Institute of Laser Engineering of Osaka University;
Department of Earth and Space Science of the Graduate School of Science of Osaka University

Location: Institute of Laser Engineering, Suita campus

    Astrophysics explains the variety of astrophysical phenomena with the physics verified on the earth. However since the most of the astrophysical phenomena are those of transient, non-equilibrium, multi-hierarchy complex system which are realized under the extremely high energy density environments, sophisticated computer simulations are carried out in order to understand the mechanism. Recent development of high power lasers made it possible to simulate the astrophysical phenomena under the high energy density condition which has never been accessed in the laboratories and to verify the validity of those computer codes.
By realizing the extremely high temperatures, densities and intense fields in the laboratory utilizing the various high power lasers with international collaboration, we mimic the extreme
phenomena like the explosion in the Universe, meteor impact, and generate relativistic plasmas to study the internal state of planets, the physics of shock formation of SNR (super-nova remnant) and particle acceleration, and astrophysical nuclear synthesis under the MeV temperature and neutron-rich environment.


Mitsuo Nakai (Professor),
Youichi Sakawa (Associate professor),



Research areas

Collisionles shock, Magnetic reconnection, Plasma-jet collimation, Plasma instabilities, Particle acceleration using short-pulse high-power lasers, Relativistic magnetic field generation, Electron-positron pair production, Nuclear synthesis and excitation by bright gamma-ray flush, Experimental study on interior of Earth and Planets, and meteorite impacts with high-power laser, etc

Research themes

1. Astrophysical (Collisionless) shock and particle acceleration (Cosmic Ray acceleration):
At shock waves such as in Supernova Remnants, Active Galactic Nucleus, and Solar Fares, charged particles are accelerated up to the relativistic energy, and it is believed that these are sources of Cosmic Rays. We generate collisionless shock in laboratory using high-energy laser systems in the world, and study micro- and macro-structures of collisionless shock, physics of particle acceleration, magnetic field generation/amplification at shock, etc.

2. Experimental study on interior of Earth and Planets, and meteorite impacts with high-power laser:
High power laser can create ultrahigh pressure relevant to interior of Earth and planets, and ultrahigh-velocity conditions relevant to meteorite impacts. We have been trying to reveal the origin and evolution of Earth and planets with sophisticated diagnostics on these extreme conditions.

3. Nuclear science frontier cultivated by ultra-high intense lasers:
Extreme high energy density plasma provides a new experimental field for the nuclear science. We explore the nuclear synthesis under the astrophysical conditions by mimicking the hard radiation environment and high temperature plasma by utilizing ultra-high intense lasers.

4. We also study experimental research on Magnetic reconnection, Plasma-jet collimation, Hydro-dynamic instabilities such as Richtmyer-Meshkov and Kelvin-Helmholtz instabilities, Particle acceleration using high-power lasers, Relativistic magnetic field generation, Electron-positron pair generation, etc.