Curriculum Vitae

Education

04/1995 - 03/1999	Faculty of Science, Kyoto University, Japan
04/1999 - 03/2001	Graduate School of Science, University of Tokyo, Japan (M. S.)
04/2001 - 03/2006	Graduate School of Science, University of Tokyo, Japan
07/2006	Ph. D. in Space Physics (Title: "High-energy particle acceleration and magnetic field dissipation in the plasma sheets of celestial magnetospheres", Advisor: Prof. M. Hoshino)

Employment

04/2003 - 03/2005	Research Fellowships for Young Scientists, Japan Society for the Promotion of Science
04/2005 - 03/2006	Software Engineer, Technology Division, Internet Initiative Japan Inc.
04/2006 - 03/2007	Researcher, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
11/2006 - 04/2007	Visiting Research Associate, NASA Goddard Space Flight Center (University of Maryland Baltimore County, Goddard Earth Sciences & Technology Center)
04/2007 - 04/2010	Postdoctoral Fellow, NASA Postdoctral Program at NASA Goddard Space Flight Center
00/2010 -	Postdoctoral Fellow, JSPS Fellowship for Research Abroad at NASA Goddard Space Flight Center

Research interests

Magnetic reconnection and its role in astrophysical plasmas.

• Relativistic magnetic reconnection (Papers 1-9, i)
  • Early works are overviewed by my review talk (PDF; 14.7MB) at Krakow Coneference (Oct. 2008).
• Magnetic reconnection (1-9, i-iv)
• Current sheet instabilities (2-5)
• Weibel instability (6)
• Collisionless shock
• Astrophysical jets (10)
• Kelvin-Helmholtz instability

• Particle-in-cell (PIC) simulation (1-7, i-iii)
• Relativistic fluid simulation (8-10)
• Relativistic magnetohydrodynamic (RMHD) simulation (10)
• Magnetohydrodynamic (MHD) simulation
• Parallel computing

Publications

Refereed Journals (First Author)

1. S. Zenitani and M. Hoshino (2001),
   "The Generation of Non-thermal Particles in Relativistic Magnetic Reconnection of Electron-Positron Plasmas",
   Astrophysical Journal, 562, L63-L66 (DOI, ADS)   errata
   • p.2, l.13 : "7.7 x 10² pairs per grid" → "7.4 x 10² pairs per grid" (Courtesy of Dr. C. Jaroschek)
   • p.4, l.3 : "synchrotron loss is not negligible" → "inverse Compton loss is not negligible"
2. S. Zenitani and M. Hoshino (2005a),
   "Relativistic Particle Acceleration in a Folded Current Sheet",
   Astrophysical Journal, 618, L111-L114 (DOI, ADS, arXiv)   errata
   • p.2, l.28 : "the antiparallel currents (±J_z) pull each other" → "... collide each other"
   • p.3, l.29 : "the half-wavelength of the RDKI (π/k_y)" → "the quarter wavelength of the RDKI (π/2k_y)" (corrected in the newer paper [2007 ApJ, 670, 702])
   • p.4, TABLE I : please ignore "L_x=1.0" and "L_y=1.0", because they are 2D simulation runs.
3. S. Zenitani and M. Hoshino (2005b),
   "Three Dimensional Evolution of a Relativistic Current Sheet: Triggering of Magnetic Reconnection by the Guide Field",
   Physical Review Letters, 95, 095001-095001-4 (DOI, ADS, arXiv)   errata
   • p.1, 3rd paragraph, l.13 : "... + n_bg exp(-ε/0.1T)" → "... exp(-ε/T)" (Courtesy of Dr. H. Takahashi)
   • p.4, 4th paragraph : "The most dominant RDKI has ..." → "... The most dominant RDKTI has ..."
   • fig.1, caption, l.2 : "... with color from blue (empty) to red ..." → "... with color from black (empty) to red ..."
   • We renamed the oblique mode (RDKTI) to the "relativistic drift-sausage-tearing instability" (RDSTI) in our newer paper (2008, ApJ, 677, 530) considering its properties.
4. S. Zenitani and M. Hoshino (2007),
   "Particle Acceleration and Magnetic Dissipation in Relativistic Current Sheet of Pair Plasmas",
   Astrophysical Journal, 670, 702-726 (DOI, ADS, arXiv)   errata
   • The online version and the arXiv preprint contain color figures.
   • p.702, l.1 : "an important large-scale processes" → "an important large-scale process"
   • p.710, 3.3, l.4 : "T_bg is always set to 0.1T" → "... is always set to T" (Courtesy of Dr. H. Takahashi)
   • p.711, Table 1 : inflow Alfven speeds (V_A^inflow) are wrong
   • p.722, eq.37 : "E = -v_e x B + ..." → "E = -(v_e/c) x B + ..."
   • p.722, Appendix. A, l.3 : "Jütter-Synge distribution" → "Jüttner-Synge distribution"
   • p.722, Appendix. A, l.4 : "Jütter-Synge gas" → "Jüttner-Synge gas"
5. S. Zenitani and M. Hoshino (2008),
   "The Role of the Guide Field in Relativistic Pair Plasma Reconnection",
   Astrophysical Journal, 677, 530-544 (DOI, ADS, arXiv)   errata
   • p.530, 3rd paragraph, l.11 : "a powerful acceleration engine (... Jaroschek et al. 2004a)" → "... Jaroschek et al. 2004b)" (Phys. Plasmas)
   • p.530, 3rd paragraph, l.l7 : "an index of -1 ~ -3 (... Jaroschek et al. 2004a)" → "... Jaroschek et al. 2004b)" (Phys. Plasmas)
   • p.530, 3rd paragraph, l.20 : "synchrotron radiation (Jaroschek et al. 2004b)" → "... Jaroschek et al. 2004a)" (Astrophys. J.)
   • p.531, section 2, l.15 : "T_bg/T = 0.1" → "T_bg/T = 1" (Courtesy of Dr. H. Takahashi)
   • p.541, Fig.12 : The sixth panel (2nd row; a=-0.5) is slightly broken. Please refer to the panel in the arXiv preprint.
6. S. Zenitani and M. Hesse (2008a),
   "The role of the Weibel instability at the reconnection jet front in relativistic pair plasma reconnection",
   Physics of Plasmas, 15, 022101-022101-10 (DOI, ADS, arXiv)   errata
   
   • "Erratum: The role of the Weibel instability at the reconnection jet front in relativistic pair plasma reconnection",
     Physics of Plasmas, 15, 089901 (DOI, ADS)
   • p.2, section 2, l.6 : "[-γ_β(ε-β_su_y)/T]" → "[-γ_β(ε-β_smcu_y)/T]"
   • p.2, section 2, l.19 : "T_bg/mc² = 0.1" → "T_bg/mc² = 1" (Courtesy of Dr. H. Takahashi)
7. S. Zenitani and M. Hesse (2008b),
   "Self-regulation of the Reconnecting Current Layer in Relativistic Pair Plasma Reconnection",
   Astrophysical Journal, 684, 1477-1485 (DOI, ADS, arXiv)   errata
   • p.1478, section 2, l.6 : "exp[-γ_β(ε-β_su_y)/T]" → "exp[-γ_β(ε-β_smcu_y)/T]"
   • p.1478, section 2, l.17 : "T_bg/mc² = 0.1" → "T_bg/mc² = 1" (Courtesy of Dr. H. Takahashi)
   • p.1478, TABLE 1 : &sigma_in would be corrected to 9, 2.4, 30, and 7.4, respectively
   • p.1479, 2nd paragraph, l.2 : "J_y=2d_cs<v_y>" → "J_y=2d_csq<v_y>"
   • p.1479, 2nd paragraph, l.10 : "|J|=2d_csc;" → "|J|=2d_csqc"
8. S. Zenitani, M. Hesse, and A. Klimas (2009a),
   "Two-fluid Magnetohydrodynamic Simulations of Relativistic Magnetic Reconnection",
   Astrophysical Journal, 696, 1385-1401 (DOI, ADS, arXiv)   errata
   • p.1387, equation 17 : "c_A = sqrt(...) " → "c_A = c sqrt(...)"
   • p.1397, Sec. 3.4 : Reynolds number R_M in this section is identical to Reynolds number S in Sec. 2.
   • p.1400, last sentence : "n [mc² + G(p/nmc²)]" → "nmc² [1 + G(p/nmc²)]"
9. S. Zenitani, M. Hesse, and A. Klimas (2009b),
   "Relativistic Two-fluid Simulations of Guide Field Magnetic Reconnection",
   Astrophysical Journal, 705, 907-913 (DOI, ADS, arXiv)  
10. S. Zenitani, M. Hesse, and A. Klimas (2009c),
    "Scaling of the Anomalous Boost in Relativistic Jet Boundary Layer",
    submitted to Astrophys. J.

Refereed Journals (Co-author)

1. M. Hesse and S. Zenitani (2007),
   "Dissipation in relativistic pair-plasma reconnection",
   Physics of Plasmas, 14, 112102-112102-8 (DOI, ADS)
2. A. Klimas, M. Hesse, and S. Zenitani (2008),
   "Particle-in-Cell Simulations of Collisionless Reconnection with Open Outflow Boundaries",
   Physics of Plasmas, 15, 082102-082102-9 (DOI, ADS)
3. M. Hesse, S. Zenitani, and A. Klimas (2008),
   "The structure of the Electron Outflow Jet in Collisionless Magnetic Reconnection",
   Physics of Plasmas, 15, 112102-112102-5 (DOI, ADS)
4. M. Hesse, S. Zenitani, M. Kuznetsova, and A. Klimas (2009),
   "A simple, analytical model of collisionless magnetic reconnection in a pair plasma",
   Physics of Plasmas, 16, 102106-102106-10 (DOI, ADS)

Conference Proceedings

• S. Zenitani and M. Hoshino, "A Plasma Sheet as a Source of Non-Thermal Particles Relativistic Magnetic Reconnection and Relativistic Drift Kink Instability in e-{+\-} Plasmas", 2003, Proceedings of the 28th International Cosmic Ray Conference, p.2043 (ADS)
• M. Hoshino, S. Zenitani, K. Nagata, and Y. Takagi, "Particle Acceleration in Kinetic Plasma Processes", 2006, Proceedings of Energy Budget in the High Energy Universe, p.108 (ADS)

Presentations at International Meetings

• "Generation of Non-thermal Particles through Magnetic Reconnection in case of Relativistic Magnetic Reconnection", The Eighth GEOTAIL SWG/Workshop, ISAS, Sagamihara, Japan, March 2001
• Fourth US-Japan Workshop on Magnetic Reconnection, Plasma Merging, Magnetic Jets (MR2002), Hakone, Japan, November 2002
• Fifth International Workshop on Nonlinear Waves and Chaos in Space Plasmas (NWW2003), Mumbai, India, March 2003
• "New Possible Mechanisms of High Energy Particle Acceleration in a Plasma Sheet", International Union of Geophysics and Geodesy (IUGG), Sapporo, Japan, July 2003
• "A Plasma Sheet as a Source of Non-Thermal Particles Relativistic Magnetic Reconnection and Relativistic Drift Kink Instability in e-{+\-} Plasmas", International Cosmic Ray Conference (ICRC), Tsukuba, Japan, August 2003
• "Magnetic reconnection in relativistic current sheets of pair plasmas", US-Japan Workshop on Magnetic Reconnection, Plasma Merging, and Magnetic Jets "Astrophysical Reconnection and Particle Acceleration" (MR2005), Awajishima Island, Japan, March 2005
• "The role of guide field in magnetic reconnection: the case of relativistic magnetic reconnection in pair plasmas", AGU fall meeting, San Francisco, USA, December 2006 (ADS)
• "Relativistic magnetic reconnection with a guide magnetic field", 8th International School/Symposium for Space Simulations, Kauai, Hawaii, USA, February 2007
• "Particle acceleration and magnetic dissipation processes in the plasma sheets of relativistic pair plasmas" US-Japan Workshop on Magnetic Reconnection, Plasma Merging, and Magnetic Jets (MR2007), Maryland, USA, March 2007 (invited),
• "On the current sheet thickness in relativistic pair plasma reconnection", Cambridge Workshop on Magnetic Reconnection, Maryland, USA, September 2007 (invited),
• "On the outflow region of relativistic pair plasma reconnection", Cambridge Workshop on Magnetic Reconnection, Maryland, USA, September 2007 (invited),
• "Self-regulation of the reconnecting current sheet in relativistic pair plasmas", AGU fall meeting, San Francisco, USA, December 2007 (ADS)
• "The role of the Weibel instability at the reconnection jet front in relativistic pair plasma reconnection", US-Japan Workshop on Magnetic Reconnection (MR2008), Okinawa, Japan, March 2008 (invited)
• "On the dissipation region in relativistic pair plasma reconnection", Japan Geophysical Union Meeting 2008, Chiba, Japan, May 2008
• "The role of the Weibel instability at the reconnection jet front in relativistic pair plasma reconnection", Japan Geophysical Union Meeting 2008, Chiba, Japan, May 2008
• "Current sheet expanding processes in relativistic pair plasma reconnection" Cambridge conference 2008, Bohn, Germany, August 2008 (invited)
• "Relativistic current sheets in electron-positron plasmas" Cracow conference 2008, Krakow, Poland, October 2008 (invited review) (PDF file)
• "The role of the Weibel instability at the reconnection jet front in relativistic pair plasma reconnection", Reconnection in Turbulent Fluid and its Implications Workshop, Krakow, Poland, October 2008 (PDF file)
• "Two-fluid MHD simulation of relativistic magnetic reconnection", AGU fall meeting, San Francisco, USA, December 2008 (ADS)
• "Relativistic two-fluid simulations of pair plasma reconnection", International Cambridge workshop on magnetic reconnection 2009, Fairbanks, Alaska, USA, August 2009 (invited)
• "Two-fluid simulations of relativistic magnetic reconnection in pair plasmas", 2009 US - Japan Workshop on Reconnection (MR2009), Madison, Wisconsin, USA, October 2009 (invited) (PDF file)
• "Relativistic two-fluid simulations of guide field magnetic reconnection", AGU fall meeting, San Francisco, USA, December 2009
• "Two-fluid Simulations of Relativistic Magnetic Reconnection in Pair Plasmas", 215th AAS meeting, Washington DC, USA, January 2010
• *TBD*, Yosemite Workshop, Yosemite, Feburary 2010 (invited)
• *TBD*, Dynamical Processes in Space Plasmas (Isradynamics 2010), Dead sea, Israel, April 2010 (invited)

Invited Talks in domestic meeting

1. "Instabilities in relativistic electron-positron plasmas", STE Simulation Symposium at Nagoya University, Nagoya, October 2002

Simulation Files

1. Relativistic magnetic reconnection
   • PIC simulation - particle acceleration (QuickTime movie; 14MB)
   • Two-fluid simulation - outflow evolution (QuickTime movie; 9.2MB)
   • Two-fluid simulation - Petschek outflow structure
   • Resistive RMHD simulation - Petschek-type current
2. Particle acceleration and fast field dissipation by the relativistic drift kink instability
   • PIC simulation (QuickTime movie; 19.5MB)
   • PIC simulation - field structure (Fig. 1 in 2005a paper)
   • Two-fluid simulation (QuickTime movie; 160KB)
3. 3D evolution of a relativistic current sheet
   • 3D snapshots (Fig. 1 from 2005b paper)
   • an oblique hybrid instability (Fig. 11 in 2008a paper)
4. The relativistic Weibel instability in relativistic magnetic reconnection
   • Out-of-plane field generation (QuickTime movie; 7.9MB)
   • Weibel-scattered particle trajectory (QuickTime movie; 19MB)
5. Ion distribution functions