FUTI President, Prof. Masaaki Yamada Gives a Lecture, "A Future Energy Source, Nuclear Fusion, and Study of Plasmas in the Universe"

Dr. Masaaki Yamada

Dr. Masaaki Yamada

FUTI President, Prof. Masaaki Yamada gave a lecture titled “A Future Energy Source, Nuclear Fusion, and Study of Plasmas in the Universe” on March 11, 2016 at 6:30pm at the Nippon Club. Given the title, FUTI members and members of the alumni groups had anticipated a complex and difficult talk, but to our pleasant surprise the latest scientific discoveries were presented in a simple manner with the aid of beautiful photos and videos and had made the lecture very enjoyable.
Prof. Yamada who is a Distinguished Laboratory Research Fellow of the Princeton Plasma Physics Laboratory (PPPL), gave this lecture as a commemoration of his receiving the James Clerk Maxwell Prize for Plasma Physics in November 2015 (see the article in the FUTI Newsletter No. 14) in recognition “for fundamental experimental studies of magnetic reconnection relevant to space, astrophysical and fusion plasmas, and for pioneering contributions to the field of laboratory plasma astrophysics.”
As the day marked the fifth anniversary of the Great East Japan Earthquake, the lecture began with a moment of reflection for the victims, and a statement of resolve that science must make further advancements. The lecture proceeded with the following content.
When the temperature rises, all matter transform from solid mass to liquid to gas and then to plasma. When gaseous matter is heated further, the atoms are ionized where the positive ions and electrons are separated, forming bouncing plasma. Examples found in everyday life are mostly molecular gases such as with neon tubes and fire, but they can still be considered plasma because of the charged particles from electrons and ions that exist even in small amounts. The sun itself is full of hot plasma, from the explosive solar flares that arch out near sunspots, to coronas, the luminescent aura that surrounds the sun. Lightning also contain dense plasma. In fusion energy research, nuclear fusion is made inside high temperature plasma and is anticipated to be the dream source of energy.
Plasma experiments are 1) useful in nuclear fusion experiments, 2) helpful in comprehending the evolution of the universe, and 3) useful in explaining various phenomena with the Earth’s exosphere since it is made up of plasma.


Fig. 1: Galaxy outside of the Milky way

Normal matter (Baryonic Matter) made of protons and neutrons (also called Baryon) only occupy about 5 to 6% of matter which make up the universe while dark matter take up about 27% and dark energy about 68%. 90% of normal matter is in the state of plasma emitting light. Thus we can say most of visible universe is in plasma state. With the kind of small ratio of normal matter in the universe, one can say that the universe is mostly in its plasma state.


Fig. 2: Solar flares (Explosive ejection). While the sun rotates, solar winds generated by coronal mass ejection (CME) flows towards the earth changing their direction and then reconnect with the earth magnetic fields.

A mutual interaction is formed where charged particles flying around in plasma create an electromagnetic field while the electromagnetic field controls the activities in the plasma. This interaction of magnetic energy with thermal energy from the plasma (kinetic energy) results in Magnetic Reconnection. The lines of magnetic force are reconnected frequently in the corona which is the plasma atmosphere of the sun, changing the magnetic field energy to plasma particle energy. Therefore, it makes the plasma accelerate or heat up. This is thought to be the reason why the corona, the sun’s atmosphere, reaches about 1,000,000 degrees Celsius while the sun’s surface temperature is only about 6,000 degrees Celsius. In addition, because of the Magnetic Reconnection, the kinetic energy from the heated plasma overwhelms the sun’s gravitational force resulting in a solar wind.

Fig. 3. Interaction of solar winds with the earth magnetosphere. The interaction of solar winds with the earth magnetic field generates aurora phenomena.

Fig. 3: Interaction of solar winds with the earth magnetosphere. The interaction of solar winds with the earth magnetic field generates aurora phenomena.

The aurora which can be seen in the polar regions of the Earth is deeply rooted with Magnetic Reconnection. When a solar flare becomes active, the corona becomes active through Magnetic Reconnection and massive amounts of solar wind is directed toward the Earth. The solar wind reaches Earth in about two days carrying the magnetic line of force with it. This magnetic line of force interacts with the geomagnetism around the Earth and another Magnetic Reconnection occurs. This Magnetic Reconnection accelerates the plasma and increases the kinetic energy, colliding with the Earth’s atmospheric gases such as oxygen and nitrogen causing an electrical excitation and resulting in light emission. Without Magnetic Reconnection, the aurora will not happen.
At Princeton University, Magnetic Reconnection is artificially induced through the MRX (Magnetic Reconnection Experiment) of which Prof. Yamada is a pivotal leader. The MRX was established 20 years ago and since then there have been numerous important research results and papers published. Furthermore, an even bigger FLARE (Facility for Laboratory Reconnection Experiment) is currently being built with the support of the NSF (National Science Foundation) and part of the Princeton University’s multi-million dollar budget.
Nuclear fusion experiments have continued for decades as an ideal energy source, but it still has not reached practical use. Compared to the use of nuclear fission in nuclear reactors, radioactive pollution is far less and deuterium (a stable isotope of hydrogen with a mass approximately twice that of the usual isotope) used for fuel is contained abundantly in water. The reaction of deuterium+tritium becoming helium+neutron makes the mass slightly less allowing for the drawing out of fusion energy. In the beginning these experiments were a secret for each country, but after realizing difficulty in attaining practical use, experiments have been moving forward with international cooperation. The most promising donut-shaped device called the “Tokamak” gets its name from Russian. Even a company built on investments from venture capitalists called Tri Alpha Energy, Inc. has been established for further development. The most advanced program is the ITER (International Thermonuclear Experimental Reactor) in Southern France with Europe, Japan, Russia, U.S.A., China, and Korea investing billions of dollars, but it is still estimated to take several years until completion.
In conclusion, not only is plasma dynamic and beautiful, it is the key to solving the mysteries of the universe, the evolution of the universe, and cosmic research, and surely its research will gain even more importance in the field of astrophysics. Nuclear fusion encloses the hot plasma in a magnetic field but because the control by the magnetic field is highly chaotic, research becomes prolonged thus consuming a lot of time and research expenses, but the completion of such research will be monumental and beneficial to society and must be looked upon with patience and a long-term outlook. Eager and proactive participation from especially the younger generation would be much desired.

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