Sputtered atom transport calculation via Radiosity View Factor Model and particle data compression. (April 2023)

• Record Type: Journal Article
• Authors: Araki, Samuel J.; Martin, Robert S.
• Is Part Of: Vacuum. Volume 210(2023)
• Publication Date: 2023-04
• Subjects: Electric propulsion -- Sputtering -- Sputter deposition -- Radiosity -- View factor model -- Free molecular flow; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2023.111867
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Sputter deposition calculation adds a major cost to a complete electric propulsion plume simulation due to the significantly lower velocities of sputtered atoms compared to plume ions. Simulation time is reduced considerably by decoupling the sputtered atom transport from the full plume simulation and solving sputter deposition via the non-Maxwellian Radiosity View Factor model. In order to do this, the incident ion or sputtered atom particle data are compressed on the fly and used in the subsequent simulation to construct the velocity distribution functions of the outgoing sputtered atoms in an interpolatable form. This paper explores several different methods enabling this approach and demonstrates the benefit in terms of accuracy, speed, and memory usage. Highlights: Reduced the computation time of a conventional EP plume simulation by over 95 percent. Achieved by separating the sputter deposition calculation from the plume simulation. Used a particle merging algorithm and the Radiosity View Factor model. Best to construct sputter atom VDF directly from incident ion particle data. Convergence of the method with surface mesh elements and VDF resolution.