Abstract:
In order to study the glow-like discharge in MHCD, we established a two-dimensional axis-symmetric fluid model, which consists of control equations, boundary conditions and chemical reactions under the conditions of air pressure of 100 Torr, the hollow radius of 100 μm and cathode voltage of-600 V and performed numerical simulation. The results show that in the mode of glow-like discharge, the discharge voltage is about-95 V. Near the hollow inner cathode appears a clear annular sheath structure and it extends to the flat cathode surface outside the hollow with the increase of the radial distance from the outer surface of the cathode. The density of charged particles number is about 10
19 m
-3, and the electron temperature in the cathode sheath and plasma region is about 10.2 eV and 1.5 eV. The results show that the peak values of ground-state and Penning ionization reaction rate are about 1.2×10~3 and 2.7×10~3 mol/(m~3·s), respectively. The overall net volume rate of electron generation is about 2.4 × 10
27 L/(m~3·s). Electrons are mainly produced in the hollow cathode region while a small amount are outside the cathode side hole and the sheath edge region.