Radio-frequency capacitively coupled plasma parameters evolution as a function of magnetic field strength

The use of magnetic fields in low-temperature plasma physics is promising in numerous applications. The magnetic field acts on the kinetic of the plasma charged particles, drastically modifying the ion and electron trajectories in the plasma. The influence of the magnetic field strength on plasma parameters, like the plasma and the electrode potentials, was measured for different gases and pressures, evidencing a strong variation before saturating for high magnetic fields. The saturation is connected to the variation of the ions and electrons collection area. It occurred when the magnetic field influence overcame the collisional effect, i.e. when the Larmor radius of ions became smaller than the ion mean free path. The electrostatic probe’s floating potential saturation was a marker of ion magnetisation. Varying the pressure enabled collision cross-section calculation for magnetised discharges. The estimated values in this contribution were consistent with the literature. Finally, the probe developed in this contribution allows for the quasi-independent measurement of perpendicular and parallel flux. • A Twin probe was developed to characterise the plasma perpendicularly and parallelly to the B field. • The floating potential of the radial probe indicated the magnetisation of the ions. • The electrode self-bias and plasma potential increase before saturating with the magnetic field. • That saturation depends on the pressure and the confinement of the plasma.