Operating modes of a magnetized direct-current discharge in helium

A high-pressure direct current magnetron discharge is analyzed using a self-consistent two-dimensional fluid model.  This discharge has potential interest in plasma switching applications due to its ability to generate rather dense (plasma density ~10¹⁹ m^-3) stable nonequilibrium plasmas at the pressures ~13.3 Pa (100 mTorr).  This discharge has several advantages over nanosecond pulsed high pressure discharges used in conventional plasma switchers since it operates at much lower voltages and lower gas pressures, with the advantage of much longer cathode lifetime.  In the present paper, we analyze the operating modes of this magnetron discharge for the conditions close to that of Sommerer et al., J. Phys. D: Appl. Phys. 52, 435202 (2019).  We observe the subnormal and normal modes of the magnetron operation whose physics differs from that typical for unmagnetized plasmas.