NUCLEAR FUSION: SMALL STEP OR BIG LEAP?

NUCLEAR FUSION MIGHT FINALLY BE WITHIN OUR GRASP

There’s a lot at stake

THERE HAS BEEN A LOT OF HYPE OVER RECENT RESULTS FROM THE UNITED KINGDOM'S Joint EuropeanTorus (JET) FACILITY, SUGGESTING THAT THE DREAM OF NUCLEAR FUSION POWER IS GETTING CLOSER. Fusion is shown to operate because it is the mechanism that drives the Sun, which provides heat and light to the Earth. However, making the move from scientific laboratory tests to long-term electricity production has proven challenging for decades.

Fusion's primary goal is to bring atomic nuclei together to form a new, heavier nucleus while simultaneously releasing energy. This differs from nuclear fission, which involves splitting a heavy nucleus like uranium into smaller ones while simultaneously releasing energy.

The process of fusing light atoms, such as hydrogen or helium isotopes, together has proven to be a substantial challenge. Because they are electrically charged and repel each other, they won't fuse until the nuclei are travelling fast enough to get physically close to each other, which would necessitate severe circumstances. Because of its massive gravitational fields and massive bulk, the Sun achieves this in its core.

"Inertial confinement," in which a tiny fusion fuel pellet roughly one-tenth of a centimeter in diameter is heated and compressed from the outside using laser radiation, is one method utilized in labs on Earth.

In recent years, some positive progress has been made on this approach, possibly most notably by the National Ignition Facility in the United States, which announced a 1.3 million Joules (an energy measurement) fusion yield last year. While this generated 10 quadrillion Watts of power, it only lasted a fraction of a second (90 trillionths).

Another technique, known as "magnetic confinement," has been widely used in laboratories throughout the world and is regarded to be one of the most promising paths to future fusion power units.

It entails the use of fusion fuel in the form of a hot plasma, which is a cloud of charged particles confined by strong magnetic fields. The confinement mechanism must retain the fuel at the proper temperature and density for an extended period of time in order to create the conditions for fusion reactions to occur.

This is where a major portion of the issue rests. The small amount of fusion fuel (usually just a few grams) must be heated to enormous temperatures, on the order of ten times that of the Sun's core (150 million degrees Celsius). And all of this must happen while remaining confined in a magnetic cage in order to maintain an energy output.

Various machines can be used to try to keep the plasma magnetically contained, but the most successful to date is the so-called "tokamak" design, which confines the plasma using a torus (doughnut shape) and complicated magnetic fields, as utilised at the JET facility.

NUCLEAR FUSION: SMALL STEP OR BIG LEAP?

The current findings are a significant step forward in the search for fusion energy. The entire energy output of 59 million Joules over a five-second period resulted in an average fusion power of roughly 11 million Watts.

Even while this is only enough to heat roughly 60 kettles, it is nevertheless noteworthy, as it produces 2.5 times the previous record, achieved in 1997. (Also at the JET facility, achieving 22 million Joules).

Years of planning and a highly skilled team of dedicated scientists and engineers have culminated in JET's achievement. JET is currently the world's largest tokamak and the only one that can use both deuterium and tritium as fuel (both isotopes of hydrogen).

Because of the machine's construction, which includes copper magnets that heat up quickly, it can only operate with plasma bursts of up to a few seconds. Superconducting magnets will be required to make the transition to longer-term, high-power operations.

Fortunately, this is the situation at the ITER project, which is already 80 percent complete and is being built in the south of France as part of a 35-nation multinational effort. The ITER machine design, likewise a magnetic confinement device, is expected to produce 500 million Watts of fusion power, and the latest results have given tremendous confidence in the engineering design and physics performance.

However, there are still significant obstacles to overcome. These include creating adequate robust materials that can endure the machine's tremendous pressure, handling the massive power output, and, most crucially, providing energy that is economically competitive with other kinds of energy generation.

For decades, achieving significant power outputs and maintaining them for longer than extremely brief durations has been a serious difficulty in fusion. An eventual fusion powerplant simply cannot be made to work unless this problem is solved. As a result, the JET results are an important milestone, even if they are only a first step.

Scaling up present fusion successes in following fusion systems, such as ITER, and then in demonstration power plants beyond that, will be the huge leap. And it should be possible to achieve this in the not-too-distant future, with a target date of operation in the 2050s or potentially even earlier.

CRUCIAL BENEFITS

There's a lot on the line. Fusion generates more energy per gramme of fuel than any other method now available on Earth. Fusion has a number of advantages, including the production of helium and neutrons (particles that make up the atomic nucleus alongside protons), as well as the absence of carbon dioxide or other greenhouse gases.

Deuterium, which may be found in saltwater, and lithium, which is similarly abundant and found in large salt flats, are the basic fuels. The amount of fusion energy generated by a laptop battery and a bathtub of water is believed to be roughly 40 tonnes of coal.

The materials that make up the reactor do produce some radioactivity. However, it is unlikely to be as long-lasting or intense as the radioactive waste created by nuclear fission, making it a potentially safer and more appealing option than conventional nuclear power.

At the end of the day, Rome was not constructed in a day. Various other facets of human creativity, like as aviation, have traditionally taken a long time to come to maturity. That means that small steps forward are tremendously important and should be cherished.

Fusion is crawling forward inexorably, and we're coming closer to realizing that once-fanciful ideal of commercial fusion power. It will one day provide a virtually unlimited supply of low-carbon energy for many future generations. So, while it isn't there yet, it is on its way.