Advance on non-equilibrium plasma jets

Transcription

1 Advance on non-equilibrium plasma jets XinPei Lu College of EEE, HUST

2 Outline Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 2

3 Overview of the status of Cold Plasma Jets RF Hicks group, 1998 Plasma Sources Sci. Technol Gas temperature can be as low as tens of Celsius degree. The risk of arcing exists. E Stoffels, et al 2003 J. Phys. D: Appl. Phys Gas temperature is sensitive to the distance from the needle tip. It can be at room temperature. 3

4 Stonies R, et al Plasma Sources Sci. Technol Gas temperature is quite high. It can be touched by a finger for few seconds. Teschke M, et al 2005 IEEE Trans Plasma Sci. 33, The jet consumes power of about 4 W at peak voltage of 7 kv and frequency of 13 khz The jet looks continuously by bare eye is actually travels like a bullet with a velocity of 15 km/s 4

5 Laroussi M and Lu X 2005 Appl. Phys. Lett Hong Y C, et al 2006 Appl. Phys. Lett The plasma is driven by pulsed DC voltage. It can have a length of about 5cm. When N 2 is flow from the back and a 20 khz high voltage is applied between the two electrodes, a plasma jet up to 6.5 cm is generated in the surrounding air Diameter of the hole is about 500µm. 5

6 C. Jiang, et al 2009 Plasma Processes and Polymers. 6 H. Kim, et al Appl. Phys. Lett. 95, Driven by pulsed DC high voltage, pulse frequency: 1 khz; amplitude 6 kv. Applied voltage khz; V pp is less than 600 V; working gas Ar. 6

7 Q. Nie, et al 2008 Appl. Phys. Lett. 93, Applied voltage 48 khz; working gas Ar. 2.7kV 4kV 5kV 5.6kV X. Zhang, et al Appl. Phys. Lett. 93, Ar is fed through the side arm of the tube, and O 2 is injected into the end of quartz tube through the inner electrode to react with Ar plasma. Electron attachment inside the tube is weakened. 7

8 H. Lee, et al 2010 Plasma Processes & Polylers 7, 274 T. Ni, et al Appl. Phys. Lett. 92, Applied voltage 20 khz; working gas Helium. The plasma jet was used in combination with H 2 O 2 to remove stains from teeth stained by either coffee or red wine. Applied voltage 1 khz; working gas N 2 8

9 J. Kolb, et al Appl. Phys. Lett. 92, DC voltage; working gas Air. Y. Hong, et al Phys. Plasmas, 16, Applied voltage 60 Hz; working gas Air. 9

10 Leveille V, et al. Plasma Sources Sci. Technol (2005) Lai W, et al. Phys. of Plasmas (2005) Forster S, et al. Surface & Coatings Technol (2005) Xu L, et al. Thin Solid Films (2006) Chen G, et al. Plasma Sources Sci. Technol (2006) Walsh J L, et al. Appl. Phys. Lett (2006) Kim D, et al. Appl. Phys. Lett., (2007) Lu X, et al. Appl. Phys. Lett (2008) Lu X. et al. Appl. Phys. Lett (2008) Sands B, et al. Appl. Phys. Lett., (2008) Y. Hong, H. Uhm, W. Yi, Appl. Phys. Lett. 93, (2008) J. Walsh and M. Kong, Appl. Phys. Lett. 93, (2008) Shashurin, et al. Appl. Phys. Lett. 93, (2008) 10

11 J. Kim, et al. Appl. Phys. Lett. 93, (2008) S. Kim, et al. Appl. Phys. Lett. 94, (2009) W. Zhu, Q. Li, X. Zhu, and Y. Pu, J. Phys. D 42, (2009) N. Jiang, A. Ji, and Z. Cao, J. Appl. Phys. 106, (2009) Lu X, et al. IEEE Trans. Plasma Sci. 37, 668 (2009) J. Choi, et al. Plasma Process. Polym. 7, 258 (2010) G. Daeschlei, et al. Plasma Process. Polym. 7, 224 (2010) Shashurin, et al. Appl. Phys. Lett. 94, (2009) S. Deng, et al. Current Appl. Phys. 10, 1164 (2010) Q. Li, X. Zhu, J. Li, Y. Pu, J. Appl. Phys. 107, (2010) M. Qian, et al. J. Appl. Phys. 107, (2010) S. Kim, et al. Phys. Plasmas 17, (2010) Sarani, et al. Phys. Plasmas 17, (2010) 11

12 Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 12

13 A single electrode plasma jet device Pulse Generator Amplitude: up to 10 kv Pulse width: 200 ns to DC Repetition rate: up to 10 khz Geometry Nozzle: Φin=1.2 mm Syringe: Φin=6mm Quartz tube:φin=2mm Φout=4mm * X Lu, et al. Appl. Phys. Lett. 92, (2008) 13

14 IV Characteristic Two discharge current pulses per applied voltage pulse The discharge current is on the order of several hundreds ma The current carried by the plasma plume is slightly smaller than the discharge current 14

15 Effect of repetition frequency on current The higher the repetition frequency, the early the current appears. *Q. Xiong, et al. Phys. Plasmas, 16, (2009) 15

16 Rotational and vibrational temperature A finger can touch any part of the plasma plume without any feeling of electrical shock or warmth at all. The rotational and vibrational temperatures of the plasma plume are about 300K and 2950K, respectively. 16

17 Setup of Plasma relay Experimental setup *X Lu, et al. 2009, J. Appl. Phys. 105,

18 Photograph of plasma relay Photograph of the plasma 18

19 Dynamics of plasma relay The primary plasma disappears before the secondary plasma starts to propagate. The propagation velocity of the primary plasma is several times higher than that of the secondary plasma. 19

20 Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 20

21 A comparative analysis of a pulsed dc and ac excited plasma plume ( a ) Setup ; (b) AC driven (V pp =16 kv) and(c)pulsed DC driven (V=8 kv,pulse width 800 ns. Both frequency 4 khz,he flow rate 2 l/min. P pulse =1.8W, Pac=3.5 W. *Q. Xiong, et al. Phys. Plasmas. 17, (2010) 21

22 Emission spectra for Pulsed DC and AC Pulsed AC 22

23 Rot. and Vib. Temperature for Pulsed and AC Gas temperature Vibrational temperature 23

24 Decontamination effect for Pulsed DC and AC Pulsed AC Control Direct Indirect 24

25 Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 25

26 A RC plasma jet driven by pulsed DC voltage Schematic of the device *X Lu, et al. 2009, IEEE Tran. Plasma Sci.37,

27 Photograph of the device 27 Plasma in a tooth Plasma plume photo Plasma touched by a finger

28 IV of the plasma The displacement current waveform behaves as that of a typical RC charge and discharge circuit. The actual discharge current has a peak value of about 10 ma. The voltage on the needle has a peak of about 6 kv. The power deposited into the plasma is estimated to be less than 0.1W. 28

29 Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 29

30 A RC air plasma jet driven by pulsed DC *X. Lu, et al. Appl. Phys. Lett. 95, (2009) 30

31 Photograph of the plasma 31

32 IV of the plasma (a)i-v characteristic of the plasma. V 1, V 2, and V 3 are the voltages at three different locations. I is the discharge current. (b) Zoom in the first three discharge current spikes I and V 3. Several current spikes appear periodically for one voltage pulse. When the voltage applied on the needle reaches about 1.5 kv, the first discharge appears and the first current spike has a peak value of more than 1.5 A with a pulse width of about 10 ns. The 32 following current spikes have a peak value of about 0.5 A.

33 Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 33

34 Setup of the device 34

35 Photograph of the plasma The gas temperature of the plasma remains at room temperature. *S. Wu, et al. IEEE Trans. Plasma Sci. 38, 3404 (2010) 35

36 Discharge current for various applied voltage Gap distance of 4 mm The discharge actually appears periodically with a frequency of about 30 khz. The repetition frequency does not strongly depend on the applied voltage. 36

37 Discharge current for various gap distance V a = 18.5 kv With the increase of the gap distance, the pulse repetition frequency decreases significantly. The peak values of the discharge currents have no big difference for the three gap distances. *S. Wu, et al. IEEE Trans. Plasma Sci. (accepted) 37

38 IV of a single pulse for different V 10kV 18kV Although the peak value of the discharge current is quite high, the pulse width of the current is only about 100 ns. 38

39 Emission spectra of the plasma the spectrum is dominated by N 2 emission. Moreover, there is also O-atom emission. 39

40 Overview of the status of Cold Plasma Jets Recent Progress on plasma jet research in our lab A single electrode plasma jet device A comparative analysis of a pulsed dc and ac excited plasma plume A RC plasma jet driven by pulsed DC A RC air plasma jet driven by pulsed DC A self-pulsed air plasma needle Plasma jet array 40

41 Photograph of the plasma jet array *X. Pei, et al. IEEE Trans. Plasma Sci. (Accepted) 41

42 Dynamics of the plasma jet array The plasma plumes on both edges initiate early than that in the middle of the plasma array. The propagation speed of the plasma plume on both edges is higher than that in the middle of the plasma array. 42

43 Electric field distribution of the setup The electric field on both edges is higher than that in the middle of the plasma array. The differences of the dynamics of the plasma plumes is probably due to the electric field distribution of the plasma array. 43

44 Summary Because of their capability to generate plasmas that are not spatially bound or confined by electrodes, atmos. Pres. Non-equilibrium plasma jets are attracting lots of attentions in various applications. Not only room temperature noble gas plasma jets can be generated at surrounding air, but also room temperature air plasma can be generated. 44

45 45