Comparison of dust charging between orbital-motion-limited theory and particle-in-cell simulations

Journal Article · Wed Nov 18 00:00:00 EST 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4935697· OSTI ID:1457245

Delzanno, Gian Luca ^[1]; Tang, Xian-Zhu ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

The Orbital-Motion-Limited (OML) theory has been modified to predict the dust charge and the results were contrasted with the Whipple approximation [X. Z. Tang and G. L. Delzanno, Phys. Plasmas 21, 123708 (2014)]. To further establish its regime of applicability, here, the OML predictions (for a non-electron-emitting, spherical dust grain at rest in a collisionless, unmagnetized plasma) are compared with particle-in-cell simulations that retain the absorption radius effect. It is found that for large dust grain radius r_d relative to the plasma Debye length λ_D, the revised OML theory remains a very good approximation as, for the parameters considered (r_d/λ_D ≤ 10, equal electron and ion temperatures), it yields the dust charge to within 20% accuracy. This is a substantial improvement over the Whipple approximation. The dust collected currents and energy fluxes, which remain the same in the revised and standard OML theories, are accurate to within 15%–30%.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Fusion Energy Sciences (FES); USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1457245
• Alternate ID(s): OSTI ID: 1226393
• Report Number(s): LA-UR-15-24364; PHPAEN; TRN: US1901328
• Journal Information: Physics of Plasmas, Vol. 22, Issue 11; ISSN 1070-664X
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Maxwell equations
charged currents
interplanetary dust
plasma diagnostics
plasma sheaths
Poisson's equation
plasma density
plasma temperature
electric fields
particle-in-cell method