Transports in Plasma Multi-Phase Matter System
Organized Session: Nov. 10th, 15:00am - 18:00am (JST)In a fusion reactor, high-temperature plasma must be maintained at a steady state to ensurea stable power supply. The main heating source is the fusion reaction in the central plasma. A
certain fraction of heat reaches the first wall, the divertor plate, causing damage to the device
wall material. Fusion power is generated by the fusion reaction of fuel particles, deuterium andtritium, but the burning efficiency is extremely low at a several percent of the fuel supplied.
Therefore, fusion reactor systems in steady-state operation require sophisticated control ofenergy and particle transport.
Thermal energy is converted from kinetic energy of plasma particles to light andelectromagnetic waves, which further interact with matter. Depending on their energy states,
materials circulating in the system undergo phase transitions to charged particles (plasma),neutral particles (gas), liquids, or solids. The purpose of this unit is to comprehensively
understand energy and particle transport across such multiple phase states, including theinteractions among the phases, and to establish a new picture of fusion reactor systems.
The purpose of this unit is to establish a new picture of fusion reactor systems bycomprehensively understanding energy and particle transport across such multiple phase states,
including the interactions among the phases.
In the transport of thermal energy, we focus on the effects of vibrational and rotational
states of molecules in the conversion between kinetic energy of charged particles, light andelectromagnetic waves via atomic and molecular processes, as well as on the role of thermal
instability in relation to the confining magnetic field geometry, on the dynamic response due tothe nonlinearity of atomic and molecular processes. Furthermore, by viewing these physics as
the interaction between light and matter, and delving into the interaction between theelectromagnetic field or momentum of light, the atomic nuclei and bound electrons in matter,
we aim to expand our research into areas, such as the formation of organic molecules in space(astrobiology) and plasma biotechnology.
For particle circulation, this is taken as "non-equilibrium cross transport".
Non-equilibrium cross transport here is synonymous with the non-equilibrium cross effect, inwhich multiple gradients are driven and coupled in a general sense, but it also includes themeaning that the flow of circulation with directionality is considered as a non-equilibrium flow
(transport), which is then driven by the cross transport. For example, in the case of plasma andneutral particles, the research will be conducted by considering both the control of plasma byneutral particles (micro) and the control of particle circulation by neutral gas (macro), eachfrom a bird's-eye viewpoint.
For the solid materials of the device wall of a fusion reactor, we will analyze the masstransfer phenomena between dissimilar materials such as copper alloy and the metal to bebonded with atomic-level precision, and elucidate the question "Why is a strong joint with very
few voids (high continuity) possible? from a microscopic viewpoint. The results obtained inthis research have potential for a wide range of engineering applications, including aerospaceand electronics fields.
These issues will be addressed through experiments in torus-type and linear magnetic fielddevices, and through simulations using fluid models, particle and kinetic models, and moleculardynamics methods.
In the invited lectures on the plasma-material interaction in a fusion device, physics inplasma, neutrals, and solid state in the boundary region of nuclear fusion device will addressedalong with the latest research results, in order to show how the interaction of various physicalprocesses such as solid state physics, atomic and molecular processes, and plasma transport canhelp us understand the phenomena observed in the region surrounding fusion devices.
In the invited lecture on light-matter interaction, the lecturer will give the basic physics
and properties of light using examples of various light production using synchrotron radiation
sources, as well as unresolved research issues in photon science. We will discuss the possibilityof new applications of photon science in the field of nuclear fusion, and the interdisciplinary
development in the interaction of light with various phase states, plasma, neutral particles,
liquid metals, and solid metals in a fusion reactor.
In the invited lecture on astrobiology, the lecturer will introduce the chemical and physicalprocesses that are important in the formation of organic molecules as an origin of life and anemergence of homochirality in the space. Historical background and the latest research resultsin the field are also given. Based on the lecture, common scientific principles between nuclear
fusion science and astrobiology, and interdisciplinary developments of both fields will bediscussed.

Figure 1. Example of light-matter interaction: Screw-shape protrusion called achiralnano-needle, developed through optical vortex laser irradiation to tantalum. The results havebeen obtained by a molecular dynamics simulation. (H. Nakamura et al. submitted to JJAP)