The quest for fusion energy has broken a major milestone.
For the first time, a fusion reaction has achieved a record 1.3 megajoule energy output, and for the first time, exceeding energy absorbed by the fuel used to initiate it.
The result is eight times greater than experiments conducted a few months prior, and 25 times greater than experiments conducted in the previous year. It's a huge achievement.
Physicists at the National Ignition Facility will be submitting a paper for peer review.
This result is a historic step forward for fusion research, opening a new regime for exploration and advancement of national security. Kim Budil, director of the Lawrence Livermore National Laboratory, said that it is a testament to the innovation, ingenuity, commitment and grit of this team and the many researchers in this field over the decades who have pursued this goal.
"For me, it shows one of the most important roles of the national labs, our relentless commitment to tackling the biggest and most important scientific grand challenges and finding solutions where others might be dissuaded by the obstacles."
Something like a tiny star is created by inertial confinement fusion. It starts with a capsule of fuel, consisting of deuterium and tritium. A fuel capsule is placed in a hollow gold chamber about the size of a pencil eraser.
192 high-powered laser beams are blasted at the hohlraum, where they are converted into X-rays. The fuel capsule is turned into a tiny blob of plasma by these X-rays when they implode it, heating and compressing it to temperatures in excess of 100 million degrees Celsius (180 million Fahrenheit) and pressures greater than 100 billion Earth atmospheres.
The hydrogen and the deuterium and tritium in the fuel capsule are the same as the heavier elements in the heart of a main-sequence star. The process takes a few billionths of a second. The goal is to get the fusion process to produce enough energy to get the total energy input under control.
The experiment was conducted on August 8th and the input from the lasers was 1.9 megajoules. The team's measurement shows that the fuel capsule absorbed less energy than it generated.
This is the result of a lot of work, including the design of the hohlraum and capsule, improved laser precision, new diagnostic tools, and design changes to increase the speed of the implosion of the capsule.
The director of the Los Alamos National Laboratory said that gaining experimental access to thermonuclear burn in the laboratory is the culmination of decades of scientific and technological work.
Experiments that check theory and simulation in the high energy density regime more rigorously than ever before will be enabled by this.
The team will conduct follow-up experiments to see if they can duplicate the result, and to study the process in greater detail. New avenues for experimental research are opened up by the result.
Physicists hope to increase energy efficiency. A lot of energy is lost when the laser light is converted into X-rays inside the hohlraum. We will take another step closer to fusion energy if we solve this problem.
The researchers are very excited.
"Achieving ignition in a laboratory remains one of the scientific grand challenges of this era and this result is a momentous step forward towards achieving that goal," said physicist Johan Frenje of MIT's Plasma Science and Fusion Center.
It allows the exploration of a fundamentally new regime that is extremely difficult to access, furthering our understanding of the processes of fusion ignition and burn, which is critical for validation and enhancing our simulation tools in support of the stockpile stewardship.
The result is historic as it is the culmination of many decades of hard work, innovation and ingenuity, team work on a large scale, and relentless focus on the ultimate goal.
The team presented their results at the meeting.
