Scientists propose that a new ultra-powerful laser that could heat materials to temperatures hotter than the sun almost instantaneously might lead to a breakthrough in fusion energy production.
Theoretical physicists at the Imperial College London in the United Kingdom propose a heating technique that could take advantage of high-intensity lasers' ability to generate "electrostatic shockwaves" which, in the proper material, can heat up the ions in the material directly.
When existing lasers heat up a material, they heat up the electrons in the material first, then they heat up the ions — a process that slows the heating.
Such high-intensity laser, if it could be built, could heat atoms at a rate 100 times faster than achieved in current fusion experiments. It would bring materials to more than 10 million degrees Celsius in less than a millionth of a second.
Computer modeling suggests that a material with appropriate combinations of ions would see the electrostatic shock waves heat up those ions instantly by accelerating them at varying speeds and, thus, causing friction.
"It's a completely unexpected result," says study lead author Arthur Turrell. "One of the problems with fusion research has been getting the energy from the laser in the right place at the right time. This method puts energy straight into the ions."
Scientists have long turned to high-powered lasers to heat materials in an effort to mimic the fusion happening in the sun and harness that process to create energy. However, the new technique could offer the fastest heating rates ever recorded, moving researchers one step closer to achieving fusion energy.
There's no guarantee, of course, since such a laser has to be built first. Yet the possibility of its bringing fusion energy one step closer is an attractive one, some experts say.
"If, and this is a big if, the mechanism can be applied to solid targets as employed in inertial fusion experiments, it may prove very important," says University of Minnesota physicist James Kakalios, who was not involved in the study.
The goal of fusion energy is to simulate the process happening in the sun where hydrogen atoms heated to around 10 million degrees Celsius fuse to form helium, releasing immense amounts of energy as they do so. If that process could be recreated on Earth in a fusion reactor, it could produce self-sustaining and almost limitless energy, scientists say.
The study was published in the journal Nature Communications on Nov. 13.
