Complex Plasma Systems
Advanced Energy Generation Division Complex Plasma Systems Research Section
Associate Professor : Takashi MINAMI
Associate Professor : Shinichiro KADO
Assistant Professor : Shinsuke OHSHIMA
Professor (Concurrent) : Kazunobu NAGASAKI
Investigating complex properties in high-temperature plasmas in Heliotron J device based on the various plasma diagnostic and analysis techniques
Controlled thermonuclear fusion energy is regarded as one of the promising future base load power plants from the viewpoints of resource abundance, less environmental load and nuclear proliferation resistance. Its realization relies on the investigation of high-temperature, high-density magnetized plasma confinement. The research of plasma - the fourth state of matter - includes its feature of collective particles of electrons and ions in motion and its feature of magneto-fluid. Energy distribution of the particles or the orbit in the magnetic field will be a key issue in the former case, while the treatment of instability and turbulence will be a key in the latter case. In our laboratory, we are investigating such a complex plasma behavior in Heliotron J, a helical plasma confinement device, by means of various kinds of diagnostics or simulations. For the purpose of achieving better plasma particle and energy confinements, "plasma control schemes", such as magnetic configurations, heating conditions and fueling scenarios, are being investigated
Probing What Is Real in Plasma Using Optical Emission
Optical emission from plasmas includes plenty of information such as density, temperature, ionic species and their fluctuations.
"Know the enemy (plasma) and know yourself (measurement methods and data), then you can fight the hundred battles without fear" --the real plasma properties that have
never been known to anyone will be in our hands.
Plasma emits various line spectra as can be seen through a simple grating film. One can draw huge amount of information from the
Temperature and density diagnostic for super-high temperature plasma using the latest laser and optical technologies
Plasma exists over wide scale range from super-low to super- high temperature and density. If you can know the exact density and temperature, you can know the real plasma properties. We are developing the Nd:YAG laser Thomson scattering diagnostic system based on the latest laser and optical technologies. We will explore the world of over-100-million-degree temperature plasmas into which any diagnostic instruments cannot be inserted.
Nd:YAG laser Thomson scattering system installed in Heliotron J
Characterization of Plasma Turbulence Based on Spectral Analysis
Confined plasma is, in reality, far from calm. There are many types of turbulent fluctuations growing from the non-uniform plasma parameters. They enhance the transport and degrade the plasma confinement property. For the characterization of the turbulence, we applied various kind of spatiotemporal spectral analysis methods and trying to figure out the correlation between the turbulence and the plasma confinement.
Measurement and signal processing for the turbulent plasma fluctuations. Various spectral analysis techniques are useful for determining the eddy size, frequency and non-linear coupling of the turbulences.