Kinetic behaviors of secondary electrons in magnetized capacitively coupled argon plasmas*

Magnetically enhanced capacitively coupled radio frequency plasma discharges (MECCPs) are widely used in various industrial applications. In the absence of a magnetic field, the secondary electrons (SEs) emitted from the electrodes can obtain the full sheath potential and exhibit significant nonlocal kinetics at low pressure. Whereas, with the introduction of the transverse magnetic field, SEs can be localized near the sheath and interact with the electric field inside the sheath for multiple times due to the strong magnetic confinement effect. Meanwhile, an interesting phenomena "branches" can be observed in the electron energy probability distributions (EEPFs) and spatiotemporal electron density. In this work, the secondary electrons kinetics and "branches" are investigated by a combination of 1d3v Particle-In-Cell/Monte Carlo Collision simulations and testing particle method, in MECCPs. The analysis of the SEs trajectories indicates that the "branches" observed in EEPFs and spatiotemporal total electron density, are direct results of the collective motion of SEs emitted at different radio frequency phases, and the number of the branches are related to the applied magnetic field strength. *This work was financially supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 11935005, 12105035), the Fundamental Research Funds for the Central Universities (No. DUT21TD104)