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Sa-Lin Cheng Bernstein's third PowerPoint presentation

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Sa-Lin Cheng Bernstein's third PowerPoint presentation

  1. 1. Where Does the RealWhere Does the Real World MeetWorld Meet Superconductors?Superconductors? Saturday Morning PhysicsSaturday Morning Physics December 13, 2003December 13, 2003 Dr. Sa-Lin Cheng BernsteinDr. Sa-Lin Cheng Bernstein
  2. 2. Type I SuperconductorsType I Superconductors T H Hc Tc Phase Diagram Image courtesy: Joseph Bernstein © Akira Tonomura (Hitachi, Japan) Theory: BCS & Ginzburg-Landau
  3. 3. Type II SuperconductorType II Superconductor T H Hc1 Tc Phase Diagram Hc2 Image courtesy: Joseph Bernstein © Akira Tonomura (Hitachi, Japan) Theory: Abrikosove & Ginzburg-Landau
  4. 4. When applying currentWhen applying current Lorentz force pushes vortices (Flux motion)Lorentz force pushes vortices (Flux motion) Dissipation of energy Resistance Increase of temperature Quench!!!
  5. 5.  SuperconductingSuperconducting state:state:  T < TT < Tcc  H < HH < Hc2c2  J < JJ < Jcc Critical Surface Phase DiagramCritical Surface Phase Diagram
  6. 6. Vortex PinningVortex Pinning  To increase JcTo increase Jc  Artificial pinningArtificial pinning centers:centers:  How do vortices move?How do vortices move? – Avalanche vortex moviesAvalanche vortex movies – See first time (1993):See first time (1993): Akira Tonomura usingAkira Tonomura using transmission electrontransmission electron microscopemicroscope A. Bezryadin et al. © Phys. Rev. B 53, 8553 (1996)
  7. 7. http://www.howstuffworks.com/power.htm Power TransmissionPower Transmission  2001: Copenhagen, Denmark2001: Copenhagen, Denmark – high-temperature superconducting (HTS)high-temperature superconducting (HTS) – only 30 meters longonly 30 meters long  High cost!!High cost!!
  8. 8. Power Transmission in USAPower Transmission in USA  2001: Detroit, USA2001: Detroit, USA – Detroit Edison at the Frisbie SubstationDetroit Edison at the Frisbie Substation – three 400-foot HTS cablesthree 400-foot HTS cables – 100 million watts of power100 million watts of power http://www.ornl.gov/sci/fed/applied/htspa/cable.htm
  9. 9. Superconducting MagnetSuperconducting Magnet  Normal electromagnet:Normal electromagnet: 1 Tesla (= 10000 G)1 Tesla (= 10000 G)  Argonne bubbleArgonne bubble chamber:chamber: – Magnetic field = 1.8 TMagnetic field = 1.8 T – Alloy of niobium andAlloy of niobium and titanium (Nbtitanium (Nb33Ti wire)Ti wire) – Tc = 10 KTc = 10 K – Hc2 = 15 THc2 = 15 T © Argonne National Laboratory
  10. 10. Maglev TrainsMaglev Trains  ““Maglev”:Maglev”: MagMagneticnetic LevLevitationitation MLX01 http://www.rtri.or.jp/rd/maglev/html/english/maglev_frame_E.html
  11. 11. Working ModelWorking Model National Institute of Technology and Standards
  12. 12. How does it work?How does it work? http://www.acmaglev.com/technology.htm http://www.acmaglev.com/technology.htm © John Wiley & Sons, Inc. © John Wiley & Sons, Inc.
  13. 13. The Real DealThe Real Deal http://www.visionengineer.com 430 km/h = 267.2 mph
  14. 14. American MaglevAmerican Maglev  Atlanta ProjectAtlanta Project  Florida ProjectFlorida Project  Old Dominion University ProjectOld Dominion University Project  Virginia ProjectVirginia Project  Edgewater ProjectEdgewater Project  Charlotte ProjectCharlotte Project
  15. 15. MHD PropulsionMHD Propulsion  MHD =MHD = mmagnetoagnetohhydroydroddynamicynamic  First MHD ship: Yamato 1First MHD ship: Yamato 1 http://voyager55.cool.ne.jp/norimono/ship/public.html © John Wiley & Sons, Inc.
  16. 16. TevatronTevatron  19831983  Radius = 6.3 kmRadius = 6.3 km  1000 superconducting1000 superconducting magnets (Nbmagnets (Nb33Ti wires)Ti wires)  Protons + AntiprotonsProtons + Antiprotons  Energy = 1000 GeVEnergy = 1000 GeV (=1 TeV)(=1 TeV)  vv ~ 200 mph slower~ 200 mph slower than speed of lightthan speed of light
  17. 17. The Circular TrajectoryThe Circular Trajectory  F is directed toward theF is directed toward the center of the circular pathcenter of the circular path F v⊥ v v m B v qr = © John Wiley & Sons, Inc.
  18. 18. MRIMRI  Magnetic Resonance Imaging http://www.upstate.edu/mrilab/equipment/equipment.htm http://www.etch.com/mri.cfm
  19. 19. An ExampleAn Example  Human body: fat and waterHuman body: fat and water  Approximately 63% hydrogen atomsApproximately 63% hydrogen atoms  NMR signal from the hydrogen nucleiNMR signal from the hydrogen nuclei Image courtesy: Seth Blumberg
  20. 20. Spin of A ProtonSpin of A Proton  Can be thought of as a smallCan be thought of as a small magnetic fieldmagnetic field  Spin of a proton = ½Spin of a proton = ½  Spin of a hydrogen nucleus = ½Spin of a hydrogen nucleus = ½ http://www.cis.rit.edu/htbooks/mri/inside.htm P
  21. 21. Energy LevelsEnergy Levels Low energy state High energy state http://www.cis.rit.edu/htbooks/mri/inside.htm
  22. 22. TransitionsTransitions  The energy of the photon must exactlyThe energy of the photon must exactly match the energy difference between thematch the energy difference between the two statestwo states Frequency=f high lowE E E= − http://www.cis.rit.edu/htbooks/mri/inside.htm
  23. 23. Resonance FrequencyResonance Frequency  f = resonance frequencyf = resonance frequency E hf= Energy of photon Plank’s constant Frequency http://www.cis.rit.edu/htbooks/mri/inside.htm
  24. 24. Probe EnergyProbe Energy  B = magnetic fieldB = magnetic field  γγ = gyromagnetic ratio (H: 42.58 MHz/T)= gyromagnetic ratio (H: 42.58 MHz/T) f Bγ= E h Bγ= http://www.cis.rit.edu/htbooks/mri/inside.htm
  25. 25. Detect TumorsDetect Tumors  The signal in NMR spectroscopy: energyThe signal in NMR spectroscopy: energy difference (absorption & emission)difference (absorption & emission)  Raymond Damadian:Raymond Damadian: Nuclear magnetic relaxation times ofNuclear magnetic relaxation times of tissues and tumors differed (1971)tissues and tumors differed (1971)  Paul Lauterbur and Peter Mansfield:Paul Lauterbur and Peter Mansfield: 2003 Nobel Prize in Medicine2003 Nobel Prize in Medicine
  26. 26. SMESSMES  SSuperconductinguperconducting MMagneticagnetic EEnergynergy SStoragetorage http://www.epri.com/journal/details.asp?id=349
  27. 27. Neutron Stars (NS)Neutron Stars (NS)  Stellar corpses – result from collapse of massive star – big ball of neutrons (n) with some protons (p+) and electrons (e-)  What opposes gravity? – density so high, n, p+, e- packed as tightly as possible – degenerate matter supported by degeneracy pressure
  28. 28. Crab Nebula (M1) Here!
  29. 29. Cassiopeia-A: Image courtesy B. T. Koralesky, U. Minnesota Mono-frequency Radio Here!
  30. 30. NS Physical PropertiesNS Physical Properties PropertyProperty NSNS SunSun Mass [kg] 3.0 × 1030 2.0 × 1030 Radius [m]Radius [m] 1.0 × 1004 7.0 × 1008 Density [kg/Density [kg/m3 ] 7.2 × 1017 1.41.4 × 1003 Factor Different 1.5 1/70,000 500 Trillion g [m/sg [m/s22 ]] 2.02.0 × 1012 9.89.8 200 Billion world pop. in 1-cm3 box Object dropped from 1m has v ≈ 4.5×106 mph at surface
  31. 31. Orbit Near the SurfaceOrbit Near the Surface by Robert Nemiroff, Michigan Tech. Univ.
  32. 32.  Average density of NS is about 3 times the density of an atomic nucleus ⇒ nuclei dissolve into free n and p+  get n Cooper pairs and p+ Cooper pairs What’s Inside a NS?What’s Inside a NS? SUPERFLUI D! SUPERCONDUCTO R!
  33. 33. http://www.stormpages.com/swadhwa/stellarevolution/lecture20.htm Inside A Neutron StarInside A Neutron Star
  34. 34. Room-Temp. SuperconductivityRoom-Temp. Superconductivity  Carbon nanotubesCarbon nanotubes ? ? ?? ? ? Image: Dr Chris Ewels
  35. 35. AcknowledgementAcknowledgement  The audienceThe audience  Demo lab (Warren, Mark, and Harminder)Demo lab (Warren, Mark, and Harminder)  Prof. Franco NoriProf. Franco Nori  Seth BlumbergSeth Blumberg  Joseph BernsteinJoseph Bernstein

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