Magnetized direct current microdischarge I. Effect of the gas pressure
Abstract
Following Paschen's law, electrical breakdown of gaps with small pd, where p is the gas pressure and d is the interelectrode gap, requires extremely high voltages. This means that the breakdown voltage for low-pressure microdischarges is of the order of a few kilovolts. This makes impractical the generation of low-pressure dc microdischarges. The application of dc magnetic field confines electrons in the cathode-anode gap. This leads to the significant decrease in the breakdown voltage because each electron experiences many collisions during its diffusion toward the anode. However, as was obtained experimentally, magnetized low-pressure microdischarges experience numerous instabilities whose nature is still not completely understood. In the present paper, we study the influence of the magnetic field on the low-pressure microdischarges. We use the self-consistent one-dimensional Particle-in-Cell Monte Carlo collisions model, which takes into account the electron magnetization while ions remain unmagnetized. We obtain striations in the discharge. We show that these striations appear in both homogeneous and non-homogeneous magnetic fields. We find simple expression for the instability growth rate, which shows that the instability results from ionization processes.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 03, 2017
- Source ID
- 10.1063/1.4977754
Entities
People
- Dmitry Levko
- Laxminarayan L. Raja
Organizations
- Air Force Office of Scientific Research
- University of Texas at Austin