Microwave-Frequency Effects on Microplasma

Microplasma thruster powered by X-band microwaves

“…X-band microwaves have been employed to generate highdensity, high-temperature plasmas under electron cyclotron resonance conditions at low pressures (∼10 −5 -10 −4 Pa) for use of highly charged ion and short wavelength radiation sources; [72][73][74] and a few studies have been concerned with plasma discharges at higher and atmospheric pressures (∼1-50 kPa) where the plasma is highly collisional. 75 Microwave frequency effects on plasma discharges have recently attracted much attention to generate higher density nonthermal microplasmas at atmospheric pressures, [76][77][78][79][80] from the viewpoint of a fundamental interest in plasma physics/ chemistry as well as their applications such as materials FIG. 1.…”

Electron and ion kinetics in three-dimensional confined microwave-induced microplasmas at low gas pressures

“…This tendency agrees well with the finding that electron production was increased in microplasmas driven at higher microwave frequencies, as report by Xue and Hopwood. 3 As shown in Figure 18, at p g of 800 Pa, the γ-mode plasma was always observed in the frequency range from 2.15 to 2.75 GHz.…”

“…Thus far, most studies on simulating microplasma are based on fluid models 3,[28][29][30][31] and use efficient computation. The collective plasma characteristics are predicted using fluid models.…”

“…1 For d exceeding approximately 30 µm, the classical pd scaling laws (where p is the gas pressure) are valid even at gas pressures above one atmosphere. This resulted in most microplasma sources operating at a relatively high gas pressure (hundreds of Torr and above), [2][3][4] which has a wide variety of applications at near atmospheric pressures. [5][6][7][8][9] In addition to microplasmas operating at a relatively high gas pressure, there are many applications that use microplasma sources at low pressures (hundreds of Pascals or less).…”

Self-consistent fluid modeling and simulation on a pulsed microwave atmospheric-pressure argon plasma jet

“…17 To pay attention on microwave-driven plasma devices, many researches have focused on optimizing the device structure, in order to acquire special plasma composition, plasma size, and more efficient energy absorbed by plasmas. [18][19][20][21][22] Our previous works have proposed some types of microwave-driven plasma devices excited by surface waves of surface plasmon polaritons (SPPs). [23][24][25][26][27][28] At the interface between a metal (or overdense plasma) and a dielectric material, the surface wave of SPPs is excited as a special electromagnetic (EM) wave.…”