Science aims for first-ever controlled fusion reaction

Scientists are preparing for one of history’s largest and most important experiments: next year’s attempts to produce the world’s first controlled nuclear fusion reaction.

If successful, the experiment — set to take place at the US-based National Ignition Facility (NIF) — could lead to the development of a limitless new source of electricity for homes, businesses and industry. The experiment could also lead to new insights into the origins of the universe.

The American Chemical Society is exploring the possibilities raised by the experiment in a special two-day symposium this week titled, “Nuclear Diagnostics in Fusion Energy Research.”

Scientists have been trying to achieve controlled nuclear fusion for almost 50 years. Next year, researchers at the NIF at Lawrence Livermore National Laboratory in California will focus the energy of 192 giant laser beams onto a pea-sized target filled with hydrogen fuel. These lasers represent the world’s highest-energy laser system. The scientists hope that their effort will ignite, or fuse, the hydrogen atoms’ nuclei to trigger the high-energy reaction that powers the sun, stars and hydrogen bomb.

“Chemists will definitely play a role in determining whether nuclear fusion reactions have occurred during this NIF experiment, which is key to determining whether the experiment is a success,” says Dawn Shaughnessy, a scientist with Lawrence Livermore National Laboratory. “The idea is that the lasers will fuse hydrogen particles together, producing neutrons. We’ll collect and measure the materials produced from the ignition and hopefully be able to determine how many neutrons were made. More neutrons mean that more fusion has occurred.”

“A facility like this has never before been available to do experiments in nuclear chemistry,” added Richard Boyd, NIF science director and co-chair of the special ACS symposium. “We’re going where people have never gone before, and that could lead to some exciting, and possibly unanticipated, discoveries.”

The NIF building is ten stories tall and has the width of three football fields. The facility, which is 95 per cent complete, has taken more than a decade to build at an estimated cost of $3.5 billion. Next year, its 192 intense laser beams will deliver to its target more than 60 times as much energy as any previous laser system.

Scientists in the UK, France, Japan and China are also developing laser fusion facilities. The ones in France and China will be similar to NIF, but NIF will begin operating several years before the other two. The facilities in Japan and the UK will be less powerful than NIF; they will try to achieve fusion with a somewhat different technique than that used initially at NIF.

None of these facilities could produce a dangerous condition, Boyd said. As soon as the target’s fuel is expended — in just a few billionths of a second — the reaction stops, he said.