Modeling of the plasma jet of a stationary plasma thruster

Abstract

Numerical investigation and modeling of stationary plasma thruster low frequency oscillationsWe have developed a two-dimensional hybrid fluid -particle-in-cell Monte Carlo collisions ͑PIC-MCC͒ model to study the plume of a stationary plasma thruster. The model is based on a fluid description of the electrons ͑the electron density follows a Boltzmann distribution͒ and a particle description of the ion and neutral transport. Collisions between heavy species are taken into account with a Monte Carlo method. The electric field is obtained from Poisson's equation or from the quasineutrality assumption. We first show that the results from the PIC-MCC model are close to the results of a more time-consuming direct simulation Monte Carlo approach. We then compare the model predictions of the plume density and ion energy distribution with experimental measurements. Finally, we present a brief discussion on the assumptions of the model and on its ability to give reliable predictions on important issues such as the flux of ions backscattered to the satellite.

Numerical Study on Acceleration and Deceleration Mechanism of Weakly Ionized Plasma Flowing Supersonically Through Open Field Line

“…Since we treat just the exhausted plume of an arc plasma jet far downstream (∼30 cm) from the discharge region [10], [11], we assume the electron flux is the same as that of the ions at anywhere and at anytime. That is n e v e = n i v i (20) and (19) leads to the same velocity…”

“…On the other hand, now we discretize the domain with the size larger than the Debye length. Therefore, (19) must be satisfied at any cell, and hence, (33) becomes valid. Because of this relationship, the second order of Δ exactly vanishes in (31).…”

“…This indicates that the electron density is the same as the ion density throughout the domain calculated. Namely, the relationship n e = n i (19) holds anywhere at any time [29]. Hence, we do not need to solve the equation of continuity.…”

“…In the numerical procedure shown in Fig. 2, the only unknown quantity in (23) is E, since the electron density n e is given by (19), the velocity v e is given by (21), the temperature T e is given by (22), and the magnetic field B is given by (3)-(5). The collision frequency ν en is calculated from the collision cross section of helium with electron [33] as a function of thermal velocity of electron, v th e , which is easily calculated from T e , since the velocity of neutral particle is almost negligible at their collisions.…”

Approximate semi-analytical solutions for the steady-state expansion of a contactor plasma

“…Therefore, numerical simulations are usually constrained to either the near-or the far-field expansion, i.e. to a restricted simulation domain [12][13][14][15][16][17][18].…”