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Wall conditioning coatings—lithium(Li), boron(B) and silicon(Si) —introduced by lithiumization, boronization, or siliconization, serve as a critical strategy for suppressing fuel recycling and reducing impurity fluxes from the wall of a tokamak. These techniques directly improve plasma initiation, reproducibility, energy confinement and operational stability in fusion devices. However, these coatings undergo both physical and chemical sputtering by boundary plasma bombardment. This erosion behavior critically determines coating lifetime and, consequently, long-pulse plasma performance. To evaluate the impact of physical sputtering on coating durability and to compare material-specific differences, we employ binary collision approximation (BCA) simulations to investigate the physical sputtering behavior of Li, B, and Si coatings. Carbon (C) and tungsten (W) substrates are also modeled to assess interface effects. The results reveal pronounced differences in the sputtering yields of Li, B, and Si across incident angles and deuterium energies. Owing to its low surface binding energy, lithium exhibits the highest sputtering yield at large angles and low energies; whereas silicon, with the highest atomic number, presents the highest sputtering yield at small angles and high energies. Sputtering yields of carbon-based and tungsten-based coatings vary with angle and energy, driven by differences in deuterium backscattering at the interface and substrate sputtering. Notably, for tungsten-based coatings, the sputtering yields increase dramatically at specific energies. This arises because, due to tungsten’s high surface binding energy, incident deuterium atoms are reflected at the tungsten interface and subsequently collide with coating elements. Consequently, when the energy transferred to the surface element is higher than its sputtering threshold, the sputtering yield increases. Additionally, increasing incident fluence modifies the target composition, leading to corresponding changes in the sputtering yields of coating materials. In summary, coating materials should be selected according to the expected angle- and energy-distribution of the incident plasma particles. To suppress the abrupt yield increase observed of tungsten substrates at specific energies, the coatings must be sufficiently thick. These findings provide a theoretical basis for selecting conditioning materials and optimizing wall conditioning strategies in fusion devices.
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[1] Zhu Y K 2010 Vacuum Science and technology in Nuclear Engineering (Beijing: Atomic Energy Press) pp160-177(in Chinese) [朱毓坤2010 核真空科学技术(北京：原子能出版社) 第160-177页].
[2] Pitts R A, Loarte A, Wauters T, Dubrov M, Gribov Y, Köchl F, Pshenov A, Zhang Y, Artola J, Bonnin X, Chen L, Lehnen M, Schmid K, Ding R, Frerichs H, Futtersack R, Gong X, Hagelaar G, Hodille E, Hobirk J, Krat S, Matveev D, Paschalidis K, Qian J, Ratynskaia S, Rizzi T, Rozhansky V, Tamain P, Tolias P, Zhang L, Zhang W 2025 Nucl. Mater. Energy 42 101854
[3] Winter J 1996 Plasma Phys. Control. Fusion 38(6) 1503
[4] Kaita R 2019 Plasma Phys. Control. Fusion 61 113001
[5] Skinner C H, Allain J P, Bell M G, Friesen F Q L, Heim B, Jaworski M A, Kugel H, Maingi R, Rais B, Taylor C N 2011 Phys. Scr. T145 014020
[6] Sun Z, Maingi R, Hu J S, Xu W, Zuo G Z, Yu Y W, Wu C R, Huang M, Meng X C, Zhang L, Wang L, Mao S T, Ding F, Mansfield D K, Canik J, Lunsford R, Bortolon A, Gong X Z 2019 Nucl. Mater. Energy 19 124
[7] Cheng Y X, Zhang L,Hu A L,Shigeru Morita S, Zhang W M, Zhou C X, Mitnik D, Zhang F L, Ma J Y, Li Z W, Cao Y M, Liu H Q 2024 Nucl. Mater. Energy 41 101744
[8] Rohde V, Balden M, Krieger K, Neu R, ASDEX Upgrade Team 2025, Nucl. Mater. Energy 43 101923
[9] Masuzaki S, Shoji M, Nespoli F, Lunsford R, Motojima G, Yajima M, Tokitani M, Oishi T, Kawate T, Goto M 2025 Nucl. Mater. Energy 42 101843
[10] Samm U, Bogen P, Esser G, Hey J D, Hintz E, Huber A, Könen L, Lie Y T, Mertens P, Philipps V,Pospieszcyk A, Rusbüldt D, Seggern J, Schorn R P, Schweer B, Tokar' M, Unterberg B, Vietzke E, Wienhold P, Winter J 1995 J. Nucl. Mater. 220 25
[11] Duan X R, Cao Z, Cui C H, Cai X, Sun H H, Ding X T, Pan Y D, Wang M X, Yang Q W, Song X M, HL-2A Team 2007 J. Nucl. Mater. 363-365 1340
[12] Effenberg F, Abe S, Sinclair G, Abrams T, Bortolon A, Wampler W R, Laggner F M, Rudakov D L, Bykov I, Lasnier C J, Mauzey D, Nagy A, Nazikian R, Scotti F, Wang H Q, Wilcox R S, the DIII-D Team 2023 Nucl. Fusion 63 106004
[13] Xu W, Hu J, Sun Z, Maingi R, Zhang L, Yu Y W, Li C L, Zuo G Z, Qian Y Z, Huang M, Meng X C, Gao W, Duan Y M, Chen Y J, Wang K, Lin X D, Gao X 2020 Plasma Phys. Control. Fusion 62 085012
[14] Sereda S, Brezinsek S, Wang E, Barbui T, Brakel R, Buttenschön B, Goriaev A, U. Hergenhahn, Höfel U, Jakubowski M, Knieps A, König R, Krychowiak M, Kwak S, Liang Y, Naujoks D, Pavone A, Rasinski M, Rudischhauser L, Ślęczka M, Svensson J, Viebke H, Wauters T, Wei Y, Winters V, Zhang D, the W7-X team 2020 Nucl. Fusion 60 086007
[15] Dibon M, Rohde V, Stelzer F, Hegele K, Uhlmann M, ASDEX Upgrade Team 2012 Fusion Eng. Des. 165 112233
[16] Tramontin L, Antoni V, Bagatin M, Boscarino D, Cattaruzza E, Rigato V, Zandolin S 1999 J. Nucl. Mater. 266–269 709
[17] Miyagawa Y, Nakadate H, Djurabekova F, Miyagawa S, Surf. Coat. Technol. 158–159 87
[18] Miyagawa Y, Miyagawa S 1983 J. Appl. Phys. 54 7124.
[19] Miyagawa Y, Ikeyama M, Saito K, Massouras G, Miyagawa S 1991 J. Appl. Phys. 70 7289
[20] Shao Q Y, Huo Y K, Chen J X, Wu S M, Pan Z Y 1991 Acta Phys. Sin. 40(4) 659 (in Chinese)[邵其鋆, 霍裕昆, 陈建新, 吴士明, 潘正瑛. 1991物理学报 40(4) 659]
[21] Lu F 2022 Technology and Application of Vacuum Coating(Beijing: Chemical Industry Press) pp149-153(in Chinese)[陆峰 2022 真空镀膜技术与应用(北京：化学工业出版社)第149-153页].
[22] Shao Q Y, Pan Z Y 1995 Acta Phys. Sin. 1995 44(3) 479(in Chinese)[邵其鋆, 潘正瑛. 1995. 物理学报44(3) 479]
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