xinpei lu - iaea scientific and technical publications · advance on non-equilibrium plasma jets. 2...

XinPei Lu

[email protected]

College of EEE, HUST

Advance on non-equilibrium plasma jets

2

Outline��OverviewOverview ofof thethe statusstatus ofof ColdCold PlasmaPlasma JetsJets

��RecentRecent ProgressProgress onon plasmaplasma jetjet researchresearch inin ourour lablab

� A single electrode plasma jet device

� A comparative analysis of a pulsed dc and ac

excited plasma plume

� ARC plasma jet driven by pulsed DC

� ARC air plasma jet driven by pulsed DC

� A self-pulsed air plasma needle

� Plasma jet array

3

Overview of the status of Cold Plasma Jets

�RF Hicks group, 1998 Plasma Sources Sci. Technol. 7 286-8

�E Stoffels, et al 2003 J. Phys. D: Appl. Phys. 36 2808-13

♥Gas temperature can be as

low as tens of Celsius degree.

♥The risk of arcing exists.

♥Gas temperature is

sensitive to the

distance from the

needle tip. It can be

at room temperature.

4

�Stonies R, et al. 2004 Plasma Sources Sci. Technol. 13 604-11

�Teschke M, et al 2005 IEEE Trans Plasma Sci. 33, 310-1

♥Gas temperature is

quite high. It can be

touched by a finger for

few seconds.

♥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

5

�Laroussi M and Lu X 2005 Appl. Phys. Lett. 87 112902

�Hong Y C, et al 2006 Appl. Phys. Lett. 89 221504

♥When N2 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 500µµµµm.

♥The plasma is driven

by pulsed DC voltage.

It can have a length of

about 5cm.

6

�C. Jiang, et al 2009 Plasma Processes and Polymers. 6

�H. Kim, et al. 2009 Appl. Phys. Lett. 95, 211501

♥Applied voltage

134.7 kHz; Vpp is

less than 600 V;

working gas Ar.

♥Driven by

pulsed DC high

voltage, pulse

frequency: 1 kHz;

amplitude 6 kV.

7

�Q. Nie, et al 2008 Appl. Phys. Lett. 93, 011503

�X. Zhang, et al. 2008 Appl. Phys. Lett. 93, 0215022.7kV 4kV 5kV 5.6kV

♥Applied voltage

48 kHz; working

gas Ar.

♥Ar is fed through the side arm of

the tube, and O2 is injected into the

end of quartz tube through the

inner electrode to react with Ar

plasma.

♥Electron attachment inside the

tube is weakened.

8

�H. Lee, et al 2010 Plasma Processes & Polylers 7, 274

�T. Ni, et al. 2008 Appl. Phys. Lett. 92, 241503

♥Applied voltage 20 kHz; working

gas Helium. The plasma jet was

used in combination with H2O2 to

remove stains from teeth stained

by either coffee or red wine.

♥Applied voltage 1

kHz; working gas N2

9

� J. Kolb, et al. 2008 Appl. Phys. Lett. 92, 241501

�Y. Hong, et al. 2009 Phys. Plasmas, 16, 123502

♥Applied voltage

60 Hz; working

gas Air.

♥DC voltage;

working gas Air.

1010101010

� Leveille V , et al. Plasma Sources Sci. Technol. 14 467 (2005)

� Lai W, et al. Phys. of Plasmas 12 023501 (2005)

� Forster S, et al. Surface & Coatings Technol. 200 827 (2005)

� Xu L, et al. Thin Solid Films 506-507 400 (2006)

� Chen G, et al. Plasma Sources Sci. Technol. 15 603 (2006)

� Walsh J L, et al. Appl. Phys. Lett. 88 171501 (2006)

� Kim D, et al. Appl. Phys. Lett., 91 151502 (2007)

� Lu X, et al. Appl. Phys. Lett. 92 151504 (2008)

� Lu X. et al. Appl. Phys. Lett. 92 081502 (2008)

� Sands B, et al. Appl. Phys. Lett., 92 151503 (2008)

� Y. Hong, H. Uhm, W. Yi, Appl. Phys. Lett. 93, 051504 (2008)

� J. Walsh and M. Kong, Appl. Phys. Lett. 93, 111501 (2008)

� Shashurin, et al. Appl. Phys. Lett. 93, 181501 (2008)

11

� J. Kim, et al. Appl. Phys. Lett. 93, 191505 (2008)

� S. Kim, et al. Appl. Phys. Lett. 94, 141502 (2009)

� W. Zhu, Q. Li, X. Zhu, and Y. Pu, J. Phys. D 42, 202002 (2009)

� N. Jiang, A. Ji, and Z. Cao, J. Appl. Phys. 106, 013308 (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, 231504 (2009)

� S. Deng, et al. Current Appl. Phys. 10, 1164 (2010)

� Q. Li, X. Zhu, J. Li, Y. Pu, J. Appl. Phys. 107, 043304 (2010)

� M. Qian, et al. J. Appl. Phys. 107, 063303 (2010)

� S. Kim, et al. Phys. Plasmas 17, 053504 (2010)

� Sarani, et al. Phys. Plasmas 17, 063504 (2010)

12

��OverviewOverview ofof thethe statusstatus ofof ColdCold PlasmaPlasma JetsJets









A single electrode plasma jet device

13

Pulse Generator

Amplitude: up to 10 kV

Pulse width: 200 ns to DC

Repetition rate: up to 10 kHz

Geometry

Nozzle: ΦΦΦΦin=1.2 mm

Syringe: ΦΦΦΦin=6mm

Quartz tube:ΦΦΦΦin=2mm

ΦΦΦΦout=4mm

**X Lu, et al. Appl. Phys. X Lu, et al. Appl. Phys. LettLett. 92, 151504 (2008). 92, 151504 (2008)

IV Characteristic

14

♥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

15

Effect of repetition frequency on current

*Q. *Q. XiongXiong, et al. Phys. Plasmas, 16, 043505 (2009), et al. Phys. Plasmas, 16, 043505 (2009)

♥The higher the repetition frequency, the early the current

appears.

Rotational and vibrational temperature

16

♥The rotational and vibrational

temperatures of the plasma plume are

about 300K and 2950K, respectively.

♥A finger can touch

any part of the plasma

plume without any

feeling of electrical

shock or warmth at all.

Setup of Plasma relay

17

Experimental setup

*X Lu, et al. 2009, J. Appl. Phys. 105, 043304*X Lu, et al. 2009, J. Appl. Phys. 105, 043304

Photograph of plasma relay

18

Photograph of the plasma

Dynamics of plasma relay

19

♥ 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.

20










21

（（（（ a ）））） Setup ；；；； (b) AC driven

(Vpp=16 kV) and（（（（c））））Pulsed DC

driven (V=8 kV，，，，pulse width 800

ns. Both frequency 4 kHz，，，，He

flow rate 2 l/min.

A comparative analysis of a pulsed dc and ac


*Q. *Q. XiongXiong, et al. Phys. Plasmas. 17, 043506 (2010), et al. Phys. Plasmas. 17, 043506 (2010)

♥Ppulse=1.8W, Pac=3.5 W.

22

Emission spectra for Pulsed DC and AC

←←←←Pulsed

←←←←AC

23

Rot. and Vib. Temperature for Pulsed and AC

Gas temperature Vibrational temperature

24

Decontamination effect for Pulsed DC and AC

←←←←Pulsed

←←←←AC

Direct IndirectControl

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, 668*X Lu, et al. 2009, IEEE Tran. Plasma Sci.37, 668

27

Photograph of the device

Plasma plume photo

Plasma in a tooth

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.

29










A RC air plasma jet driven by pulsed DC

30

*X. Lu, et al. Appl. Phys. Lett. 95, 181501 (2009) *X. Lu, et al. Appl. Phys. Lett. 95, 181501 (2009)


31

IV of the plasma

32

(a)I-V characteristic of the plasma. V1, V2, and V3 are the voltages at three

different locations. I is the discharge current. (b) Zoom in the first three

discharge current spikes I and V3.

♥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

following current spikes have a peak value of about 0.5 A.

33










34

Setup of the device


35

*S. Wu, et al. IEEE Trans. Plasma Sci. 38, 3404 (2010) *S. Wu, et al. IEEE Trans. Plasma Sci. 38, 3404 (2010)

♥ The gas temperature of the plasma remains at room

temperature.

36

Discharge current for various applied voltage

♥ The discharge actually appears periodically with a frequency

of about 30 kHz.

♥ The repetition frequency does not strongly depend on the

applied voltage.

Gap distance of 4 mm

37

Va = 18.5 kV

Discharge current for various gap distance

♥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) *S. Wu, et al. IEEE Trans. Plasma Sci. (accepted)

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.

39

♥ the spectrum is dominated by N2 emission. Moreover,

there is also O-atom emission.

Emission spectra of the plasma

40










41

Photograph of the plasma jet array

*X. Pei, et al. IEEE Trans. Plasma Sci. (Accepted) *X. Pei, et al. IEEE Trans. Plasma Sci. (Accepted)

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



43

Electric field distribution of the setup

♥ The electric field on

both edges is higher



♥ The differences of the

dynamics of the plasma

plumes is probably due

to the electric field

distribution of the

plasma array.

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.

xinpei lu - iaea scientific and technical publications · advance on non-equilibrium plasma jets. 2...

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