Essay: Overcoming the Obstacles to a Magnetic Fusion Power Plant

Fusion occurs when light nuclei combine to form heavier nuclei. The energy released in this process powers the stars and can provide humankind with a safe, sustainable, and clean source of baseload electricity, a valuable tool in the fight against climate change. To overcome the Coulomb repulsion of likecharged nuclei, fusion reactions necessitate temperatures of tens of millions of degrees or thermal energies of tens of keV, at which matter exists only in the form of plasma. Plasma is an ionized state of matter that is rare on Earth but characterizes most of the visible universe. The quest for fusion energy is thus intrinsically associated with plasma physics. In this Essay, I lay out my view of the challenges on the path to fusion power plants. As these need to be sizable and inevitably complex, large-scale collaborative enterprises are required, involving not only international cooperation but also private-public industrial partnerships. We focus on magnetic fusion, in particular on the tokamak configuration, relevant to the International Thermonuclear Experimental Reactor (ITER), the largest fusion device to be built in the world.