The shot from the huge 192 lasers generated 2.05 megajoules of energy that resulted in 3.15 megajoules of fusion energy output. It proved, for the first time, that fusion is possible, capping a nearly six-decade effort and opening the door to an even more demanding season. Fusion is the energy that powers the sun and other stars. One of the lab leaders noted that during the shot conditions for a very, very brief time were more than 2 times higher than the center of the sun.
The successful shot took place at 1 a.m. on Dec. 5 and exceeded the output on a shot last August that showed positive results. The challenge for the NIF team is that they had not been able to replicate the 2021 results in four additional tests until the Dec. 5 success. The Energy Dept. pulled out all of its big wigs to tout the remarkable achievement that conveniently fits into their clean energy drive.
The lab’s core competency has been hinged to lasers for decades. The concept for NIF grew out of the need to better understand nuclear weapons once the test ban took effect 30 years ago. As lab Director Kim Budil said, borrowing a line from a former laser leader, that LLNL stands for Lasers, Lasers, Nothing but Lasers. A friend, who is a retired lab employee in computations, remarked that when he came on board in the 1970s magnetic fusion was a key program at the lab—I remember that as well, but those programs were mothballed and the focus became lasers and NIF.
NIF and achieving fusion demonstrates just how persistently and effectively the lab does big science. Just to construct the bay of lasers that are housed in a specially constructed building the size of three football fields, the NIF team had to invent new technology as they went along. That included finding a way to grow crystals for the optics much faster. The NIF portion of the lab’s website touts “The Seven Wonders of NIF” for those new achievements. It cost $3.5 billion to build and has an annual budget of $349 million.
As director Budil observed, this is a milestone, but there’s lots and lots to do before there’s a fusion power plant providing nuclear energy without nuclear waste (the downside of fission reactors) and limitless fuel.
The engineering challenges have been daunting to date. The shot lasts a fraction of a second with tolerances measured in the trillions as the lasers bombard a BB-sized target. The challenge now becomes scale—moving from one shot to many shots per minute to produce energy. Budil declined to say whether that plant is another six decades away—she indicated she hoped the time would be shorter. President Biden has challenged researchers to provide one in 10 years—likely a pipe dream given the amount of technical hurdles awaiting either laser or magnetic fusion.
One encouraging fact is that fusion was achieved with lasers using technology developed years ago and they have gotten better and better. For the record, it took from May 1997 to May 2009, 12 years, to build NIF.
Listening to the lab team of seven who presented on a panel in Washington D.C. after the formal announcement, you could not help but be impressed. Congrats to all involved for many, many years. Enjoy the bubbly and then get back to it.