複数のX-lineを形成する磁気リコネクションでの電子加速 / Elecron Acceleration during Magnetic Reconnection with multiple X-lines

96466365a9bf7e66990f2b9ba547b02f?s=47 Tsubasa Yumura
February 05, 2008

複数のX-lineを形成する磁気リコネクションでの電子加速 / Elecron Acceleration during Magnetic Reconnection with multiple X-lines

2008年度 修士論文発表会の発表資料
修士論文→ https://drive.google.com/open?id=0Bzb0bpXeRHYRWUptUEt3Ni11blk

96466365a9bf7e66990f2b9ba547b02f?s=128

Tsubasa Yumura

February 05, 2008
Tweet

Transcript

  1. 5.

    Ӊ஦ϓϥζϚதͷ࣓ؾϦίωΫγϣϯ 5 ଠཅίϩφϧʔϓ (NASA TRACE) ͔ʹ੕Ӣ (NASA Chandra, Hubble) ஍ٿ࣓ؾݍͱ

    GEOTAIL Ӵ੕ (JAXA) •  ଠཅ •  ࣓ؾݍڥքɾ࣓ؾݍඌ෦ •  ߴΤωϧΪʔఱମ •  Ӊ஦ϓϥζϚͷΤωϧΪʔ ։์ݱ৅ͱͯ͠ॏཁ
  2. 6.

    ࣓ؾϦίωΫγϣϯిࢠՃ଎ 6 •  ਓ޻Ӵ੕(GEOTAIL, Cluster ౳)ʹΑΔ஍ٿ࣓ؾݍͷͦͷ৔؍ ଌ •  γϛϡϨʔγϣϯʹΑΔՃ଎ϝΧχζϜղ໌ – 

    X-line ෇ۙͷ meandering/Speiser ӡಈ [Speiser, 1965] –  pileup ྖҬͰͷ ∇BυϦϑτ/࿷ۂυϦϑτ [Hoshino et al., 2001 JGR] •  ୯Ұͳ X-line Λ༩͑ΔγϛϡϨʔγϣϯϞσϧ͕ओྲྀ X-line pileup ྖҬ
  3. 7.

    ෳ਺ͷ X-line Λܗ੒͢ΔϦίωΫγϣϯ 7 Chen et al. (2007) ຊݚڀͷ໨త ෳ਺ͷ

    X-line Λܗ੒͢Δ࣓ؾϦίωΫ γϣϯͰͷిࢠՃ଎ϝΧχζϜΛղ໌͢Δ •  ஍ٿ࣓ؾݍඌ෦΍ଠཅ෩தͰ؍ଌ͞ΕΔ •  X-line ؒͷด࣓ͨ͡ྗઢɿ࣓ؾౡ –  ؍ଌɿ࣓ؾౡͱߴΤωϧΪʔిࢠ [Chen et al., 2007] –  ࣓ؾౡ͸߹ମ͢Δ [Finn and Kaw, 1977] –  γϛϡϨʔγϣϯɿ࣓ؾౡ߹ମͱిࢠՃ଎ [Saito and Sakai, 2006] ࣓ؾౡ X-line
  4. 10.

    ཻࢠγϛϡϨʔγϣϯ •  Maxwell ํఔࣜ •  ཻࢠͷӡಈํఔࣜ 10 ∇×B = cµ0

    J+ E /c ∇×E = ʵ B /c m v = q(E + v×B/cγ) m = γm0 γ = (1-v2/c2)-1/2 ཻࢠҠಈ F → v → x ిՙɾిྲྀີ౓ x → ρ, v → J Maxwell ํఔࣜ ρ, J → E , B ӡಈํఔࣜ E , B → F ɾ ɾ ɾ PIC (particle in-cell) ๏
  5. 11.

    γϛϡϨʔγϣϯઃఆ 11 ॳظ৚݅ɿHarris ܕిྲྀ૚ n(z) = n0 /cosh2(z/d) + n1

    Bx (z) = B0 tanh(z/d) Bx n z z 2 ࣍ݩγϛϡϨʔγϣϯ x z y Lx Lz Bx
  6. 13.

    ݁Ռɿ୯Ұͳ X-line Λ༩͑Δ৔߹ 13 ne /n0 0 1 48 24

    0 0 12 -12 x /λi z /λi ిࢠີ౓
  7. 14.

    ݁Ռɿෳ਺ͷ X-line Λ༩͑Δ৔߹ 14 ne /n0 0 1 48 24

    0 0 12 -12 x /λi z /λi ిࢠີ౓
  8. 16.

    ࣓ؾౡ߹ମͱిࢠՃ଎ 16 ࣓ؾதੑ໘ (z=0) Ͱͷిࢠີ౓ ΤωϧΪʔεϖΫτϧ ΤωϧΪʔɿε=γ-1 •  1ஈ֊໨߹ମ (8→2)

    ʹେ෯ʹΤωϧΪʔ૿Ճ •  ߹ମͷ߹͍ؒ(t=30ʙ34) ͸΄ͱΜͲΤωϧΪʔ૿Ճͳ͠ •  ిࢠՃ଎͸࣓ؾౡ߹ମʹରԠ͢Δ
  9. 17.

    ߴΤωϧΪʔిࢠͷۭؒ෼෍ <#> 17 0ɹɹ ɹɹ ɹ80 counts / cell Ωi

    T = 40 Ωi T = 20 Ωi T = 30 Ωi T = 10 ߴΤωϧΪʔ (ε > 1) ిࢠ਺ •  ୯Ұͳ X-line ͷ৔߹ɺ࣓ؾౡΛ ғΉϦϯάঢ়෼෍Λܗ੒ •  ઌߦݚڀͰ΋ಉ༷ͷߏ଄
  10. 18.

    ߴΤωϧΪʔిࢠͷۭؒ෼෍ 18 Ωi T = 20 Ωi T =30 Ωi

    T = 34 Ωi T = 38 0ɹ ɹ80 Counts / cell Ωi T = 40 Ωi T = 50 •  2 ஈ֊߹ମʹΑΓ̎ॏϦϯάঢ়෼෍Λܗ੒ ߴΤωϧΪʔ (ε > 1) ిࢠ਺
  11. 20.

    ࣓ؾౡ߹ମྖҬͰͷՃ଎ 20 Ωi T = 30 Ωi T = 34

    Ωi T = 38 •  ࣓ؾౡ߹ମྖҬͰΤωϧΪʔεϖΫτϧΛऔಘ •  ࣓ؾౡ߹ମ࣌ʹΤωϧΪʔ૿Ճ
  12. 21.

    ࣓ؾౡ߹ମྖҬͰͷՃ଎ 21 Ey Vey 0.0 2 -0.09 0 5 0

    -3 •  X-line ͱಉ༷ͷߏ଄ •  Ey ͰՃ଎ •  ࣓ؾౡ߹ମ࣌ʹܗ੒͢Δ X-line ͰՃ଎ -12 12 0 z x z y Vex Vey
  13. 22.

    Ճ଎ཻࢠ(ε>25)ͷيಓ 22 X-line ࣓ؾౡ߹ମ pileup energy - time energy -

    x z- x •  30ݸͷ௒ߴΤωϧΪʔ(ε>25)ిࢠͷཻࢠيಓΛௐ΂ͨ •  શͯͷిࢠ͸ X-line ͰՃ଎Λड͚ͨ •  ଟ͘ͷిࢠ͸ X-line ͷޙʹpileup ྖҬ and/or ࣓ؾౡ߹ ମྖҬͰՃ଎Λड͚͍ͯͨ ΤωϧΪʔɿε=γ-1
  14. 23.

    ໨࣍ 23 1. ং࿦ 2. γϛϡϨʔγϣϯ 3. Multiple X-line ͷޮՌ

    4. ύϥϝʔλઃఆґଘੑ – ܭࢉྖҬͷେ͖͞ґଘੑ 5. ݁࿦
  15. 24.

    ܭࢉྖҬͷେ͖͞ґଘੑ 24 ܭࢉ ܭࢉྖҬͷେ͖͞ Lx × Lz (λi) ॳظͷ࣓ؾౡα Πζ(λi)

    ॳظͷ࣓ؾౡ਺ ̍ 48 × 32 6 8 ̎ 24 × 32 6 4 ̏ 96 × 64 6 16 •  n ∝ ε-α ͰϑΟοςΟϯά
  16. 27.

    ݁࿦ •  ࣓ؾౡͷଟஈ֊߹ମʹΑΓߴΤωϧΪʔి ࢠ͸ଟॏϦϯά෼෍Λܗ੒͢Δɿ؍ଌ΁ͷد ༩ •  X-line ͱ pileup ྖҬʹՃ࣓͑ؾౡ߹ମྖҬ

    ΋ిࢠΛՃ଎͢Δɿ৽ͨͳཻࢠՃ଎ϝΧχζ Ϝ •  ௒ߴΤωϧΪʔిࢠͷੜ੒͸ෳ਺ͷՃ଎ྖ ҬʹΑΔଟஈ֊Ճ଎͕ॏཁ •  ϦίωΫγϣϯͷεέʔϧ֦େͱͱ΋ʹ࣓ 27
  17. 31.

    ܭࢉྖҬͷେ͖͞ґଘੑ •  X-line , pileup ྖҬɿ̎ഒ •  ࣓ؾౡ߹ମྖҬɿ̐ഒ •  ࣓ؾϦίωΫγϣϯͷεέʔϧ͕֦େ

    ͢Δͱ࣓ؾౡ߹ମྖҬͷد༩͕૿Ճ͢ Δɹ→ɹඇ೤తిࢠͷੜ੒ͷ૿Ճ 31 ܭࢉ̏ɹ96 × 64 ܭࢉ̍ɹ48 × 32
  18. 32.

    pileup ྖҬͰͷՃ଎ 32 •  pileup ྖҬ (|Bz| େ) Ͱڧ͍ Ey

    •  ∇B υϦϑτ •  ࿷ۂυϦϑτ ∇B v ∝ ʵB×∇B // ʵ y v ∝ ʵR×B // ʵ y x z y B R
  19. 33.

    ࣓ؾౡ߹ମ vs. SXL 33 run Mass Ratio Space(λi ) nm

    GF D(λi ) perturbation 1 100 48 × 32 8 0 0.5 GEM 2 100 48 × 32 8 0 0.5 GEM 3 100 48 × 32 SXL 0 0.5 Gaussian
  20. 34.

    ΨΠυ࣓৔ґଘੑ 34 run Mass Ratio Space(λi ) nm GF D(λi

    ) perturbation 1 100 48 × 32 8 0 0.5 GEM 5 100 48 × 32 8 0.5 0.5 GEM
  21. 35.

    ݁࿦ (2/2) •  ௒ߴΤωϧΪʔిࢠ͸ X-line ͰͷՃ଎ޙʹ pileup ྖҬ and/or ࣓ؾౡ߹ମྖҬͰ͞Β

    ʹՃ଎Λड͚ͯੜ੒͞ΕΔ •  ϦίωΫγϣϯͷεέʔϧͱͱ΋ʹ࣓ؾౡ ߹ମྖҬͰͷՃ଎͸ݦஶʹͳΓଟ਺ͷඇ೤ తిࢠΛੜ੒͢Δ 35