A newly designed ignition method for miniature radio frequency ion thruster

Area of Science:

• Aerospace Engineering
• Plasma Physics

Background:

• Micro-radio frequency (RF) ion thrusters often require high starting voltage and flow rates.
• These high initial parameters can lead to grid damage over extended operational periods.

Purpose of the Study:

• To develop and validate a novel ignition system for miniature RF ion thrusters.
• To decrease the ignition voltage and flow rate, thereby mitigating grid damage.

Main Methods:

• The proposed system integrates an intake pipe as a ground electrode, an inductance coil, and a pre-ionization chamber.
• It utilizes strong electric field breakdown and electromagnetic coupling for ignition.
• The system was tested on the Harbin Institute of Technology's RF Ion Thruster 4 (HRIT-4).

Main Results:

• Successful ignition was achieved at rated voltage and flow conditions.
• At a flow rate of 1.0 SCCM, the ignition voltage was below 1900 V.
• At a flow rate of 1.5 SCCM, the ignition voltage was below 1400 V.

Conclusions:

• The new ignition system effectively reduces startup voltage and flow rate for micro-RF ion thrusters.
• This system enhances thruster reliability by minimizing grid damage.
• The HRIT-4 demonstrated successful operation with the novel ignition approach.