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Outflow jets, ion heating, and 3D structure in SSX

Outflow jets, ion heating, and 3D structure in SSX. Michael Brown Swarthmore College, NSF Center for Magnetic Self-Organization Tim Gray, Ed Dewey ’10, Bevan Gerber-Siff ’10, Kevin Labe ‘11 Vernon Chaplin ’07, Lake Bookman `08 M. J. Schaffer E. V. Belova

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Outflow jets, ion heating, and 3D structure in SSX

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  1. Outflow jets, ion heating, and 3D structure in SSX Michael Brown Swarthmore College, NSF Center for Magnetic Self-Organization Tim Gray, Ed Dewey ’10, Bevan Gerber-Siff ’10, Kevin Labe ‘11 Vernon Chaplin ’07, Lake Bookman `08 M. J. Schaffer E. V. Belova Research supported by US DOE and NSF

  2. SSX parameters

  3. Spheromak formation

  4. 2D MHD simulation

  5. Tangled 3D magnetic lines (lab and solar) 5 earth diameters tall one foot tall

  6. Reconnection geometry (2D model) Separatrix Current flow (out) Electron flow (in) Inflow (slow) Electron Diffusion Region Outflow (fast, Alfvenic)

  7. 3D hybrid simulation (Y. Lin) Kinetic ions (5x108 ions), fluid electrons

  8. Simulation results: 3D resistive MHD (E. Belova, PPPL)

  9. SSX device (distributed probe array) • Opposing magnetized plasma guns • Close fitting copper flux conserver • Midplane IDS access for flow studies

  10. Local 3D probe measurements Right-handed Spheromak Left-handed spheromak Reconnected poloidal flux

  11. Merging studies in prolate geometry • (2003-2007) • 0.4 meter diameter, 0.6 meter length • reconnection at midplane • formation of prolate FRC object • ultimately unstable with slow growth rate

  12. Counter-helicity merging (prolate)

  13. 3D probe measurements in SSX

  14. 3D probe measurements in SSX

  15. 3D probe measurements in SSX

  16. Bi-directional outflows in SSX High resolution ion Doppler spectroscopy (Cothran, et al, PRL to be submitted J. Fung thesis ‘06)

  17. Ion Doppler Spectroscopy (1.33m)

  18. Ion Doppler Spectroscopy (1.33m)

  19. Ion Doppler spectrometer layout

  20. IDS line shapes (high resolution)

  21. Observation of bi-directional outflow Data is effectively f(v_r)… one pixel is 10 km/s

  22. Stills from IDS movie Dynamics of the flow (bursts, turbulence) encoded in the lineshape

  23. Bi-directional outflows on the sun D. Innes (SOHO SUMER chromosphere) Innes, Nature, 1997 Innes, Solar Physics, 1997

  24. Location of SUMER slit on solar disk SiIV light dispersed along slit

  25. Velocity resolution 10 km/s Spatial resolution 1000 km Spatially localized events

  26. Hot ions in SSX Cothran, et al (SSX) (low density discharges, after glow discharge conditioning, short gas delay)

  27. Hot ions in SSX (merging)

  28. IDS hot ion temperature measurement (one shot, 1014 density)

  29. IDS hot ion flow measurement

  30. IDS hot ion temperature measurement (average, 5x1014 density)

  31. Scaling of Ti with density

  32. Scaling of Ti with density (single sph) Dipole-trapped, Gaussian fit, early in formation (30-40 ms)

  33. IDS ion temperature measurement HeII 468.57 nm (THe > TC)

  34. Te from CIII (97.7 nm) to CIV (155 nm) ratio

  35. Te from CIII (97.7 nm) to CIV (155 nm) ratio (single spheromak)

  36. Te from SXR array fitting Observe electron heating with SXR during 30-40 ms reconnection period

  37. Hot ions in the extended corona Cranmer, Space Science Rev, 2002 (UVCS)

  38. UVCS line of sight

  39. Greater than mass ratio ion temperatures

  40. Quadrupole measurement in SSX Mattheaus, et al, GRL (2005) Landreman, (2003) Cothran, et al, GRL (2003)

  41. Driven magnetic reconnection experiments Large slots cut into FC rear walls define the reconnection region 3D magnetic structure Energetic particles RGEAs Magnetic probe array Cothran et al GRL 30, 1213 (2003) Brown et al ApJL 577, 63 (2002) Brown et al Phys. Plasmas 9, 2077 (2002) Brown et al Phys. Plasmas 6, 1717 (1999) Kornack et al Phys. Rev. E 58, R36 (1998)

  42. 3D magnetic probe array 600 coils, 558 array ~2 cm spacing 25 three channel 8:1 multiplexer/integrator boards 10 eight channel 8-bit CAMAC digitizers Full probe readout every 0.8 s

  43. Quadrupole out-of-plane field Ion inertial scale 2 cm

  44. Trajectory of Polar spacecraft Path of tiny Polar

  45. Trajectory of POLAR spacecraft Polar trajectory Mozer, et al, PRL (2002)

  46. POLAR SUB-SOLAR OBSERVATION OF THE ION SCALE

  47. Merging studies in oblate geometry • (2007-2008+) • 0.5 meter diameter, 0.4 meter length • turbulent merging process • formation of oblate FRC object (sometimes) • Ti higher, Te lower than prolate • often unstable with Alfvenic growth rate

  48. Trapezoidal flux conserver in SSX

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