scholarly journals A Linear Microwave Plasma Source Using a Circular Waveguide Filled with a Relatively High-Permittivity Dielectric: Comparison with a Conventional Quasi-Coaxial Line Waveguide

2021 ◽  
Vol 11 (12) ◽  
pp. 5358
Author(s):  
Ju-Hong Cha ◽  
Sang-Woo Kim ◽  
Ho-Jun Lee
Keyword(s):  
Electron Density ◽  
Microwave Plasma ◽  
Circular Waveguide ◽  
Coaxial Line ◽  
Plasma Source ◽  
Tangential Plane ◽  
High Permittivity ◽  
Deposition Area ◽  
Extended Plasma ◽  
Transverse Electromagnetic

For a conventional linear microwave plasma source (LMPS) with a quasi-coaxial line transverse electromagnetic (TEM) waveguide, a linearly extended plasma is sustained by the surface wave outside the tube. Due to the characteristics of the quasi-coaxial line MPS, it is easy to generate a uniform plasma with radially omnidirectional surfaces, but it is difficult to maximize the electron density in a curved selected region. For the purpose of concentrating the plasma density in the deposition area, a novel LMPS which is suitable for curved structure deposition has been developed and compared with the conventional LMPS. As the shape of a circular waveguide, it is filled with relatively high-permittivity dielectric instead of a quasi-coaxial line waveguide. Microwave power at 2.45 GHz is transferred to the plasma through the continuous cylindrical-slotted line antenna, and the radiated electric field in the radial direction is made almost parallel to the tangential plane of the window surface. This research includes the advanced 3D numerical analysis and compares the results with the experiment. It shows that the electron density in the deposition area is higher than that of the conventional quasi-coaxial line plasma MPS.

scholarly journals Langmuir Probe Diagnostics with Optical Emission Spectrometry (OES) for Coaxial Line Microwave Plasma

2020 ◽  
Vol 10 (22) ◽  
pp. 8117
Author(s):  
Chi Chen ◽  
Wenjie Fu ◽  
Chaoyang Zhang ◽  
Dun Lu ◽  
Meng Han ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Langmuir Probe ◽  
Microwave Plasma ◽  
Optical Emission ◽  
Coaxial Line ◽  
Plasma Source ◽  
Optical Emission Spectrometry ◽  
Emission Spectrometry ◽  
Plasma Parameters ◽  
Current Voltage

The Langmuir probe is a feasible method to measure plasma parameters. However, as the reaction progresses in the discharged plasma, the contamination would be attached to the probe surface and lead to a higher incorrect electron temperature. Then, the electron density cannot be obtained. This paper reports a simple approach to combining the Langmuir probe and the optical emission spectrometry (OES), which can be used to obtain the electron temperature to solve this problem. Even the Langmuir probe is contaminative, the probe current–voltage (I–V) curve with the OES spectra also gives the approximate electron temperature and density. A homemade coaxial line microwave plasma source driven by a 2.45 GHz magnetron was adopted to verify this mothed, and the electron temperature and density in different pressure (40–80 Pa) and microwave power (400–800 W) were measured to verify that it is feasible.

scholarly journals A New Stripline-Based Atmospheric Pressure Microwave Plasma Sheet Source Designed for Surface Modification of Materials

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7212
Author(s):  
Helena Nowakowska ◽  
Dariusz Czylkowski ◽  
Bartosz Hrycak ◽  
Mariusz Jasiński
Keyword(s):  
Surface Modification ◽  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Coaxial Line ◽  
Plasma Source ◽  
Power Flux ◽  
Power Characteristics ◽  
Radiated Power ◽  
New Type ◽  
The Difference

A new type of microwave plasma source is presented in which plasma at atmospheric pressure is generated inside a quartz rectangular flat box placed in a stripline supplied by a 2.45 GHz coaxial line. The plasma has a sheet shape and is designed for surface modification. Electric field and power flux distributions, tuning characteristics, and power characteristics (ratios of radiated, absorbed, and entering power) are numerically studied for three configurations: open, semi-closed, and closed. The calculations show that near-zero radiation reduction is possible only for the closed configuration, while the ratio of radiated power to entering power is always greater than 30% for the other configurations. The moving plunger is not sufficient for the ratio of reflected to incident power to fall below 20% for both the closed and open configurations. This is possible for the semi-closed configuration, but then the radiated power is the highest. The experiment shows that for the same entering power, the plasma volume is largest for the closed configuration and smallest for the open configuration, which we attribute to the difference in radiated power. The plasma generated using the closed stripline configuration has a larger volume than plasma generated using the rectangular waveguide.

Characteristics of 2.45GHz Microwave Plasma by Langmuir Probe Measurements

2007 ◽  
Vol 124-126 ◽  
pp. 1621-1624 ◽  
Author(s):  
Sun Yong Choi ◽  
Wataru Minami ◽  
Lae Hyun Kim ◽  
Hee Joon Kim
Keyword(s):  
Electron Temperature ◽  
Electron Density ◽  
Microwave Power ◽  
Langmuir Probe ◽  
Microwave Plasma ◽  
Debye Length ◽  
Plasma Source ◽  
Mean Free Path ◽  
High Energy ◽  
Langmuir Probe Measurements

The characteristics, such as electron temperature and the electron density, of CF4/Ar discharge in 2.45GHz microwave has been investigated by using a Langmuir probe with the microwave power and position. The results showed that the electron temperature and the electron density decrease with increasing distance from the plasma source. Increasing power enhances the dissociation and ionization of gas, and increases the electron densities. The electron temperature was decreased by reducing the mean free path of electrons with increasing microwave power. The electron temperature is 7.63 ~ 2.49 eV, and the electron density is 0.85×1011 ~ 4.3×1011 cm-3. From obtained electron energy distribution function, we known that high energy electron decreased with increasing microwave power and distance from the plasma source. The generated plasma by developed our system has good quality as results of Debye length λD = 35.8 ~ 67.3 μm, and Ln(ND) = 33.4 ~ 35.2.

scholarly journals Characterization of an Atmospheric-Pressure Argon Plasma Generated by 915 MHz Microwaves Using Optical Emission Spectroscopy

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Robert Miotk ◽  
Bartosz Hrycak ◽  
Mariusz Jasiński ◽  
Jerzy Mizeraczyk
Keyword(s):  
Atmospheric Pressure ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Microwave Plasma ◽  
Argon Plasma ◽  
Optical Emission ◽  
Coaxial Line ◽  
Plasma Source ◽  
Stark Broadening ◽  
Concentration Of Electrons

The paper presents the investigations of an atmospheric-pressure argon plasma generated at 915 MHz microwaves using the optical emission spectroscopy (OES). The 915 MHz microwave plasma was inducted and sustained in a waveguide-supplied coaxial-line-based nozzleless microwave plasma source. The aim of presented investigations was to estimate parameters of the generated plasma, that is, excitation temperature of electrons Texc, temperature of plasma gas Tg, and concentration of electrons ne. Assuming that excited levels of argon atoms are in local thermodynamic equilibrium, Boltzmann method allowed in determining the Texc temperature in the range of 8100–11000 K. The temperature of plasma gas Tg was estimated by comparing the simulated spectra of the OH radical to the measured one in LIFBASE program. The obtained Tg temperature ranged in 1200–2800 K. Using a method based on Stark broadening of the Hβ line, the concentration of electrons ne was determined in the range from 1.4 × 1015 to 1.7 × 1015 cm−3, depending on the power absorbed by the microwave plasma.

Simple low‐cost microwave plasma source

1986 ◽  
Vol 57 (2) ◽  
pp. 164-166 ◽  
Author(s):  
L. G. Meiners ◽  
D. B. Alford
Keyword(s):  
Microwave Plasma ◽  
Low Cost ◽  
Plasma Source

Numerical Analysis of Tuning Procedure of a Waveguide-Based Microwave Plasma Source

2011 ◽  
Vol 39 (11) ◽  
pp. 2906-2907 ◽  
Author(s):  
Helena Nowakowska ◽  
Mariusz Jasinski ◽  
Jerzy Mizeraczyk
Keyword(s):  
Numerical Analysis ◽  
Microwave Plasma ◽  
Plasma Source
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