A helicon plasma source for the Field-Reversed Configuration (FRC) plasma thruster is designed and developed to provide the initial plasma. A quartz tube chamber with 0.3 cm in thickness is used, which has a length of 55.5 cm and a diameter of 10 to 17 cm. Helicon plasma is produced at 13.56 MHz radio frequency (RF) power using a helical antenna with argon as the working gas. The diagnostic equipment includes homemade Langmuir three-probes, a professional camera and a current probe. The density peak in helicon plasma can be measured in this device at low axial magnetic fields of 0-120 Gs. Otherwise, the blue core appears in the center of the plasma when the magnetic field is above 1000 Gs and RF power is more than 1000 W.

Helicon plasma, low field density peak, coupling efficiency, blue core