Front Line Research / Fusion Plasma Diagnostics and Advanced Plasma Confinement / Laboratories / QSE

Front Line Research
We conduct research into the properties of plasma heat and particle fluxes flowing into the divertor region utilizing our experimental device DT-ALPHA.

We aim for the clarification of the various phenomena that occur in the divertor region.

In nuclear fusion, an enormous amount of energy is generated when light nuclei collide with each other and form a heavy atomic nucleus in exchange for a slight loss in mass. A nuclear fusion reactor's purpose is to harness that energy as an energy source. However, since atomic nuclei have positive electric charges, they repel each other and do not bind together. Therefore, there is a need for provoking nuclear fusion by forming the nuclei into high-density plasma through heating them to high temperatures of 100 million degrees. But as there is no material on earth that withstands 100 million degrees, we made a strong magnetic field "basket" that confines plasma, provoking it to react. This is the basic principle of a nuclear fusion reactor.

When the outer most surface of the magnetic field "basket" contacts the reactor's metallic walls, the atoms of the wall are scraped away and mix with the plasma. The metallic atoms are known to cool the plasma temperature.

The device that prevents the outer most surface of the magnetic field "basket" from contacting the reactor walls is called a divertor. At the Tobita Laboratory, we conduct research into clarifying the various phenomena that occur in the divertor region.

The DT-ALPHA, a nuclear fusion reactor divertor simulator

Plasma ejected from the DT-ALPHA

We are conducting simulated experiments on a nuclear fusion reactor's divertor.

A divertor plate is exposed to very high heat and particle fluxes diverted from a core plasma. Therefore, as well as the development of materials for a diverter plate that can withstand conditions in a severe environment, how to attenuate plasma's heat and particle flux is current issue. To resolve the issue, first, there is a need to explore properties of the plasma near the divertor.

To simulate the plasma flow that contains high-energy particles, we have developed our own small simulator called DT-ALPHA by combining a linear high-density plasma source and an ion beam injection device. We are currently focusing on methods that will convert plasma and particle energy into light energy and attenuate these, and our research is progressing based on the data that we have derived from our DT-ALPHA experiments.

This laboratory's research does not only focus on technical contributions to a nuclear fusion power plant that may be ready for practical use by the latter half of the 21st century; our research also aims for the establishment of basic physics related to the overall peaceful usage of nuclear fusion technology.

A conceptual rendering of a nuclear fusion reactor's structure

The ITER, a tokamak-type international thermonuclear experimental reactor under construction

Energy Physics Engineering Fusion Plasma Diagnostics and Advanced Plasma Confinement

Front Line Research We conduct research into the properties of plasma heat and particle fluxes flowing into the divertor region utilizing our experimental device DT-ALPHA.

We aim for the clarification of the various phenomena that occur in the divertor region.

We are conducting simulated experiments on a nuclear fusion reactor's divertor.

Laboratories

Energy Physics Engineering
Fusion Plasma Diagnostics and Advanced Plasma Confinement

Front Line Research
We conduct research into the properties of plasma heat and particle fluxes flowing into the divertor region utilizing our experimental device DT-ALPHA.