# Presentation: 143315

## Microwave Plasma Torch and its Application

***Soon Cheon Cho, Jong Hun Kim, and Han Sup Uhm***
*Department of Molecular Sciences and Technology,Ajou University, *
*San 5 Wonchon-Dong, Youngtong-Gu, Suwon 443-749, Korea. *

**CONCLUSION**

**Abstract**

*Ajou University                                                       Energy Physics research Laboratory*

- Y. C. Hong, S. C. Cho, C. U. Bang, D. H. Shin, J. H. Kim, H. S. Uhm, W. J. Yi,, Appl. Phys. Lett. 88, 201502 (2006)..
- C. U. Bang, Y. C. Hong, S. C. Cho, H. S. Uhm, and W. J. Yi, IEEE. Trans. Plasma Sci. 34, 1751 (2006).
- D. H. Shin, Y. C. Hong, S. C. Cho, and H.S. Uhm, , *Phys. Plasmas* 13, 114504 (2006).
- S. C. Cho, Y. C. Hong, and H. S. Uhm, Chem. Phys. Lett. 429, 214 (2006).
- Y. C. Hong, J. H. Kim, C. U. Bang, and H. S. Uhm, Phys. plasmas 12, 114501 (2005)
- Yong Cheol Honga and Han Sup Uhm, Appl. Phys. Lett. 88, 244101 (2006)

**REFERENCE**

**Methane**

**Kerosene**

** ****Theory**

**Fig.  Schematic Diagram of Electrodless Atmospheric Microwave Plasma Torch**

**Microwave Plasma Burner**

**  ****Advantages of Microwave Plasma Torch**
**  ****Electrodeless.**
**  ****Frequency: 2.45 GHz.**
**  ****High energy-efficiency: ~80%.**
**  ****Commercially applicable parts.**
**  ****Easy and simple operation.**
**  ****Easy scaling-up.**

**Fig.  Microwave Plasma torch.**

**Fig. 2. Atmospheric pressure, 1 kW, 2.45 GHz microwave discharges in (a) 10 lpm argon, (b) 1 lpm argon, (c) 10 lpm helium, (d) 10 lpm nitrogen, (e) 10 lpm air, and (f) 5 lpm nitrogen + 10 lpm helium.**

**Microwave Plasma Torch**

** ****Characteristics of microwave plasma torch**** **
** ****Plasma stabilization. **
** ****The higher the power, the larger the volume**
** ****Controllable volume and temperature by gas flow.**
** ****Argon plasma**
** ****Density: ~ 8  × 10****14**** cm****-3**
** ****Gas temperature: ~3500 K **
** ****Air plasma **
** ****Density: ~3 × 10****13 ****cm****-3**
** ****Gas temperature : ~ 6000 K**
** ****Nitrogen plasma**
** ****Density: ~4 × 1013 cm****-3**
** ****Gas temperature: 6300 K**
**  ****Production of chemically active plasma species.**

**Providing a very reactive, unusual environment**

**Fig.  Plasma burner made of microwave plasma and fuel-burning flame .**

** ****Plasma burner as a thermal source **

**Microwave Plasma Application. 1**

** ****Abatement of SF****6 ****and CF****4 ****using an enhanced kerosene microwave plasma burner**

**Fig. Plot of DRE *****vs***** N****2**** flow rates. **

**Fig.  Experimental set-up. **

** ****FTIR spectra illustrating abatement of SF****6**** and CF****4**** in terms of N****2**** flow rates by making use of a kerosene microwave plasma burner. 1.15 kg/h 0.3 gal/h kerosene was sprayed into the plasma torch flame stabilized by 40 lpm air at 1.4 kW plasma power. A mixture of 30 lpm O****2****, nitrogen gas, and 0.1 lpm CF****4**** SF****6**** were injected into the contaminant injector**

**Microwave Plasma Application. 2**

**Microwave Plasma Application. 3**

** ****Nanostructured Materials: CNT**

**  ****CNT synthesis**
**  ****Plasma + Gas-phase synthesis**
**On-line synthesis**
**High growth rate  **

**Fig.  Experimental set-up. 12.5 lpm Ar + 2.5 lpm N****2**** plasma. (a) SEM and (b) TEM images**

**Dependence of temperature in CNT synthesis process**

**Fig. .Growth rate along with T****f****. Inset pictures are Variation of D and G band in Raman spectrum along with T****f****.**

- Nanostructured Materials: N-Doped TiO2

** ****N-doped TiO****2 **
** ****Doping of N as a impurities**
** ****Band-gap narrowing**
** ****Activation by Visible Light**

**Sample ****A****: O****2**** 10 lpm (S) + N****2**** 1 lpm (A)**
**Sample ****B****: N****2**** 10 lpm (S) + O****2**** 1 lpm (A)**
**Sample ****C****: N****2**** 10 lpm (S) + O****2**** 0.8 lpm (A)**
**Sample ****D****: Pure TiO****2**** Powder**

**Identification of red-shift of N-doped TiO****2**

** ****T****he microwave plasma-torch can be applied in gas phase at atmospheric pressure, for which an expensive ****vacuum system is not necessary**
** ****This plasma source can be applied in the ****continuous process****, which makes mass production possible, **
** ****And involves a compact system allowing ready operation for various applications. **
** ****It is these advantages that make it suitable for ****economical and efficient mass production****.**
** ****The present method is promising not only for the synthesis of nanosized of these materials but also for the preparation of other materials of nanosize **

**Microwave plasma torch have a large circle of application.  **
**   ****(1) Microwave plasma burner can effectively eliminate perfluorocompounds emitted **
**         ****from the semiconductor industries.**
**   ****(2) Nanocrystalline nanoparticles are directly synthesized in an atmospheric microwave**
**         ****plasma-torch, using gas-phase precursors or granules as a source material.**
**   ****(3)  the production can be carried out in the continuous process, which makes mass**
**          ****production possible;**
**   ****(4)  the production system is compact, allowing ready operation for various applications. **

**"M****ethane-Augmented Microwave Plasma Burner****"****, **