Numerical Analysis of Neutral Entrainment Effect on Field-Reversed Configuration Thruster Efficiency
Abstract
The collisional processes between ions and electrons of a field-reversed plasmoid traveling at high speed and neutral gas particles, entrained by the plasmoid, are examined in an adiabatic bath relaxation. The importance of different reaction mechanisms, such as charge exchange, electron impact ionization, and electronic excitation with metastable atom formation and radiation, is analyzed for conditions typical for field-reversed configuration thrusters. The flow conditions include neon gas and plasma with densities on the order of 1018 molecule/m3, plasma temperatures between 5 and 10 eV, and relative plasma-neutral velocities up to 30 km/s. Then, an implicit particle-in-cell code, Celeste3D, extended to include all relevant plasma-neutral and neutral-neutral elastic and inelastic processes and Coulomb collisions, is applied to study the neutral entrainment. The model includes a planar flow between a field reversed configuration plasmoid initially at a Schmid-Burgk equilibrium and neutral gas with varying relative velocities, plasma temperatures, and neutral gas densities. The contribution of charge exchange, electron impact ionization reactions, and collisional radiation is analyzed, and the sensitivity of the entrainment efficiency to the plasmoid translation velocity and neutral density is evaluated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2014
- Accession Number
- ADA626299
Entities
People
- Jean Luc Cambier
- Jeremiah Brackbill
- Natalia E. Gimelshein
- Sergey F. Gimelshein
Organizations
- Air Force Research Laboratory