Facts of the Matter: Scientists are inching closer to creating fusion reactions

Thermonuclear reactions deep in the sun’s interior consistently generate the same amount of energy as 2.5 billion 500-megawatt generators, the largest on Earth. In one short second the sun produces enough energy to power New York City for 100 years.

Insanely hot, fusion reactions are thermonuclear (thermo=temperature) because they take place at temperatures in the millions of degrees. The pressure is also unimaginably high in the star’s core as the gravity from the star’s immense mass contains the hot plasma and prevents the star from expanding.

All stars exist in a quid pro quo state of equilibrium. Gravity prevents the star from exploding, while fusion in the core prevents gravity from crushing it.

In order for fusion to occur, two hydrogen ions must collide with just the right dynamics for the strong nuclear force to overcome the repulsive electric force.

This initiates what is arguably the most important process in the universe, when fusion begins the creation of heavier elements, nucleosynthesis.

Hydrogen ions are just protons with electrons stripped off. In the plasma state, electrons are too energetic for the nuclei to hold them, so the plasma is actually a sea of free protons and electrons.

The beauty of fusion is that when you weigh the atomic nuclei before and after, they do not add up. The helium nucleus weighs less than the protons that created it by less than 1%. The excess mass is released in the form of energy according to Einstein’s mass-energy equivalence, E=mc2.

Each fusion produces a very small amount of energy. Yet, because of its tremendous size, the sun produces 35,000 times more energy than all electricity used on Earth as about 4 million tons of the sun vanishes every second!

Scientists and technologists would like to re-create the conditions in a fusion reactor on Earth to generate electricity.

Fusion power sounds too good to be true. It uses deuterium, or heavy hydrogen, which is plentiful in Earth’s oceans where there is enough to power the entire planet for a million years. It is clean. There is no nuclear waste, only helium, which is a commercially viable product and a diminishing resource on Earth.

The keys to commercially producing large amounts of fusion energy are to have a large number of protons in the plasma, to have the most optimal configuration of protons to maximize fusion, and to have the temperature and pressure high enough to force protons to fuse.

Containment of the fusion process at the millions of degrees required is extremely difficult. It is not a problem in the sun where gravity supplies the pressure, which creates the heat. On Earth, however, there is no substance that can withstand those temperatures and pressures.

Of all containment solutions tried to date, magnetic fields have shown the most promise. Several types of toroidal (doughnut-shaped) confinement systems have shown promise.

Although a scalable fusion reactor is uncomplicated in description, engineers are still working to build one, after 70 years of being “only 50 years away.”

As promising as it sounds, virtually all attempts to generate more power than is used for the equipment have failed until this week. An announcement from Lawrence Livermore National Laboratory stated that a small positive output had been achieved. Even though it is too small to upscale immediately, those who know it consider it an extremely positive step toward a workable, carbon-free and chemical-free energy source.

“Simply put, this is one of the most impressive scientific feats of the 21st century,” U.S. Energy Secretary Jennifer Granholm said at a Washington, D.C., media briefing.

Many skeptics say we will never get a working fusion reactor because the containment problem is insurmountable. Others look to the future as a solution to Earth’s energy problem with no carbon or radioactive waste to worry about.