Fusion-power one step closer after a U.S. experiment successfully creates a fusion reaction in a U.S. Department of Energy laboratory. Although they were unable to reach their goal of ignition, the condition under which a fusion reaction would become self-sustaining and need no additional input, the team was able to successfully replicate the reaction that powers stars for a fraction of a second before the fuel canister blew itself apart, creating more energy than was spent for the first time during trials. The reaction was achieved by firing the worlds most powerful laser a small gold sphere which contained a capsule filled with deuterium and tritium, which are both hydrogen isotopes. As the laser energy passed through the gold container it released wide-angle x-rays, which compressed the isotopes under heat and pressure nearly as intense as that found in the heart of a star.
For just a moment the reaction was successful, the tritium and deuterium were compressed enough to create twice as much energy as they contained, about 150 gigabars, but only about 1 percent of the energy used by the laser. Lead author of the study Omar Hurricane expects that ignition can be achieved at around 300 gigabars, or roughly three hundred billion atmospheres of pressure, three hundred million times more pressure than found at the bottom of the sea. Although researchers are heading in the right direction and have brought fusion-power one step closer to reality, there are technical challenges to be overcome and a long way ahead. Chief among these is that the reaction must take place in a perfect sphere, something very difficult to accomplish due to the nature of isotopes under pressure. They want to escape the confines of the reaction and push very hard to get away, disturbing the shape needed and preventing ignition. Researchers are going to try to stop this from happening in their next attempt by changing the shape of the gold sphere to that of a gold rugby ball, still about the size of a pea.
Fusion power works in the opposite way as nuclear power. Instead of generating power via fission, splitting atoms apart, fusion crushes them together. This process is difficult to get started but once its going the reaction becomes self-sustaining, promising years of cheap, clean power without the risk of radioactive meltdown and without producing toxic by-products. Given the current balance in the world between needing inexpensive reliable electricity and not wanting to be vaporized in a nuclear holocaust, bringing fusion-power one step closer to a point where it can help the world is a very high priority across the globe. In 1997 the U.K. based Culham center used magnets to create a fusion reaction, and now 45 countries including the U.S. are pooling their resources to build a $20 billion ITER fusion reactor in France, which is scheduled to come online in 2020. whether ignition can be achieved through lasers or magnets is beside the point, but the promise of nearly limitless power that can easily be used the world over is an excellent reason to bend the laws of physics.
By Daniel O’Brien