The quest for clean and affordable energy has proven, for the most part, a herculean task fraught with technical, practical, economic, and political difficulties, among others.
In the wake of climate change and the need to achieve sustainability, several alternatives have been sought to replace the almost ubiquitous fossil fuels and meet the projected global energy demand in the next half-century, which is expected to triple by 2050.
The burning of fossil fuels lies at the very root of many of the environmental problems that plague our world today, think about global warming/greenhouse effect and the attendant problems that accompany them.
Among these alternatives is the idea of “making stars on earth” by replicating in controlled conditions the phenomenon of nuclear fusion and following nature’s way of harnessing the resulting energy to generate power.
In other words, using the exact mechanism that the sun and other stars use in generating energy. After decades of coordinated efforts, physicists at the National Ignition Facility of the Lawrence Livermore National Laboratory in December, 2022, reported a break in the clouds when they achieved fusion ignition upon a scientific energy breakeven, i.e. when the energy extracted from the fusion reaction exceeded the driving laser energy.
What was the science behind this?
Nuclear fusion occurs when two light nuclei (e.g. Hydrogen) collide and combine to form a heavier one (e.g. Helium), releasing radiation energy in the process.
Since electrostatic repulsion exists between the two positively charged nuclei, an enormous amount of heat and pressure (comparable to that in the cores of the sun and stars) is required to overcome the resistance and activate the strong nuclear force that will hold them together. A big challenge, however, exists — it is often difficult to control such a reaction.
Two approaches have been invented to address this: Magnetic Confinement Fusion (MCF) and Inertial Confinement Fusion (ICF), also known as “laser fusion”.
The NIF works on the latter, and it is essentially the internal combustion approach to nuclear fusion energy. In laser fusion, a tiny pellet of deuterium-tritium (DT) isotopes (the fuel) is injected into a blast chamber and compressed to very high density (as high as 20 times that of lead) with an intense laser (192 lasers combined to give 2.05 MJ).
The high density (pressure) and compression heat (temperature of about 100 million degrees Celsius) induce the ignition of the thermonuclear explosion and the kinetic energy borne by reaction products (neutrons, X-rays, alpha particles) is then deposited as heat in a blanket serving as heat source in a steam thermal cycle to generate electricity.
The potential impact of this discovery on individual lives is multifaceted, ranging from the attainment of a higher quality of life through a cleaner environment (without the pollutive effects of fossil fuels and nuclear fission energy), lower energy costs (with prospects of providing abundant and relatively inexpensive energy), sustainable transportation (with electric vehicles powered by fusion-generated electricity), increased energy security (by reduced reliance on fossil fuels and imported energy), and even technological advancements in various industries, including healthcare and national security (ensuring the safety and reliability of nuclear weapons).
Ultimately, the deployment of fusion energy infrastructure and technologies would open up new frontiers for innovation across many disciplines and create job opportunities in engineering, construction, and maintenance, among others.
