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The Subaru Seminar is usually held in Room 104 of the Hilo Base Facility, adjacent to the main lobby. Everyone is welcome to attend. If you are interested in giving a seminar, please contact Subaru seminar organizers (Tadayuki Kodama, Nagayoshi Ohashi, Tomonori Usuda) by email : sseminar_at_subaru.naoj.org (please change"_at_" to @).

November 28, Wednesday, at 1:00 pm

" Laboratory Astrophysics Activities at ILE, Osaka University "

Hideaki Takabe

(Osaka University)


I have worked for Laser fusion for 20 years and devoted mainly on hydrodynamic instabilities and integrated code development for laser implosion physics [1]. Then, I was involved in the collaboration with supernova physicists to analyze the hydrodynamic instability of SN1987A. This led me to ``laboratory astrophysics'' to do a variety of model experiments on compressible hydrodynamics, atomic physics, plasma physics and so on the physics of which are expected to happen in the Universe. I aim at making plasma physics attractive for young scientists by providing challenging subjects of plasma physics in the laboratory astrophysics [2]. I am currently carrying out experiments of Astrophysics to model the structure formation of high Mach number collisionless shock observed in many supernova remnants, SNRs [3]. I demonstrated that the shock is formed by turbulent magnetic field produced by the nonlinear growth of the Weibel instability [4] in collaboration with about 20 groups in the world [5]. We will use the world-biggest laser NIF (National Ignition Facility) [6] for this experiment next year. In addition, I am working on the theory and computation of the vacuum breakdown [7]. Namely, at higher laser intensity about 1024 W/cm2 which is about two orders higher than the presently demonstrated one, we can efficiently convert laser energy to relativistic electron-positron plasma energy [8]. Such "plasma-QED physics" can model gamma-ray-burst, AGN jets, and many high-energy astrophysical phenomena. Finally it is noted that our activities are involved formally as Laboratory Astrophysics division (LAD) in AAS[9].

[Reference]

[1] H. Takabe, ``A historical perspective of developments in hydrodynamic instabilities, integrated codes and laboratory astrophysics'', Nuclear Fusion 44 S149-S170 (2004)
[2] H. Takabe, ``Astrophysics with Intense and Ultra-Intense Lasers``Laser Astrophysics'', Progress of Theoretical Physics Supplement 143, 202-265 (2001)
[3] TN Kato, H Takabe, ``Non-relativistic Collisionless Shocks in Unmagnetized Electron-Ion Plasmas'', Astrophysical Journal Letters 681 (2), L93 (2008)
[4] H. Takabe et al., ``High-Mach number collisionless shock and photo-ionized non-LTE plasma for laboratory astrophysics with intense lasers'', Plasma Physics and Controlled Fusion 50 (12), 124057 (2009)
[5] NL Kugland, ... H. Takabe and H. S. Park, ``Self-organized electromagnetic field structures in laser-produced counter-streaming plasmas'', Nature Physics, October 1 (2012)
[6] https://lasers.llnl.gov/
[7] Ruffini et al, Physics Reports 487, 1-140 (2010)
[8] C. P. Ridgers,Phys. Rev. Lett., 108, 165006 (2012)
[9] http://lad.aas.org/newsletter/newsletter_1_2012_09_10


Seminars are also held at JAC, CFHT, and IfA.



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