Measurement of Electric Field Distribution along the Plasma Column in Microwave Jet Discharges at Atmospheric Pressure

Razzak, Md. Abdur; Takamura, S.; Tsujikawa, Takayuki; Shibata, Hideto; Hatakeyama, Yuto

doi:10.1585/pfr.4.047

Cited by 7 publications

(5 citation statements)

References 28 publications

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“…12͑a͒, is employed to obtain the plasma parameters of microwavesustained helium plasma jet at atmospheric pressure. [19][20][21] The nozzle, which is equipotential to the grounded waveguide, is used as the reference electrode for the probe. Figure 12͑b͒ shows the I-V characteristics of the probe at different height from the nozzle head.…”

Section: Analysis Of the Probe Characteristicsmentioning

confidence: 99%

Development of asymmetric double probe formula and its application for collisional plasmas

Saitô

Razzak

Takamura

et al. 2010

Journal of Applied Physics

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The ratio of the electron and ion saturation currents in single probe I-V characteristics for microwave-sustained plasma jets at atmospheric pressure are found to be much smaller than the value expected from the standard high-pressure single probe theory providing an over estimation of electron temperatures. By assuming that the single probe characteristic behaves as an asymmetric double probe when the electron to ion saturation current ratio is reduced, the whole characteristics may be fitted and significantly lower electron temperatures may be derived. In this study, asymmetric double probe theory for collisional plasmas is developed and employed to microwave-sustained helium plasma jets in order to estimate the plasma parameters (electron temperature and plasma density) at atmospheric pressure avoiding the overestimation of electron temperature.

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Section: Analysis Of the Probe Characteristicsmentioning

confidence: 99%

Development of asymmetric double probe formula and its application for collisional plasmas

Saitô

Razzak

Takamura

et al. 2010

Journal of Applied Physics

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“…Recently, the production of microwave plasma jets at atmospheric pressure [7][8][9] using the recently developed TIAGO (Torcheà Injection Axiale sur Guide d'Ondes, in French) nozzle [7] become very popular due to its simplicity, easy ignition, efficient microwave-to-plasma coupling, electrodeless operation, unnecessacity of vacuum chamber, availability of inexpensive sources at 2.45 GHz, and sustainment of the discharge at open air. However, to generate such stable and efficient plasmas using the TIAGO system, the discharge performance of the generated plasmas must be optimized by investigating the plasma parameters.…”

Section: Introductionmentioning

confidence: 99%

Estimation of Plasma Parameters for Microwave‐Sustained Ar/He Plasma Jets at Atmospheric Pressure

Razzak

Takamura

Saitô

et al. 2010

Contrib. Plasma Phys.

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In this article, we have analyzed the measured probe characteristics of microwave-sustained Ar and He plasma jets at atmospheric pressure using the high-pressure probe theory developed by Talukder et al. in order to determine the generated plasma parameters (electron temperature, Te, electron density, Ne, plasma potential, φp). The calculation shows some unusual temperature profiles (both axial and radial) as well as provides some over estimation of electron temperature measured from the distorted I-V characteristic due to a smaller electron to ion saturation current ratio coming from the limited electron saturation current. In order to overcome these limitations, the measured probe characteristics are also analyzed by using the asymmetric double probe theory developed by our group, which provides reasonable value of plasma parameters. The influence of microwave power and gas flow rate on the plasma parameters are also investigated.

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“…However, our goal was to test the behaviour of the torch in an ordinary laboratory and estimate the radiation losses under such conditions. In practice, these losses may depend on the design of the torch itself, such as the position of the diagonal wall of the tapered waveguide (on the nozzle side [11,48], on the reverse side [21,28] or on both sides [49]), additional setup elements (waveguide connections, tuning and measuring elements) and other laboratory objects, as well as the presence of laboratory personnel. It is almost impossible to take all these elements into account in numerical calculations.…”

Section: Methodsmentioning

confidence: 99%

Numerical and experimental analysis of radiation from a microwave plasma source of the TIAGO type

Nowakowska

Czylkowski

Hrycak

et al. 2021

Plasma Sources Sci. Technol.

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Unshielded microwave plasma sources radiate electromagnetic energy into space, which reduces the energy that can be used for plasma generation, contributes to discharge instability and is detrimental to laboratory personnel and equipment. We perform numerical analysis of radiation from a TIAGO torch, operating at 2.45 GHz, in which the plasma is generated at atmospheric pressure in the form of a flame at the tip of a metal nozzle. The analysis is carried out by solving the vector wave equation as for the antenna, with the assumption of axial symmetry and homogeneous electron density in the range of 1020–1022 m−3. We determine 2D electric field distributions inside a radiation sphere and radiation patterns for an unshielded torch and for a torch with shielding tubes with radii up to 100 mm and heights up to 200 mm. We also investigate the effect of the electron density, the tube height and radius on the reflected wave power, power absorbed in the plasma, radiated power and power entering the discharge. The results show that a tube of 25 mm radius (smaller than the cut-off radius) shields radiation very well, while the ratio of the radiated power to the entering power can achieve 85% for the unshielded torch and over 95% for a tube of 55 mm radius. In the experiment, we found that the powers required to ignite the discharge and to sustain it are about 80% greater and the plasma length is much shorter for a 55 mm radius tube than for a 25 mm radius tube, which we explain by the difference in the radiated power. The power density at a distance of 500 mm from the plasma with the entering power of 650 W depends on the direction and can exceed the permissible values several times. These results are consistent with calculations and indicate the need for appropriate shielding of the discharge.

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Measurement of Electric Field Distribution along the Plasma Column in Microwave Jet Discharges at Atmospheric Pressure

Cited by 7 publications

References 28 publications

Development of asymmetric double probe formula and its application for collisional plasmas

Development of asymmetric double probe formula and its application for collisional plasmas

Estimation of Plasma Parameters for Microwave‐Sustained Ar/He Plasma Jets at Atmospheric Pressure

Numerical and experimental analysis of radiation from a microwave plasma source of the TIAGO type

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