220 likes | 356 Views
IMPF. International Microgravity Plasma Facility. John Goree The University of Iowa. plasma = electrons + ions. small particle of solid matter. absorbs electrons and ions. becomes negatively charged. Debye shielding. What is a dusty plasma?. Other names for Dusty Plasmas.
E N D
IMPF International Microgravity Plasma Facility John Goree The University of Iowa
plasma = electrons + ions small particle of solid matter • absorbs electrons and ions • becomes negatively charged • Debye shielding What is a dusty plasma?
Other names for Dusty Plasmas • Complex plasmas (analogy to complex fluids) • Fine-particle plasmas
Solar system • Rings of Saturn • Comet tails • Manufacturing • Particle contamination • (Si wafer processing) • Nanomaterial synthesis • Basic physics • Coulomb crystals • Waves Who cares about dusty plasmas?
160 80 0 Rapid Growth of this Scientific Field:Dusty plasma publications in APS & AIP journals 9 months data in 1999
polymer microspheres » 8 mm diameter Particles used in Basic Physics Experiments • separation a» 0.5 mm • charge Q» - 104e
Forces Acting on a Particle Coulomb QE Gravity mg • Other forces: • Gas drag • Ion drag • Thermophoresis • Radiation Pressure
electrode Equipotential contours electrode Without gravity, particles fill 3-D volume positive potential QE With gravity, particles sediment to high-field region Þ2-D layer mg electrode electrode Electrostatic trapping of particles
Need for microgravity • GravityÞ severe sedimentation • Þ on Earth, 2-D experiments only • Microgravity enables 3-D experiments
1999 • Proposal to ESA by PI Greg Morfill • result: one of six rated excellent • DLR funds Phase A feasibility study • 2000 • Pre-Development Phase B started History of IMPF • International Advisory Board formed
International Advisory Board for IMPF 13 members 9 countries 7 meetings 5/99 - 5/01
1996-1998 Sounding rocketsMorfill et al., PRL 1999 • 2000 - Mir • Russian • “High Energy Density Research Center” Predecessor microgravity experiments
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 Predecessor microgravity experiments PKE - Plasma Kristall Experiment
Laser sheets for illuminating particles Cameras for imaging particles PKE vacuum chamber
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
Crystal beginning to anneal PKE Results particles 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
IMPF www.microgravity.net