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The properties of an inductive RF discharge placed in a longitudinal external magnetic field with an induction of less than 70 G at frequencies of 2, 4, and 13.56 MHz are studied. The dependences of the region of existence of the discharge, the efficiency of the RF power input and the structure of the RF magnetic field on the external magnetic field induction are studied experimentally. The experimental results are compared with calculations based on a previously developed electromagnetic discharge model. It is shown that the local maximum of the plasma density observed at weak magnetic fields is associated with the resonant excitation of waves in the plasma source. The excited wave is close to a transverse helicon at a frequency of 2 MHz, and its properties approach the Trivelpiece–Gould wave at a frequency of 13.56 MHz,. [ABSTRACT FROM AUTHOR]

The results of an experimental study of a low-power RF plasma source placed in a longitudinal magnetic field (helicon thruster), when it operates on a capacitive RF discharge and inductive RF discharges with a capacitive component, are presented. A significant dependence of the characteristics of the ion and electron fluxes of the source on the induction of a constant magnetic field is shown. The fundamental applicability of capacitive RF discharge as a working process in the studied plasma source is demonstrated. It is shown that the increase in the average energy of ions in the flow at the outlet of the source with the appearance of the capacitive component of the discharge is slight. [ABSTRACT FROM AUTHOR]

The paper presents the results of an experimental study of the axial structure of the longitudinal RF magnetic field and parameters of the plasma of an inductive low-power plasma source placed in a magnetic field of 12–72 G. It is shown that, already in a magnetic field of 24 G, a nonmonotonic dependence of the longitudinal component of the RF magnetic field on the axial coordinate is clearly manifested. The change in the phase of the RF field indicates that a partially traveling wave is formed in the discharge. Probe measurements show that the electron energy distribution function is enriched with fast electrons whose velocity correlates with the phase velocity of the wave. [ABSTRACT FROM AUTHOR]

The paper presents the results of an experimental study of a low-power RF inductive plasma source placed in a longitudinal magnetic field. The measurements show the formation of an ion-accelerating potential drop at the source output with its value depending on the magnetic field and the flow rate of the working gas. The parameters of the electron and ion flows generated by the source nonmonotonically change with the magnetic field. In the main range of the studied magnetic fields, the electron flux generated by the source at the axis of the system exceeds the ion flux, and the average electron energy increases with the magnetic field. [ABSTRACT FROM AUTHOR]