A Donut Hotter Than The Sun
Imagine you are lost in the wilderness, and desperately need to start a fire in order to survive. You tirelessly rub two sticks together, but the process is arduous and wastes your precious energy. You then have a pivotal realization: you can harness the sun’s natural light to spawn a fire using a magnifying glass. This simple, energy-efficient discovery proves crucial to your survival. Analogously, scientists from the United States, Russia, Korea, Japan, China, and the EU seek to harness the product of fusion reactions, which naturally occur in the sun, to produce limitless, green energy (ITER 2014).
Construction of the International Thermonuclear Experimental Reactor (ITER) is currently underway in the South of France, and in anticipation, scientists like William and Mary’s Saskia Mordijck are dedicating themselves to the theoretical work and modeling that are fundamental to the successful execution of the ITER project (Ikeda, 2013). The target completion date for the reactor is 2020, just around the corner in the timescale of nuclear energy.
Fusion occurs in the core of the sun at 15 million degrees Celsius when two hydrogen atoms fuse into a heavier element, helium, and release superabundant energy as heat. Physicists face a unique challenge when replicating the reaction on earth: containing the scorching reaction in a vessel without melting the walls. They have solved this problem with magnets that mimic the gravitational forces holding the sun together. These magnets redirect particles’ movement, preventing their escape. The ITER reaction vessel, called a Tokamak, will be in the shape of a donut, and have a core temperature 100 times hotter than the sun. At this extreme temperature, the electrons (negatively charged particles orbiting each hydrogen atom) are stripped away, and the contents of the Tokamak change from a gas to a fluid-like plasma (EFDA 2014). Neutral particles created as a byproduct of the fusion reaction, called neutrons, are unaffected by the magnets, and freely interact with the walls, exchanging heat. This energy source could ultimately supply power plants with abundant electricity. The most compelling aspect of nuclear energy is how little is required to generate the necessary heat. Just a few grams of seawater could supply megawatts of energy. That’s enough to power a small city. The project is exciting for the international community, but due to the 13 billion dollar price tag, the United States has reallocated funds away from domestic fusion research. According to Mordijck, this harms the scientific infrastructure that will be needed to utilize the knowledge gained by ITER, and hampers the cultivation of future fusion researchers in the university setting.
Fusion energy has the potential to become a key solution to the impending energy problem, with the right support. Fission, the currently used form of nuclear energy, has been catastrophic in cases such as Chernobyl, and has wrongfully tarnished the reputation of nuclear energy as a whole. Fission breaks atoms apart, and can cause an uncontrollable domino effect of cascading reactions. Such overeager reactions are not a risk with fusion, which forces two atoms to coalesce against their will by purposefully subjecting them to extreme conditions.
Mordijck feels that everyone should care about fusion energy, and is actively working to make this technology, which seems perpetually out of reach, a reality. She contends that this is the safe, reliable solution we need to meet the energy demands of the future. Mordijck uses theoretical physics to model particle behavior in the plasma, which is crucial for optimizing energy efficiency and output, and is a key component to making fusion energy a reality (Lauber, 2013). She seeks to understand what controls the transport of particles in plasma, which diffuse much like perfume through the air. Mordijck admittedly loves the science, but distinguishes science for science’s sake from science for progress, and decidedly believes in the latter. She hopes to educate the next generation of nuclear physicists, and to utilize the interdisciplinary nature of William and Mary to make progress in all aspects of fusion energy: not only physics, but also public policy, economics, law, government, and environmental studies.
Supportive efforts are not limited to the academic realm. There is a role for active citizens to support this potentially prolific energy resource as well, since public opinion about fusion energy impacts policy. Inextricably intertwined with their excitement about the recent 200 million dollar contribution of the United States to ITER, domestic fusion researchers have lobbied to save their personal research in recent years. Efforts to educate congressmen about the importance of their work were largely successful, although funding still took an appreciable hit. Mordijck hopes that by disseminating knowledge about the safety and abundant potential of fusion energy, the research community and the public can work together to encourage exclusive reliance on sustainable energy resources. If the completed ITER Tokamak meets researchers’ expectations, it could prove to be the magnifying glass of survival in a world with increasing energy demands: it is low risk, reliable, offers remarkable output with little input, and harnesses the brilliant simplicity of the sun’s natural processes to generate bounteous, clean energy.
* This story was written as part of a course in the Environmental Science & Policy program at the College of William & Mary, ENSP 249: Science Communication. For more information on the course, please email the course instructor, Dr. Ibes at dcibes@wm.edu.
Sources
"Fusion: Tokamaks." EFDA. http://www.efda.org/fusion/fusion-machine/types-of-fusion-machines/tokamaks/ (accessed February 5, 2014).
Ikeda, K. "Progress In The ITER Physics Basis." Nuclear Fusion 47, no. 6 (2007). http://dx.doi.org/10.1088/0029-5515/47/6/E01 (accessed February 6, 2013). ITER Organization. "ITER: the world's largest tokamak."
ITER: the way to new energy. http://www.iter.org/mach (accessed February 5, 2014)
Lauber, Phillip. "Superthermal particles in hot plasmas - kinetic models, numerical solution strategies, and comparison to Tokamak experiments." Physics Reports 533, no. 2 (2013): 33-68. http://www.sciencedirect.com/science/article/pii/S0370157313002676 (accessed February 5, 2013)
Mordijck, S., Research Assistant Professor, College of William and Mary. mordijck@cs.wm.edu, 757-221-3463. Personal communication, in-person interview, January 30, 2014 YouTube. "Meet the Innovators: Saskia Mordijck."
YouTube. http://www.youtube.com/watch?v=yTAgt1NRSi0 (accessed February 5, 2014).
