The aftermath
After the first successful demonstration of net energy gain, “the first priority was to repeat it,” Budil said. “But the next five shots were duds. They really did not work.”
It seemed to be mostly a problem with the targets, those tiny fuel pellets that the lasers shoot at. The targets need to be virtually perfect, with no defects. Making one takes around seven months from start to finish.
It wound up taking around six months to repeat the initial success, but over the summer, the lab achieved the highest energy gain to date. The team achieved net energy gain twice more in October.
There’s still a lot to learn about fusion, and researchers are trying to do just that with these repeated attempts. On stage, Budil ticked through some of the questions they still had: Could the scientists make changes to the targets? Alter the laser pulse shape? Turn the energy up?
There’s been steady progress on the science and engineering behind fusion energy for decades, Budil said, but new questions always come up as progress gets made.
I asked her when she thought this energy source might be ready for prime time. “My best guess is that you could have a demo power plant in 20 years,” she told me. Some startups are making bolder claims than that, predicting a decade or less, “but I think the challenges are much more significant than people realized at the beginning. Plasmas are really complicated,” she said.