Technique could be used to optimise laser-driven fusion

A new method for optimising the initiation of nuclear fusion reactions could mark a major step forward in the development of commercial fusion power, an international research group has claimed.

The team, led by scientists and engineers at the University of California, San Diego and General Atomics, developed a new technique to visualise where energy is delivered during a process called fast ignition, which is used to initiate laser-driven nuclear fusion.

Fast ignition involves two stages to start nuclear fusion. First, hundreds of lasers compress the fusion fuel (typically a mix of deuterium and tritium contained in a spherical plastic fuel capsule) to high density. Then, a high-intensity laser delivers energy to rapidly heat (ignite) the compressed fuel.

The technique is considered to be promising 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. "This has been a major research challenge since the idea of fast ignition was proposed," said Farhat Beg, professor of mechanical and aerospace engineering and director of the Center for Energy Research at UC San Diego.