Dust and Grains in Low Gravity and Space Environment, ESTEC April 2-4, 2012 Research opportunities of the dust cloud manipulation system for Interaction in Cosmic and Atmospheric Particle Systems project (ICAPS) A. Vedernikov, N. Freuville, A.Cecere, D.Balapanov Microgravity Research Center, Université Libre de Bruxelles, Brussels, Belgium J.Blum, I. Von Borstel, R.Schrapler Institut für Geophysik und Meteorologie, Technische Universitat Braunschweig, Braunschweig, Germany 1
ESA project for ISS: Interaction in Cosmic and Atmospheric Particle Systems (ICAPS) 2
Experimental simulation of early stage processes of proto-planetary matter formation Agglomeration Accretion ~1 µм ~1 кm ~10000 кm Prevailing particle-gas interaction Gravity dominates Solid dust particles Planetesimals ~ 10 4-10 6 years? ~ 10 7-10 8 years? Dust agglomeration. J.Blum, Advances in Physics, Vol. 55, Nos. 7 8, 2006, 881 947 The Growth Mechanisms of Macroscopic Bodies in Protoplanetary Disks J. Blum and G.Wurm, Annu. Rev. Astron. Astrophys. 2008. 46:21 56 Planets Courtesy of J.Blum 3
Laboratory astrophysical experiments Goals - find experimental parameters: sticking probabilities; aggregate structure; aggregation kinetics; aggregate light scattering properties; aggregate transport properties; dynamics of heavy loaded clouds; etc. For more information: Dust Particles in Space. J. Blum et al., EuroPhysics News, 2008, 39/3, p. 27. The picture is courtesy of J.Blum 4
Typical experiment conditions Particle size - micrometers Particle concentration ~10 6 /сm3 Size distribution - mostly monomers Gas pressure - 0.001 atm Temperature ambient (around 20C) Chamber size ~10 cm The cloud is electrically neutral individual particles are charged (+ & -) mean absolute charge is about 2 e Rapid sedimentation at 1g!!! 5
Problems even in microgravity: Residual forces (mostly thermophoretic) remove the cloud. Already 0.01 K/cm is not tolerable cloud disappears in 2-4 minutes! 0g 0 6
Problems even in microgravity (0g): Agglomeration results in particle number density decrease (depletion) and increase of mean size Growth rate of quasi-monodisperse cloud 2 n ( i, t) n ( i, t) t i n number density of particles containing i monomers 0g 0 7
Requirements for Cloud Manipulation System: 1. Counterbalance residual forces 2. Make particles moving towards the center (cloud squeezing ) ideally to get at the end one agglomerate (mm size) 0g 0 8
Requirements for Cloud Manipulation System 1. Counterbalance residual forces 2. Make particles moving towards the center (cloud squeezing ) 3. A chosen agglomerate should be delivered to the field of view of microscope and kept there for measurements 0g 0 9
Requirements for Cloud Manipulation System 1. Counterbalance residual forces 2. Adapt cloud shape 3. Counterbalance Brownian spread 4. Make particles moving to the center (cloud squeezing ) 5. A chosen agglomerate should be delivered to the field of view of the microscope and kept there for measurements Cloud Manipulation System (CMS) Functions/Modes: Positioning Squeezing/trapping Others 0g 0 10
Choice of a force and geometry Thermophoretic velocity is independent of particle size and composition Thermophoresis does not contribute to particleparticle interaction Simplest geometry thermal capacitor Accepted geometry coaxial rings z Rejected forces: Electrostatic Magnetic Photophoretic Diffusiophoretic R 11
Choice of a force and geometry Thermophoretic velocity is independent of particle size and composition Thermophoresis does not contribute to particleparticle interaction Analog: Octopole electrodynamic balance (EDB) = Paul trap Simplest geometry thermal capacitor Accepted geometry coaxial rings z R F.Zheng, X.Qu and E.J.Davis. Rev. Sci. Instr. 72, 3380-3385, 2001 12
Thermoelectric ring module Tmax-Tmin=80K (at 2Hz) max dt/dt >500 K/s Trap Chamber Model Heat exchanger 13
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Scheme of approach for CMS development 15
Cloud Manipulation System(s): research opportunities 1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 16
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) 17
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) 18
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) Cooperative effects, streaming??? 19
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) 20
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) 21
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) z z R R 1.3. Cloud reshaping 22
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2.Trapping Mode: Dynamic balancing => Cloud squeezing!!! z z R R 23
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis Cloud Manipulation System(s): research opportunities b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2.Trapping Mode: Dynamic balancing => Cloud squeezing!!! v Mean (squeezing) velocity in ideal trap sq Particle number density growth: + 3t /τ n( t) dz = = τ dt = n(0) e 1 sq z sq Z-coordinate, mm a) 11.2 11.0 10.8 10.6 10.4 10.2 10.0 9.8 b) Excursion amplitude Secular (squeezing) velocity Beginning of the trajectory 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 time, s z 24 R
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Cloud Manipulation System(s): research opportunities Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability Direct observation p-p, p-c, c-c 25
1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Cloud Manipulation System(s): research opportunities Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability Direct observation p-p, p-c, c-c 2.2 Formation of extended clusters (too long for Brownian aggregation) 26
Cloud Manipulation System(s): research opportunities 1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability mm!!! Direct observation p-p, p-c, c-c 2.2 Formation of extended clusters (too long for Brownian aggregation) 2.3 Formation of gigantic clusters 27
Trapping mode: cloud squeezing 28
Cloud Manipulation System(s): research opportunities 1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability 3. Research Mode: 3.1. Fluid dynamics of heavy loaded cloud Periodic force Sharp profiles Synchronization with injection Direct observation p-p, p-c, c-c 2.2 Formation of extended clusters (too long for Brownian aggregation) 2.3 Formation of gigantic clusters 29
Cloud Manipulation System(s): research opportunities 1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability Direct observation p-p, p-c, c-c 2.2 Formation of extended clusters (too long for Brownian aggregation) 2.3 Formation of gigantic clusters +Q -Q 3. Research Mode: 3.1. Fluid dynamics of heavy loaded cloud Periodic force Sharp profiles Synchronization with injection 3.2. Electrostatic field Charge definition Space polarization Forced agglomeration 30
Cloud Manipulation System(s): research opportunities 1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability 3. Research Mode: 3.1. Fluid dynamics of heavy loaded cloud Periodic force Sharp profiles Synchronization with injection 3.2. Electrostatic force Charge definition Space polarization Forced agglomeration 3.3. Photophoretic manipulator (Poster session: von Borstel, I) Direct observation p-p, p-c, c-c 2.2 Formation of extended clusters (too long for Brownian aggregation) 2.3 Formation of gigantic clusters 31
Cloud Manipulation System(s): research opportunities 1. Positioning Mode (3D): 1.1. Keeps unperturbed cloud in the FOV => Brownian agglomeration experiments 1.2. Transportation to the area of detailed investigation a) High resolution optics b) Light scattering (Panel Optics: Levasseur-Regourd, A.C., Muños, O.) a) Thermophoresis b) Photophoresis (von Borstel, I) 1.3. Cloud reshaping 2. Trapping Mode: => Forced agglomeration experiments 2.1 Increases collision probability 3. Research Mode: 3.1. Fluid dynamics of heavy loaded cloud Periodic force Sharp profiles Synchronization with injection 3.2. Electrostatic force Charge definition Space polarization Forced agglomeration 3.3. Photophoretic manipulator (Poster session: von Borstel, I) 4.3. Combinations Direct observation p-p, p-c, c-c 2.2 Formation of extended clusters (too long for Brownian aggregation) 2.3 Formation of gigantic clusters 32
Acknowledgements European Space Agency PRODEX Program and Belgian Federal Science Policy Office. Bremen drop tower support company QinetiQ Space nv, Antwerp, Belgium SCTB NORD Company, Moscow, Russia 33
Analytical results 1Hz 2Hz 3Hz 5Hz 1 2 3 5 vsq mm/s 0.178 0.044 0.020 0.007 tau s 11 45 103 294 dz mm/s 3.20 0.80 0.35 0.13 time, s 40 35 30 25 20 15 10 5 0 Cloud squeezing time 1Hz 2Hz 3Hz 5Hz 0 20 40 60 80 100 compact agglomerate size, mm Amplitude excursion, mm 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 Peak to peak displacement 2Hz 3Hz 5Hz 0 20 40 60 80 100 compact agglomerate size, mm Velocity, mm/s 0.30 0.25 0.20 0.15 0.10 0.05 0.00 Squeezing and ThPh-BG velocities 2Hz 3Hz 5Hz 1 K/m 0.5 K/m 2 K/m 0 20 40 60 80 100 compact agglomerate size, µm 34
Electrodynamic balance does not work for clouds!!! 1g 0 2r 0 Potential V dc 2z 0 2R 0 V= V dc + V ac cosωt on both rings (r 0 << R 0 and z 0 ) 35