Summer College on Plasma Physics August Discoveries in Dusty Plasmas. Padma K. Shukla Ruhr-Universität Bochum Germany

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1 Summer College on Plasma Physics August 2009 Discoveries in Dusty Plasmas Padma K. Shukla Ruhr-Universität Bochum Germany

2 Discoveries in Dusty Plasmas: 20 Years of the Dust Acoustic Wave AS-ICTP, Trieste, 25 August 2009 PADMA KANT SHUKLA SUPA, Dept. Physics, U. Strathclyde, Glasgow, Scotland Faculty of Physics & Astronomy, Ruhr-U. Bochum, Germany ps Collaborator: Bengt Eliasson (Ruhr-U. Bochum, Germany)

3 AS-ICTP, TRIESTE, 25AUGUST A. INTRODUCTION OUTLINE B. PROPERTIES OF DUSTY PLASMAS C. DUST CHARGING D. NEW WAVES/NEW INSTABILITIES E. NEW FORCES: WAKE FIELDS F. NONLINEAR STRUCTURES: MACH CONES, DIA SHOCKS, VOIDS, VORTICES G. CONCLUSION

4 AS-ICTP, TRIESTE, 25AUGUST INTRODUCTION OCCURRENCE OF DUSTY PLASMAS: IN SPACE NEBULAS, MOLECULAR CLOUDS, SUPERNOVAE, SATURN RINGS, MARTIAN ENVIRONMENTS AND COMETARY TAILS IN UPPER ATMOSPHERE AND NOCTILUCENT CLOUDS IN POLAR MESOSPHERE IN COMMERCIAL PLASMA ETCHING REACTORS: MICROELECTRONICS & NANOTECHNOLOGY NEW MATERIALS: DUST-PLASMA CRYSTALS IN FUSION REACTORS: IN MANY TOKAMAKS AND IN ITER IN MICROBIOLOGY AND DESINFECTION IN MEDICINE/DENTAL TREATMENT

5 AS-ICTP, TRIESTE, 25AUGUST DUSTY PLASMA DEFINITION DUSTY PLASMAS ARE MULTI-COMPONENT PLASMAS THEY CONTAIN ELECTRONS, IONS, NEUTRAL ATOMS/MOLECULES, AND MICRO-PARTICLES/CHARGED DUST GRAINS THEY ARE SIGNIFICANTLY DIFFERENT FROM THE USUAL ELECTRON-ION PLASMAS DUST CHARGING AS A DYNAMICAL VARIABLE NEW SPACE AND TIME SCALES ASSOCIATED WITH DUST PARTICLE MOTION

6 AS-ICTP, TRIESTE, 25AUGUST

7 AS-ICTP, TRIESTE, 25AUGUST EAGLE NEBULA

8 AS-ICTP, TRIESTE, 25AUGUST SATURN RINGS

9 AS-ICTP, TRIESTE, 25AUGUST HALE-BOPP & HYAKUTAKE

10 AS-ICTP, TRIESTE, 25AUGUST MESOSPHERIC NOCTILUCENT CLOUDS T. W. Backhouse, Meterol. Mag. 20, 133 (1885).

11 AS-ICTP, TRIESTE, 25AUGUST MICROELECTRONICS

12 AS-ICTP, TRIESTE, 25AUGUST FORMATION OF DUST STRUCTURES

13 AS-ICTP, TRIESTE, 25AUGUST JET TOKAMAK

14 AS-ICTP, TRIESTE, 25AUGUST DUST IN FUSION DEVICES

15 AS-ICTP, TRIESTE, 25AUGUST CHARGING MECHANISMS

16 AS-ICTP, TRIESTE, 25AUGUST CHARGING MECHANISMS (continued)

17 AS-ICTP, TRIESTE, 25AUGUST CHARGING MECHANISMS (continued)

18 AS-ICTP, TRIESTE, 25AUGUST First prediction by H. Ikezi, Phys. Fluids (1986); Observations: Wu & Lin I, PRL (1994), Thomas et al, PRL (1994).

19 AS-ICTP, TRIESTE, 25AUGUST

20 AS-ICTP, TRIESTE, 25AUGUST PROPERTIES OF DUSTY PLASMAS Electron ion plasma Dusty plasma n e0 = i Z in i0 Q d n d0 + en e0 = e i Z in i0 Q i = Z i e Q d = Z d e Q i Z i =const. dq d /dt = I e + I i + I s +... m i m d m i λ De λ D λ Di Uniform particle sizes Size distributions Particle E B 0 motion Dust E B 0 motion at low B 0 requires high (Tesla) B 0 IAW, EIC, f 1 khz DAW, DLW, SW, f 10 Hz,

21 AS-ICTP, TRIESTE, 25AUGUST PROPERTIES OF DUSTY PLASMAS Electron ion plasma IA Solitons Compression/Rarefaction Debye Hückel Interactions El. & Ion Crystalization Wigner Crystals Phase Transition Dusty plasma DAW Shock Waves/Holes Mach Cones Attractive Forces, Ion Drag Dust Crystals Cryogenic Plasmas Phase Transition Solid State Crystals Dust Crystals Z i > 1 Z d E interaction afewev E interaction 900 ev Lattice Spacing L 0.1 nm L 1 mm

22 AS-ICTP, TRIESTE, 25AUGUST EXISTENCE DIAGRAM

23 AS-ICTP, TRIESTE, 25AUGUST Thomas et al., PRL (1994).

24 AS-ICTP, TRIESTE, 25AUGUST DIFFERENT PHASES Morfill & Thomas, Nature, 1996.

25 AS-ICTP, TRIESTE, 25AUGUST COLLECTIVE PROCESSES: PHYSICS OF WAVES Restoring Forces Inertia Phase Speed SW Neutral Gas Mass of (T n /m n ) 1/2 Pressure Neutral Atoms IAW Electron Pressure Ion Mass C s =(T e /m i ) 1/2 DIAW Electron Pressure Ion Mass (n i0 /n e0 ) 1/2 C s DAW Ion Pressure Dust Mass Z d (n d0 T i /n i0 m d ) 1/2 Electron Pressure Dust Mass Z d (n d0 T e /n e0 m d ) 1/2 AW Magnetic Tension Ion Mass (B0/8πn 2 i0 m i ) 1/2 DALW Magnetic Tension Dust Mass (B0/8πn 2 i0 m d ) 1/2

26 AS-ICTP, TRIESTE, 25AUGUST DUST ACOUSTIC WAVES Observation: A. Barkan, R. L. Merlino, and N. D Angelo, 1995, Phys. Plasmas ; Prediction: P. K. Shukla, 1st Dusty Plasma Workshop Proc., July 1989.

27 AS-ICTP, TRIESTE, 25AUGUST RSY Linear & Nonlinear DAW Theory and Observation N. N. Rao, P. K. Shukla, and M. Y. Yu, 1990, Planet. Space. Sci 38, 543. A. Barkan, R. L. Merlino, and N. D Angelo, 1995, Phys. Plasmas (n d /n i , Z d , m d g, T i 0.2 ev, T e 3 ev) Theory Observation v ph = Z d ( T i n d m d n i ) =9cm/s v ph =10cm/s (λ =0.6 cm, ν =15Hz)

28 AS-ICTP, TRIESTE, 25AUGUST DUST ACOUSTIC-LIKE WAVES Ticos, Smith & Shukla, Plasma Phys. Contr. Fusion, 2004.

29 AS-ICTP, TRIESTE, 25AUGUST TWO-STREAM ION-DUST INSTABILITY Dispersion relation (Shukla & Mamun, Introduction to Dusty Plasma Physics, IOP, 2002) 1+ 1 k 2 λ 2 D Definitions: ω 2 pi (ω ku)(ω ku + iν i ) ω 2 pd ω(ω + iν d ) =0 ( ) Pn ν i = σ i u B T n ν d = 4 3 πr2 d ( Pn T n ) V Tn m n m d

30 AS-ICTP, TRIESTE, 25AUGUST SOLUTION OF THE DISPERSION RELATION

31 AS-ICTP, TRIESTE, 25AUGUST Mach Cone: Movie

32 AS-ICTP, TRIESTE, 25AUGUST PHYSICS OF MACH CONES

33 AS-ICTP, TRIESTE, 25AUGUST MACH CONES IN DUST CRYSTALS

34 AS-ICTP, TRIESTE, 25AUGUST DOUBLE MACH CONES

35 AS-ICTP, TRIESTE, 25AUGUST WAKE FIELD

36 AS-ICTP, TRIESTE, 25AUGUST ION WAKE

37 AS-ICTP, TRIESTE, 25AUGUST ION WAKE, KINETIC DESCRIPTION D. D. Tskhakaya, P. K. Shukla, and B. Eliasson, Phys. Lett. A 331,

38 AS-ICTP, TRIESTE, 25AUGUST THEORY OF DIA SHOCK WAVES DISSIPATION + DISPERSION ( ) ω kc s 1 k2 2k0 2 WAVES IN A DISSIPATIVE MEDIUM iνk 2 λ 2 u t + C u s x + C s 3 u 2k 0 x 3 = u νλ2 2 x 2

39 AS-ICTP, TRIESTE, 25AUGUST K-dV-BURGERS EQUATION THEORY OF DIA SHOCK WAVES WITHOUT DISPERSION u t + αu u x + C s 3 u 2k0 2 x 3 = u νλ2 2 x 2 WITH u = V (1 tanhθ) θ = V (x Vt) δ s, δ s =2νλ 2, α =1

40 AS-ICTP, TRIESTE, 25AUGUST DIA SHOCK WAVE: SIMULATIONS & OBSERVATIONS Nakamura, Bailung & Shukla, Phys. Rev. Lett. 1999

41 AS-ICTP, TRIESTE, 25AUGUST DIA SHOCK WAVE: VLASOV SIMULATION T i /T e =0.1, n e0 /n i0 =0.25 Eliasson & Shukla, Phys. Plasmas, 2004.

42 AS-ICTP, TRIESTE, 25AUGUST DIA SHOCK WAVE: VLASOV SIMULATION T i /T e =1, n e0 /n i0 =0.05 Eliasson & Shukla, Phys. Plasmas, 2004.

43 AS-ICTP, TRIESTE, 25AUGUST MOVIE OF VORTICES AROUND DUST VOID

44 AS-ICTP, TRIESTE, 25AUGUST MOVIE OF DUST VOID CLOSURE

45 AS-ICTP, TRIESTE, 25AUGUST DUST VOID IN MAGNETIZED PLASMAS Jovanović & Shukla, Phys. Lett A, 2004.

46 AS-ICTP, TRIESTE, 25AUGUST SUMMARY & CONCLUSIONS A. WE HAVE DISCUSSED PROPERTIES OF DUSTY PLASMAS B. DUST CHARGING C. OCCURRENCE OF DUSTY PLASMAS IN SATURN RINGS, COMET TAILS, SPACE NEBULAS AND IN NOCTILUCENT CLOUDS IN POLAR MESOSPHERE D. DUST IN COMMERCIAL PLASMA ETCHING REACTORS AND IN TOKAMAKS E. NEW FORCES: WAKE FIELDS F. NONLINEAR STRUCTURES: MACH CONES, DIA SHOCKS, VOIDS, VORTICES