TY - GEN
T1 - A New Self-Consistent Boundary Condition for Modeling of Plasma Plume Evolution Using a Fully Kinetic Pic Approach
AU - Jambunathan, Revathi
AU - Levin, Deborah
N1 - Publisher Copyright:
© 2018 IEEE.
PY - 2018/6/24
Y1 - 2018/6/24
N2 - Plasma plume expansion is commonly observed in many applications, such as, ion thruster plumes, astrophysical jets, as well as plasma accelerators. Typically, electrons are treated as a fluid for such simulations, however, in our recent1 kinetic treatment of electrons we have shown that the electron velocity distribution in an expanding plume is anisotropic. In particular, we found that when the electron source is shifted compared to the ion beam, as is observed in realistic ion engine configurations, holes develop in the electron phase-space within 3,000 electron plasma periods, i.e., 3,000omega-{text{pe}} {-1}. This bi-modal electron velocity distribution is known to trigger a two-stream instability, and affect the ion dynamics. The times-scale over which the ion dynamics2 is affected is typically 40omega-{text{pi}}{-1} or 12,000omega-{text{pe}} {-1}. A major issue in modeling electrons kinetically is that, when electrons exit the domain, a virtual anode is developed, leading to non-physical effects. To work around this problem, the kinetic plasma plume simulations are terminated before the leading-edge of the plume, called the beam-front, crosses the boundary thereby avoiding boundary-effects. However, important physics, such as, ion beam neutralization as well as the effect of bi-modal electron velocity distribution on the ion beam evolution require long simulations times.
AB - Plasma plume expansion is commonly observed in many applications, such as, ion thruster plumes, astrophysical jets, as well as plasma accelerators. Typically, electrons are treated as a fluid for such simulations, however, in our recent1 kinetic treatment of electrons we have shown that the electron velocity distribution in an expanding plume is anisotropic. In particular, we found that when the electron source is shifted compared to the ion beam, as is observed in realistic ion engine configurations, holes develop in the electron phase-space within 3,000 electron plasma periods, i.e., 3,000omega-{text{pe}} {-1}. This bi-modal electron velocity distribution is known to trigger a two-stream instability, and affect the ion dynamics. The times-scale over which the ion dynamics2 is affected is typically 40omega-{text{pi}}{-1} or 12,000omega-{text{pe}} {-1}. A major issue in modeling electrons kinetically is that, when electrons exit the domain, a virtual anode is developed, leading to non-physical effects. To work around this problem, the kinetic plasma plume simulations are terminated before the leading-edge of the plume, called the beam-front, crosses the boundary thereby avoiding boundary-effects. However, important physics, such as, ion beam neutralization as well as the effect of bi-modal electron velocity distribution on the ion beam evolution require long simulations times.
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U2 - 10.1109/ICOPS35962.2018.9575757
DO - 10.1109/ICOPS35962.2018.9575757
M3 - Conference contribution
AN - SCOPUS:85118928151
T3 - IEEE International Conference on Plasma Science
BT - ICOPS 2018 - 45th IEEE International Conference on Plasma Science
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 45th IEEE International Conference on Plasma Science, ICOPS 2018
Y2 - 24 June 2018 through 28 June 2018
ER -