ASTR 2110

Nuclear fusion is a process that combines two light nuclei into a heavier one, releasing an enormous amount of energy. It has the potential to provide a clean, safe, and nearly limitless source of energy for humanity, without the environmental and safety concerns associated with nuclear fission.

There are two main approaches used by countries in the world as potential paths to sustainable nuclear fusion: magnetic confinement fusion (MCF) and inertial confinement fusion (ICF).

Magnetic confinement fusion involves confining the fusion fuel in a magnetic field, typically in the form of a torus-shaped chamber called a tokamak. The fuel is heated to millions of degrees Celsius, forming a plasma of ionized atoms, which are confined by the magnetic field to prevent contact with the walls of the chamber. This approach is the most widely studied and has made the most progress towards practical fusion power. China is currently focusing primarily on magnetic confinement fusion (MCF) in its research efforts towards controlled nuclear fusion. China’s main research facility for MCF is the Experimental Advanced Superconducting Tokamak (EAST), which has achieved a number of significant milestones in fusion research. China is also constructing its own fusion power plant, the HL-2M tokamak, which was expected to begin operation in 2021.

Inertial confinement fusion involves using lasers or particle beams to rapidly heat and compress a small target containing fusion fuel. This creates conditions of extreme temperature and pressure, causing the fuel to undergo nuclear fusion. This approach is more challenging due to the high laser power required and the difficulty of achieving the necessary levels of compression. The United States is currently focusing on inertial confinement fusion (ICF) rather than magnetic confinement fusion (MCF) in its research efforts towards controlled nuclear fusion. Recently, it was reported that the National Ignition Facility (NIF), for the first time achieved net energy gain, which refers to the ratio of the energy produced by the fusion reaction to the energy used to create the conditions for the reaction. In order for fusion to be a practical source of energy, the net energy gain must be greater than one, meaning that the energy produced by the reaction is greater than the energy used to initiate and sustain the reaction.