Fundamental Physics Research on the ISS - CClPlomplex Plasmas and dbd beyond Gregor Morfill MaxMax--PlanckPlanck Institut für extraterrestrische Physik Fundamental Physics Workshop (RAL , 3 . 5 . 2006)

Plasmas - the ´´fourthfourth state of matter´matter´-- are also the most disordered state. However, so-called ´complex plasmas´ can exist as ordered liquids and crystals as well as gases. In addition they can be studied at the individual particle level. The talk focusses on some fundamental properties of these stltrongly coup ldtled systems an d on p lanne dftdld future developmen ts on thISSthe ISS.

Thanks go to: all my colleagues at MPE, who participate(d) in this research, my Russian partners V . Fortov , O . Petrov , V . Molotkov , A . Lipaev (all IHED) and the Cosmonauts, who performed some of the experiments. Special thanks also to: DLR/BMBF, Kayser-Threde GmbH, RSA, RKK-Energia, TSUP 1 What are ´Complex´Complex Plasmas´Plasmas´?? • CifilConsist of ions, electrons and chdharged microparticles (plus neutral gas), overall charge neutral

• The ((g)large) microp articles can be visualised individually

• The mitilbicroparticles can be dynamically dominant (mass density ⋍ 100 times larger than neutral gas density and ⋍10 million times larger than the ion density)

• Time scal es are ´stthdtretched´- the

(complex) plasma frequency is ~ 100Hz 2 Complex Plasmas –a new state of matter • The name was chosen in analogy to ´Complex Fluids´

• Complex Plasmas are the 4th state of this so-called ´soft matter´ ThomasThe states and Morfill, of Nature (1995) ´soft matter´ • Complex Plasmas can exist ComplexLiquid plasmas plasmas as essentially one-component or two-comppyonent systems Aerosol Crcloudsyypstalline plasmas

• Complex Plasmas can be Complex electrolytes strongly coupled and can Complex fluids exist in gaseous, liquid and crystalline states Granular liquids Granular solids 3 Discovery of liquid and crystalline plasmas gaseous

liquid

crystalline

Thomas et al., PRL (1994), Chu and I, PRL (1994), Thomas and Morfill, Nature (1996)4 Why can Complex Plasmas selfself--organise?organise? The interaction between the microparticles is electrostatic ( pottil)tential) … plus an l a ttttractive ti par tt… repulsive screened Coulomb Charged microparticle Debye sphere - - + +

2λ~100a Complex plasmas are ´optically thin´ up to ~ 10 cm in depth

PKE-Nefedov 5 Why can Complex Plasmas selfself--organise?organise? The interaction between the microparticles is electrostatic ( pottil)tential) … plus an l a ttttractive ti par tt… repulsive screened Coulomb Charged microparticle CCD video camera grounded electrode macro lens Debye sphere particles - laser sheet ‘shunt’ - 13.56 MHz resistor generator+ RFRF--electrodeelectrode+ The order parameters are: matching ring cylindrical laser network (copper) lens Γ = ES energy / Kinetic energy 2λ≥100a

Κ = ppp/article separation / shielding distance

6 Experiments in Space

„ The microparticles (a few µm diameter) have masses ≥ 1012 atitomic masses.

„ Hence gravity is a major factor and high precision experiments require microgravity.

„ Since 2001 MPE and IHED (Moscow) have been conducting experiments on the ISS with complex plasma laboratories: PKEPKE--NefedovNefedov (2001(2001--2005)2005) PKPK--3Plus3Plus (since 2006) PK-4(i4 (in ph ase A/B , co-co-financed ESA/DLR)

„ In addition there has been a great deal of laboratory research on Earth. 7 Location of PKE-Nefedov and PK -3Plus on the ISS

ISS Service Module

Both labo r atori es are located within the transfer compartment

8 PKE-Nefedov

~ 50 kg

Sergei K. Krikalev 9 PKE-NefedovPKPK--3Plus3Plus plasma plasma laboratory laboratory (ISS(ISS 2001 s ince-2005) 2006)

10 ´Plasma-Lab´ a plan for a fundamental physics laboratory in space (on the ISS) and some major research aims…

Proppyosal outline formulated by: Vladimir Fortov and Gregor Morfill (with the help of many partners and colleagues in Russia and Europe - and based in part on the ESA IAO 2004)

11 Plasma-Lab: a new ESA ,DLR ,Russia initiative BE condensation

Based on the IMPACT facility

The plans are to develop and build a modular science rack system for installation on the new Russian MLM module on the International Space Station. By utilising the same infrastructure for several experiment (laboratory) inserts, considerable cost savings are possible.

12 Plasma-Lab: a new ESA ,DLR ,Russia initiative BE condensation

First science insert: RF plasma laboratory ((tiftthtiti)equation of state, phase transitions) Second science insert: BEC gas (and quantum plasma) laboratory Third science insert: DC/RF plasma laboratory (kinetic study of liquids)

13 Plasma-Lab: a new ESA ,DLR ,Russia initiative BE condensation 1000 er year pp

Granular materials Bose-Einstain condensates

ications Colloidal suspensions ll Complex (dusty) plasmas

Pub 100 1996 1998 2000 2002 2004 Year

14 Plasma-Lab: a new ESA ,DLR ,Russia initiative

First science insert: RF plasma laboratory (adaptive electrodes)

Main scientific aims:

• explore the equation of state of this 4th state of soft matter (crystalline, liquid, gaseous) • investigate the physics at the ´critical point´ at the most basic (particle dynamics) level • investigate the onset of catastrophic transitions at the most elementaryy( (kinetic) level • research the origin of (non(non--equilibrium,equilibrium, nonlinear) phase transitions

etc.

15 thiffhe equation of state of ´complllex plasmas´

1Are1. Are ´complex plasmas plasmas´ a new new state state of matter? of matter? 2. If so, what is the thermodynamics? 3 Is. there Is there any new any physics new physics and what, isand it? what is it?

16 Equation of state of Complex Plasmas: NonNon--HamiltonianHamiltonian physics

Two effects are responsible for the non-Hamiltonian properties of Complex Plasmas: Sir William Rowan Hamilton: „On a general method in dynamics“ (1835) 1) Charge fluctuations, making the interaction potential time/space dependent 2 H(q, p) = ∑ pi /2mi +U+ U 2) Charge ´cannibalism´, making the interaction potential qν = ∂H/∂pν pν= - ∂H/∂qν density dependent Hamiltonian formalism is used to Studying non-Hamiltonian describe all physical systems (set of physics with complex plasmas movitil)thtding particles) that undergo (ililblitl(an easily available experimental changes by processes that maximise system) at the most elementary or minimise ´action´. kinetic level opens a whole new field of research in fundamental physics.

Ivlev et al. (2004, 2005), Havnes et al. (1984) 17 Equation of state of Complex Plasmas: NonNon--HamiltonianHamiltonian physics

Two effects are responsible for the non-Hamiltonian properties of Complex Plasmas: Sir William Rowan Hamilton: „On a general method in dynamics“ (1835) 1) Charge fluctuations, making the interaction potential time/space dependent 2 H(q, p) = ∑ pi /2mi +U+ U 2) Charge ´cannibalism´, making the interaction qν = ∂H/∂pν pν= - ∂H/∂qν potential density dependent Hamiltonian formalism is used to Studying non-Hamiltonian describe all physical systems (set of physics with complex plasmas movitil)thtding particles) that undergo (ililblitl(an easily available experimental changes by processes that maximise system) at the most elementary or minimise ´action´. kinetic level opens a whole new field of research in fundamental physics.

Ivlev et al. (2004, 2005), Havnes et al. (1984) 18 Example: the ´classical tunnel effect´

Morfill et al., NJP (2006) 19 The ´classical tunnel effect´

Charge cannib ali sm: the available charge is redistributed from 3 to 4 particles, reducing the interstitial potential well and allowing particle penetration.

20 CounterCounter--example:example: why doesn´doesn´tt it work here?

Ivlev et al., NJP (2005) 21 Example: Study of kinetic properties of liquids at the ´critical´critical point´point´

Near the critical point, systems attain a universal power law behaviour of thermodynamic and transport properties (as function of an ordtder parameter – e.g. dit)density)*.

• This implies that the systems lose allmemoryofscalesall memory of scales – why?

• We wish to explore the kinetic origin of of this this phenomenon phenomenon.

• Experiments planned on the International Space Space Station. Station.

*(K. Wilson, 1982) 22

23 ment (2005) = 3 Pa we have maximal p the range of attractive interaction increases m. μ too. For example at ~ 5 a increases c decreasing pressure T = 2 eV at c and T With 9 Khrapak et al. Khrapak (PRL, 2005) Universality and Scaling near the critical point:

1) Do Non-Hamiltonian systems have a Critical Point? 2) What is the Universality Class of liquid complex plasmas? PK-3Plus 3) What are the Order Parameters? 4) What is the effect of finite particle size and inertia? 5) What is the origin of the scale -free PK-4 behaviour, when viewed at the fundamental (kinetic) level? 6) What is the physics at the critical point in anisotropic systems? etc.

24 IMPACT Plasma-Lab: a new ESA ,DLR ,Russia initiative BE condensation

Second science insert: BEC gas (and quantum plasma) laboratory

Main scientific aims:

• produce massive, longlong--livedlived BECs and investigate their properties • investigate the physics of interacting BEC gases at the most basic (particle dynamics) level • investigate the formation of BEC crystals and their ppproperties • research the possibility of BoseBose--FermiFermi phase transitions (quantum plasmas)

etc.

25 BE Gases and Quantum Plasmas: more topics

1) Interaction of ensembles of neutral BEC´s of matter waves 2) Dipolar quantum gases

3) Coherent multiple multiple scattering scattering

4) New phase phase transitions transitions

5) Bose crystals

6) Massive BEC´s

)7 Physics of ´charged´ interacting BEC´s – do such ´quantum plasmas´ exist?

etc.

Cornell, Ketterle and Wieman, 2001 26 Interacting quantum gases and ´quantum plllasmas´… a possibility? e.g. a 1eV photoelectron BE condensation imparts a (kinetic) energy of ~ 0.1nK to a BECCo of 10 9 Rbbato atoms – i.e. we suddenly have a giant Fermion.

What will such a system do? to ´´dissolvedissolve´´––not enougggyh energy… form Cooper pairs –reaction scale… evaporate partially – time scale...

Proposal to ESA: Ertmer, Morfill, Fortov, Rempe, Thoma, Thomas, Rasel, Dittus…(2004) 27 Plasma-Lab: a new ESA ,DLR ,Russia initiative

Third science insert: DC/RF plasma laboratory (kinetic study of liquids)

Main scientific aims:

• explore the onset of cooperative phenomena in fluid systems at the kinetic level • investigate the origin of turbulence at the most elementary (particle interaction) level • investigate shear flows at the ´discrete´discrete´´limit of particle flows • research the physics of nonnon--HamiltonianHamiltonian fluids at the kinetic level

etc.

28 cooperativeexploring behaviour? the onset of

cooperativethemselves at the kinetic phenomena level?

1. Wh dl t ti l ti d i t en do interacting particle systems develop e.g. surface tension, viscosity, develop? 2H2. How d ti do coopera ift h tive phenomena manifest

3H3. How i d t tido macroscopic system properties,

4Whtith4. What is the relation t ltio nanoflu tidi flidi?cs? 5. What is the new physics?

29 Example 1. The hydrodynamic limit

„ WhenHowever the system size, L, is too small compared to characteristic length scales of the fluid, the hydrodynamic description has to be replaced by e .g . molecular dynamics. For li λ/ This is expected to occur when the Knudsen Number Kn= L ≥ 0.01.

,,gg some results from nanofluidics suggest that hydrodynamics may apply even when Kn≈ 0.25 *.

qqppuid complex plasmas, λ ≈ λD , which is about 50μm. Such systems are easy to produce and study.

„ The onset of cooperative behaviour can only be investigated at the kinetic level –complex plasmas are ideal candidates.

* Mugele and Persson, J. Phys. Cond. Matt. 16, R295 (2004), Becker and Mugele, PRL 91, 166104 (2003) 30 Limits of co -operative phenomena: converging and diverging laminar flows first observations at the kinetic limit

v

Fink et al. (2005) 31 2. Waves & turbulence in particle jet flow at the cooperative limit by a glass tube constriction A introduced´Laval nozzl ine ´a is dc. produced discharge

complex plasma flow.

collective

single

Fink et al. 2005 (PK-4, parabolic flight) 32 pathways to equilibrium in strongly coupled systems

1. What are the principal (kinetic) processes for the gy conversion? free ener 2. Are there different how are they selected? 3. How do strongly coupled systems differ from paths to equilibrium and weakly coupled systems? 4 Are. Are instabilities instabilities started started by single by particles? single particles? 5. What is the role of non-Hamiltonian ? effects

33 1. Two stream instability - soliton production 2. Two-stream instability - a non-equilibrium phtitihase transition

Kretschmer et al. (2004) – parabolic flight measurements (PK-4) 35 etc.

36 Plasma-Lab: a new ESA ,DLR ,Russia initiative BE condensation currentttt status and next steps

37 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative current status Preparations for the proposed science inserts: BE condensation

Two RF Plasma laboratories have already been installed on the ISS. Adaptive electrode development is now in it s thi rd year (f und ed b y DLR and MPG) . A DC Plasma laboratory for the ISS has been studied in a DLR project, and phase B is currently funded by ESA. A BEC project under microgravity (drop tower) is under way, a Texus (rocket) experiment has been approved by DLR . The modular IMPACT rack strategy has been studied by industry at the system level (DLR and ESA funded).

38 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative current status BE condensation Esa support(it (in pri nci pl e) exi st s, h owever, ELIPS ELIPS2 2 funding is too low. The decision to develop MLM science racks has been advocated within ESA. DLR is in favour of supporting this initiative . A budget of 10 Mio. Euros (nationally) has been earmarked for 2007 – 2010. The Russian Academy of Sciences has expressed its resolve that participation in PlasmaPlasma--LabLab has their highest priority in future space missions.

A letter to M. Sacotte (ESA) to start negotiations has been sent. M. Sacotte supports the cooperation.

39 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative the next steps BE condensation 1. Detail the division of responsibilities and the resources:

MLM rack including all infrastructure (ESA) Science inserts (DLR and Science Coordinators) ISS resources in MLM,,p,g, transport, logistics, cosmonauts, training (Russia)

40 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative the next steps BE condensation

2. Select prospective project teams and the team coordinators

3. Constitution of an international science advisory board.

41 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative the next steps BE condensation 4. C ont rac t nego tia tions (MOU) b et ween ESA and RKK-RKK-Energia/RSAEnergia/RSA on the MLM activities.

5. Contract discussions (MOU) between DLR, RKK Energia and the Science PIPI´´ss ((,p)Russia, Europe) on the science inserts.

42 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative the next steps BE condensation 6. System study by Industry/Scientists for the Plasma-Plasma-LabLab requirements.

7. PrePre--developmentdevelopment (Phase A/B) could start immediately - once agreement has been obtained, both at ESA and DLR level as well as in Russia .

43 PlasmaPlasma--Lab:Lab: a new ESA,DLR,Russia initiative the next steps BE condensation

Other scientific partners, international scientific consortia, with hardware and/or software responsibilities, laboratory support studies, etc.: are more than welcome!

44 45 Velocity profile through nozzle

collective

single

46 Example: Waves & turbulence in particle jet flow at the cooperative limit by a glass tube constriction A introduced´Laval nozzl ine ´a is dc. produced discharge

complex plasma flow.

collective

single

Fink et al. 2005 (PK-4, parabolic flight) 47 Limits of co -operative phenomena

2. Kinetics of ´jet´jet´´formation

PK-4

Fink, Thoma, Morfill, Fortov, Petrov, Usachev …(2005) 48 particle motion in front of a nozzle

A ´Laval nozzle´ is ppygroduced by a glass tube constriction introduced in a dc. discharge complex plasma flow.

PK-4

Fink et al. 2005 (PK-4, parabolic flight) 49 (atoms) interaction lengths, already exhibit hydrodynamic (cooperative) properties. Kinetics of jet formation: preliminary conclusions

„ ´Nano-jets´, consisting of of dimensions dimensions ~ 10 particle particle

still needs to be investigated in detail.

„ The ´jet effect´ - acceleration to supersonic speeds - (or in the the case case of complex of complex plasmas plasmas to larger to than larger the dustthan the dust- acoustic speed) is observed. investigated. „ Thhfllllbhe transition from single particle to collective behaviour

„ New effects have been seen (reverse shocks, rarefaction waves, reverse dust-acoustic waves, transverse flow oscillations) The. The possible possible generic generic role needs role toneeds be to be

50 Paths to equilibrium

„ ItIn strongl ly coup ldtled twowo--ssttthtream systems there appear to be at least two paths to reaching the final equilibrium state:

1F1. Free energy diidissipati on b y waves 2. Non-Non-equilibriumequilibrium phase transition

„ The rules gggoverning the choice of these paths (and maybe others) have not been determined yet.

51 52 53 Accommodation of PKE-PKE-NefedovNefedov in the International Space Station

54