Pre-Ionization Plasma in a FRC Test Article


Pulsed plasma systems, specifically field reversed configuration devices, show great potential for future space propulsion systems. The fundamental formation process of heavygas plasma necessary for propulsion application is not well understood. The following study is focused on characterizing the pre-ionization stage of a field reversed configuration test article. Specifically, flux loop and B-dot probe data are presented and used calculate the magnetic flux and magnetic field strengths within MPX. Finally, plasma images collected with a high speed camera are presented. Tests are conducted at 15 and 20 kV using both air and argon over a pressure range of 2 - 70 mTorr and at atmosphere. Discharges with no plasma present have a frequency of 464 kHz while a discharge that produces plasma resonates at approximately 490 kHz. Details of probe construction and calibration are also presented. A maximum magnetic field of 882 G is observed for a 20 kV discharge with fill pressure of 45 mTorr of air near the edge of the theta coil. A maximum magnetic flux of 2.17 mWb is observed for a 20 kV discharge with a fill pressure of eight mTorr. The largest amount of energy absorbed by the plasma is 30.3 J and occurs during a 20 kV discharge in air at 60 mTorr. Peak magnetic fields, magnetic flux, and formation times as functions of gas species, pressure, and voltage are also presented. Maximum energy absorption into plasma occurs at 65 mTorr of air at a discharge voltage of 20 kV.

Meeting Name

50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition


Mechanical and Aerospace Engineering

Keywords and Phrases

B-Dot Probe; Discharge Voltages; Field Reversed Configurations; Fill Pressure; Flux-Loops; Formation Process; Formation Time; Gas Species; Magnetic Field Strengths; Plasma Images; Pre-Ionization; Pressure Ranges; Probe Construction; Propulsion Applications; Pulsed Plasma Systems; Space Propulsion System

Document Type

Article - Conference proceedings

Document Version


File Type





© 2012 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.

Publication Date

01 Jan 2012