International Microgravity Plasma Facility John Goree The University of Iowa.

International Microgravity Plasma FacilityIMPFIMPF

International Microgravity Plasma Facility

John Goree The University of Iowa


plasma = electrons + ions Plasma

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What is a dusty plasma?

D

• Debye shielding

small particle of solid matter

• becomes negatively charged

• absorbs electrons and ions


Other names for Dusty Plasmas

• Complex plasmas (analogy to complex fluids)

• Fine-particle plasmas


Solar system• Rings of Saturn• Comet tails

Basic physics• Coulomb crystals• Waves

Manufacturing• Particle contamination

(Si wafer processing)

• Nanomaterial synthesis

Who cares about dusty plasmas?

International Microgravity Plasma FacilityIMPFIMPF9 0 9 1 9 2 9 3 9 4 9 5 9 6 9 7 9 8 9 9 *

*1999 publications are morenumerous than shown here.At the time this figure was prepareddata was available onlyfor Jan - Oct. 1999

0

80

160 9 months data in 1999

Rapid Growth of this Scientific Field:Dusty plasma publications

in APS & AIP journals


polymer microspheres

8 m diameter

Particles used in Basic Physics Experiments

separation a 0.5 mm

charge Q - 104 e


Forces Acting on a Particle

Coulomb

QE

Other forces:• Gas drag• Ion drag• Thermophoresis• Radiation Pressure

Gravity

mg


Electrostatic trapping of particles

Equipotentialcontours

electrode

electrode

positive

potential

electrode

electrode

With gravity, particles sediment to high-field region 2-D layer

Without gravity, particles fill 3-D volume

QE

mg


Gravity severe sedimentation

on Earth, 2-D experiments only

Microgravity enables 3-D experiments

Need for microgravity


• International Advisory Board formed

2000

• Pre-Development Phase B started

• DLR funds Phase A feasibility study

History of IMPF

1999

• Proposal to ESA by PI Greg Morfill

result: one of six rated excellent


13 members 13 members

9 countries9 countries

7 meetings 5/99 - 5/017 meetings 5/99 - 5/01

International Advisory Board for IMPF


Predecessor microgravity experiments

2000 - Mir Russian “High Energy Density Research Center”

1996-1998 Sounding rockets Morfill et al., PRL 1999


Predecessor microgravity experiments

PKE - Plasma Kristall Experiment

1999 - Parabolic flight tests

2000-01 - ISS• Feb. 2001 - launch• 2001 - the 1st physical sciences

experiment on ISS

PKE flight hardware with 1st & 3rd ISS crews


PKE vacuum chamber

insulator

ground

plasm a&

particles

ground

ground

rf electrode

fieldof

view

dust dispenser

Cameras for imaging

particles

Laser sheets for illuminating particles


PKE

Purpose:

Study 3D dusty plasmas:

– fundamental structure

– dynamics of melting and freezing phase transitions

Who:

Germany:

PI G. Morfill (Max-Planck Institute)

Russia:

High-Energy Density Research Center, Moscow

NASA-funded co-I: John Goree (U. of Iowa)


PKE timeline

2/26/01 Launched (Progress)

3/01 – 5/01 First experiments (40 hours)

10/01 Next series of experiments


PKE Results

particles

Crystal beginning to anneal

void


PKE - Results

Coalescence of two suspensions

(A sequence of video frames is shown here, as the plasma power was decreased)


Scope of IMPF Science Projects

Basic science:

• Melting

• Self-organization

• Waves

• Shocks

• Defect dynamics

• Few-body systems

• much more ...

Applications:

• Particle coating

• Nanoscale mfg.

• Particle growth


International AO

• Released Oct. 2000 by NASA, ESA, NASDA, CSA

• For Physical Sciences PI’s to use ISS instruments belonging to other countries

• 117 proposals were received (U.S. + Europe + Japan + Canada)

• The top 3 proposals (according to scientific merit in the peer review process) were from IMPF users


www.microgravity.netwww.microgravity.net

International Microgravity Plasma Facility John Goree The University of Iowa.

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