conclude that δ of NEASLDs calculated using Eqs. ( 21) and ( 22) agree well with the experimental results.…”

Section: Resultssupporting

confidence: 85%

Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

Xie¹,

Dong²,

Liu³

2023

Chinese Phys. B

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The formulas for parameters of negative electron affinity semiconductor NEAS with large λ NEASLD are deduced, respectively, λ is the mean escape depth of secondary electrons; And the methods of obtaining parameters such as λ, B, E pom, maximum δ and δ at 100.0 keV≥E po≥1.0 keV of NEASLD with the deduced formulas are presented, respectively, where B is the probability that an internal secondary electron escapes into vacuum upon reaching the emission surface of emitter, δ is secondary electron yield, E po is incident energy of primary electron, E pom is the E po corresponding to maximum δ. The parameters obtained here were analyzed, it can be concluded that several parameters of NEASLD obtained by the methods presented here agree with those obtained by other authors. The relation between secondary electron emission and photo-emission from NEAS with large mean escape depth of excited electrons is investigated, it concludes that the presented method of obtaining λ is a more accurate method of obtaining corresponding parameter of NEAS with large λph, and that the presented method of calculating B at E po > 10.0 keV is a more widely applicable method of obtaining corresponding parameter of NEAS with large λph, λph is the mean escape depth of photo-electrons.

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Section: Resultssupporting

confidence: 85%

Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

Xie¹,

Dong²,

Liu³

2023

Chinese Phys. B

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“…The melting and splashing of the copper during the laser-etching process lead to the appearance of the grooves, plateaus and spherical structures, which undulate the surface topography of the OFC, as illustrated in figure 1. The previous studies have proven that the geometries of the grooves and plateaus are highly correlated with the etching parameters [18,29,30], the average depth of the grooves (before DC magnetron sputtering) is about 58 μm corresponding to the etching parameters in this study, as measured from the cross-sectional image of sample B displayed in figure 6(a). The unevenness of the laser-etched surface results the selective growth of the thin film, i.e., the film tends to grow on the flat areas (i.e., the plateaus and the surrounding spherical structures), and the target atoms deposit relatively few on the groove walls.…”

Section: Discussionsupporting

confidence: 66%

Surface characterization and secondary electron yield measurement of the Ti-Zr-V films deposited on laser-etched copper

Zhang¹,

Zhu²,

Wang³

et al. 2022

J. Inst.

Self Cite

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The electron multipacting effect and distributed vacuum profile, induced by the interaction of the particles in vacuum chamber with the surrounding walls, are the significant issues in modern accelerators. Laser-etching the inner surface of the vacuum chambers can effectively eliminate the electron multipacting effect, and depositing the non-evaporable getter (NEG) film on the vacuum chamber walls can provide distributed pumping properties. In the present study, Ti-Zr-V NEG films were prepared by magnetron sputtering technique on laser-etched oxygen-free copper (OFC) with different deposition times. The secondary electron yields (SEY), activation kinetics, and resistance of the samples were evaluated. The results show that although the SEYs of the coated laser-etched samples are higher than those of the uncoated laser-etched sample, the maximum SEY values are still below the threshold of the operation requirements. The Ti-Zr-V film deposited on laser-etched surface exhibits obvious nucleation phenomenon with columnar microstructure and can be activated at 180^∘C. Moreover, the coated laser-etched samples present lower resistance compared with the uncoated laser-etched sample. The combination of the laser-etching technique and the NEG thin film is aim to provide a practical treatment for the vacuum chambers in modern accelerators.

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“…The suppression method is usually adopted with surface treatment to reduce the SEY. For example, the surface of the material was treated with irradiation to reduce the SEY [10,11], and the roughness of the material surface was enhanced with etching [12,13]. The larger roughness can bind the incident electrons to reduce the SEY of the material.…”

Section: Introductionmentioning

confidence: 99%

Modelling the Impact of Graphene Coating of Different Thicknesses on Polyimide Substrate on the Secondary Electron Yield

Qi,

Ma,

Liu

et al. 2023

Coatings

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Polyimide material is widely used in the aerospace field, but its secondary electron emission yield is high. In this study, a graphene coating was used to suppress its secondary electron emission, and the secondary electron emission yield of graphene-coated materials with different thicknesses was calculated using the GEANT4 numerical simulation method. The suppression effect of different thicknesses of graphene coatings on the secondary electron emission was analyzed. The simulation results showed that the optimal graphene coating thicknesses for the lowest secondary electron yield of polyimide materials were 1 nm and 5 nm, which reduced the secondary electron emission yield by 13% in terms of simulation. The 5 nm graphene coating reduced the secondary electron emission yield by 6% compared to the polyimide material from an experimental perspective. The 5 nm coating showed better results at higher energies and was experimentally verified by preparing five layers of graphene coating, which showed good agreement between the simulation and experiment. Meanwhile, with the increase in graphene coating thickness, the surface secondary electron emission displacement range decreased, and the secondary electrons produced at the surface were of low energy. The results of this study can provide technical reference for polyimide in aerospace applications and secondary electron emission simulation.

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Study on the anisotropy of the secondary electron yield and resistance of the laser-etched copper

Cited by 5 publications

References 36 publications

Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

Surface characterization and secondary electron yield measurement of the Ti-Zr-V films deposited on laser-etched copper

Modelling the Impact of Graphene Coating of Different Thicknesses on Polyimide Substrate on the Secondary Electron Yield

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