Seeing where energy goes can make n-fusion possible

New York: A new technology that “sees” where energy goes may bring scientists closer to realising nuclear fusion - a process that powers the Sun and other stars and has the potential to supply the world with limitless, clean energy.

Scientists and engineers from University of California (UC)-San Diego and defence consulting firm General Atomics have developed a novel technique to "see" where energy is delivered during a process called fast ignition, which is an approach to initiate nuclear fusion reactions using a high-intensity laser.

Visualising the energy flow enabled researchers to test different ways to improve energy delivery to the fuel target in their experiments. Scientists consider fast ignition a promising approach toward controlled nuclear fusion because it requires less energy than other approaches.

But in order for fast ignition to succeed, scientists need to overcome a big hurdle: how to direct energy from the high-intensity laser into the densest region of the fuel. To tackle this problem, the team devised a way to see, for the first time, where energy travels when the high-intensity laser hits the fuel target. The technique relies on the use of copper tracers inside the fuel capsule.

When the high-intensity laser beam is directed at the compressed fuel target, it generates high-energy electrons that hit the copper tracers and cause them to emit X-rays that scientists can image. After experimenting with different fuel target designs and laser configurations, researchers eventually achieved a record high (up to seven percent) efficiency of energy delivery from the high-intensity laser to the fuel.