Yangtze River Delta G60 Laser Alliance Introduction
It is reported that Washington - The U.S. Department of Energy (DOE) and the National Nuclear Safety Administration (NNSA) under the Department of Energy announced that Lawrence Livermore National Laboratory (LLNL) has achieved fusion ignition achievements, a major scientific breakthrough in decades that will pave the way for national defense progress and the future of clean energy. On December 5, a team at LLNL National Ignition Device (NIF) conducted the first controlled fusion experiment in history to record this milestone, also known as the scientific energy break-even, meaning it produces more energy from fusion than the laser energy used to drive it. This unprecedented feat will provide unprecedented capabilities to support NNSA's inventory management program and will provide valuable insights into the prospects of clean fusion energy.
researchers generated for the first time the energy generated from nuclear fusion exceeds the energy used to drive fusion, and are expected to make further discoveries in clean energy and nuclear weapons management.
U.S. Department of Energy U.S. Department of Energy (DOE)
National Nuclear Security AdministrationU.S. National Nuclear Safety Administration (NNSA)
Lawrence Livermore National Laboratory Lawrence Livermore National Laboratory (LLNL)
National Ignition FacilityU.S. National Ignition Device (NIF)
U.S. Secretary of Energy Jennifer M. "This is a milestone achievement for researchers and staff at the National Ignition Device, who have been working to witness fusion ignition becoming a reality, and this milestone achievement will undoubtedly inspire more discoveries," Granholm said. "The Biden-Harris administration is committed to supporting world-class scientists, such as the team at NIF, whose work will help us solve the most complex and pressing problems of humanity, such as providing clean energy to combat climate change and maintaining nuclear deterrence without nuclear testing."
Illustration: LLNL National Ignition Device Laboratory, On December 5, 2022, 192 beams of laser beam delivered more than 2 million joules of UV energy to a tiny fuel ball to generate fusion ignition.
"We have had a theoretical understanding of nuclear fusion for more than a century, but the process from understanding to practice is long and arduous. Dr. Alati Prabakar, the president's chief science and technology adviser and director of the White House Office of Science and Technology Policy, said: "Today's milestone shows that we can do it as long as we persevere." "
U.S. Senator Alex Padilla (CA) said: "This major scientific breakthrough is a milestone for the future of clean energy ." "While there is more work to be done in leveraging the potential of fusion energy, I am proud that California scientists continue to be at the forefront of developing clean energy technologies. I congratulate the scientists at Lawrence Livermore National Laboratory for their contribution to the future of clean energy and I am committed to ensuring they have all the tools and funds needed to continue this important work. "
" This is a big deal. We can celebrate another performance record for the National Ignition. This latest achievement is particularly striking, as NIF uses a more asymmetric target than in the August 2021 experiment,” said U.S. Rep. Zoe Lovegren (CA-19). “This significant advance demonstrates the future possibilities for commercialization of fusion energy. Congress and the government need to fully fund and properly implement the fusion research provisions in the recent CHIPS and Science Act. During World War II , we carefully planned the Manhattan Plan to achieve timely results. The world today faces greater challenges than in the past. We must redouble our efforts, accelerate research, and explore new ways of clean, unlimited energy brought by nuclear fusion. ”
Illustration: In LLNL's national ignition device, used to achieve ignition of the cryogenic target cavity. The recessed surface scatters stray light to prevent damage to the laser. Connect a cryogenic cooler (most right) and wires are connected to the heater and the sensor.
What is nuclear fusion?
fusion describes what happens when the nucleus of light atoms (such as hydrogen atom ) overcomes the repulsive electrostatic force that makes them separate. When the nucleus is close enough, the force that binds the protons and neutrons together, i.e., the strong force, takes over and pulls the nucleus closer so that they "fusion" into a new, heavier helium nucleus with two neutrons and two protons.
helium nucleus is also called alpha particle . Its mass is slightly less than the sum of the masses of the two hydrogen nuclei. According to Einstein 's famous formula E=mc2, the poor mass is released in the form of energy. Energy is released in the form of alpha particles, high-energy neutrons and other forms of energy such as electromagnetic radiation .
nuclear fusion is different from nuclear fission , which is the nucleus of heavy elements such as uranium, forming two lighter elements - this process is applied to today's nuclear power plant . In these two types of nuclear reactions , the element itself changes and becomes a new element—in this process, a small amount of mass is converted into a large amount of energy.
Illustration: In fusion reaction , the nuclei of two isotopes of hydrogen, deuterium (containing one neutron and one proton) and tritium (two neutrons and one proton) are forced to gather together under extreme temperature and pressure to fusion to form helium nuclei. In this process, part of the mass of hydrogen is released in the form of energy.
What is ignition?
When the heating power of α particles produced by the fusion reaction of the central hot spot of the target capsule overcomes the cooling effects of x-ray loss, electron conduction and implosion expansion, fusion ignition occurs, thereby causing explosive amplification of the self-heating feedback loop and energy output in the fusion fuel. The goal of NIF is to generate the same or more energy as the laser energy transmitted to the target through nuclear fusion. This will be achieved by creating a "combustion plasma" in which plasma combustion waves of the fusion reaction propagate into the cold fuel around the hot spot. In this process known as alpha heating, alpha particles diffuse throughout the cold fuel, storing their energy, stimulating additional fusion reactions, and greatly increasing yields.
If enough alpha particles are "stopped" or absorbed in the high-density fuel layer, the high-density fuel temperature will be high enough to trigger a self-sustaining thermonuclear reaction, resulting in ignition. For science, achieving ignition will be an unprecedented, game-changing breakthrough and may help lay the foundation for the world to develop a new, infinite clean energy.
Illustration: A pseudo-color illustration of a NIF cavity shaped like rugby and holds an aluminum fuel capsule, which is one of several new target designs being explored on the NIF system. The laser beam enters the cavity through the laser inlet hole, hitting the inside of the cavity to generate x rays . The laser beam is arranged in two cones—an inner cone pointing toward the waist of the cavity and an outer cone pointing toward both ends. Ignition is achieved when a self-sustaining fusion reaction produces more energy than the laser energy delivered to the target.
LLNL experiment exceeded the fusion threshold , transmitting 2.05 megajoules (MJ) of energy to the target, generating 3.15 megajoules of fusion energy output, proving for the first time the most basic scientific basis of inertial fusion energy (IFE). To achieve the IFE required for simple and affordable electricity for homes and businesses, many advanced scientific and technological developments are still needed. The Department of Energy is currently restarting a broad-based, coordinated IFE project in the United States. Coupled with private sector investment, the commercialization process of nuclear fusion will have great momentum.
Nuclear fusion is the process in which two light nuclei combine to form a heavy nucleus and release a large amount of energy. In the 1960s, a group of pioneer scientists at LLNL hypothesized that lasers could be used to induce fusion in laboratory settings.Leaded by physicist John Nuckolls, who later served as LLNL director from 1988 to 1994, this revolutionary idea became inertial constrained nuclear fusion, opening up more than 60 years of research and development in laser, optics, diagnostics, target manufacturing, computer modeling and simulation, and experimental design.
To achieve this concept, LLNL has built a series of increasingly powerful laser systems, thus creating the world's largest and most energy-efficient laser system NIF. Located in LLNL in Livermore, California, NIF is as big as a stadium, it uses powerful laser beams to create temperature and pressure, just like the core of stars and giant planets, and the inside of the explosive nuclear weapons.
Illustration: In order to generate fusion ignition, the laser energy of the national ignition device is converted into x-rays in the cavity, and then the fuel capsule is compressed until it implodes, producing high-temperature and high-pressure plasma.
Illustration: This graph shows a typical indirect driver target configuration. In the middle pattern, the laser beam (blue) enters the cavity through the laser inlet holes at different angles. The pie chart in the upper left corner shows the radial distribution and size of the material in the diamond (high density carbon or HDC) ablator implosion. In the lower left, the time laser power pulse shape (blue) and the associated cavity radiation temperature (green) are shown. On the right, at the center of the cavity, the vesicles are bathed in x-rays, which ablated the outer surface of the vesicles. The generated pressure causes the capsule to implode, compress and heat the fusion fuel.
Creates Energy Record
Illustration: After achieving production of more than 1.3 megajoules (MJ), NIF researchers increased 25 times more than NIF's record production in 2018
Since the first NIF laser launch, scientists have created records of neutron yields and energy generated. Since the beginning of the NIF experiment, neutron production has increased exponentially; more energy is coupled to by to the target capsule; the implosion speed increases; and the pressure at the implosion center is many times higher. The result was a steady increase in energy output and peaked on August 8, 2021, when the NIF experiment produced more than 1.3 megajoules (MJ), 25 times the record yield set in 2018.
NIF also made history in May 2018, when it fired a record 2.15 MJ of UV energy into the target chamber, up 15% from the NIF's 1.8 MJ design specification and over 10% higher than the NIF's previous 1.9 MJ energy record set in March 2012.
Moreover, in a laboratory environment, recent NIF experiments achieved α heating for the first time—when the α particles stimulate additional fusion reactions in cold fuels, the energy generated by exceeds the kinetic energy delivered by the implosion. When the energy deposition of alpha particles generated by fusion contributes more than 50% to the heating of fuel, the burned plasma is achieved, and recent experiments have exceeded this threshold. If better control can be obtained, this process will eventually lead to nuclear fusion ignition as other problems are solved.
researchers are now ready to further improve the performance of NIF by coupling more laser energy into the capsule while maintaining symmetric control. We are also looking for strategies such as novel cavity designs; large capsules; magnetization targets; new methods for capsule processing, installation and filling; and increased laser energy.
Our progress is attributed to decades of outstanding work by previous generations of LLNL scientists and engineers who have advanced the fields of high energy density and ICF science to this day. A new generation of LLNL researchers (as shown in the figure below).
New understanding
Although implementing ignition on NIF has been proven, we have a new understanding of the process in every experiment. Important lessons learned from the limitations of simulations and use this knowledge to solve problems and continuously improve implosion performance.
In particular, high resolution 3D modeling and simulation helps to better understand the source of interference, including "engineering features" of interference implosion performance, such as films of target capsules suspended in the cavity and filler tubes for injecting fuel into the capsules.Other factors that inhibit energy production are the instability of laser plasma and fluid dynamics, the asymmetry of the x-ray flux of the cavity driving implosion, and the mixing of capsule material with fuel.
Add innovation and enhanced diagnosis, such as multiple line-of-sight neutron detectors, which also lead to improved target performance. New high-performance supercomputers and powerful "deep learning" technologies are able to process, analyze and simulate 3D data generated by these diagnostics on a wide range of disturbance sources (capsule surface defects, engineering features, drive asymmetry), which greatly improves the ability to match simulations with experimental results.
At the same time, each ignition experiment promotes scientific developments that ensure the reliability of national nuclear stocks, as well as the implementation of nuclear fusion as a safe, clean and nearly unlimited energy end use.
LLNL Director Kim "The pursuit of fusion ignition in the lab is one of the most significant scientific challenges humans have ever solved, and achieving this is a successful achievement of science, engineering, and most importantly, human victory."
U.S. Senate Majority Leader Charles Schumer (NY ) said: "This amazing scientific advancement pushes us to a future that no longer relies on fossil fuels, but is driven by new clean fusion energy." "I commend Lawrence Livermore National Laboratory and its partners in our Inertial Constrained Fusion (ICF) program, including the Laser Energy Laboratory of the University of Rochester, New York, for achieving this sudden outbreak Break. To make this future clean energy world a reality, it takes our physicists, innovators and talented from the U.S. Department of Energy funding agencies including the Rochester Laser Laboratory to double down on their cutting-edge work. That’s why I am also proud to announce today that I have helped the ICF program get the highest ever authorization of over $624 million in this year’s National Defense Authorization Act to support this amazing breakthrough. “
” After more than a decade of scientific and technological innovation, I congratulate Lawrence Livermore National Laboratory and the team at the National Ignition Devices for historic achievements,” said U.S. Senator Diane Feinstein (CA). “This is an exciting step in the field of nuclear fusion, and everyone at Lawrence Livermore and NIF should be proud of this milestone achievement.”
“This is a historic innovative achievement built on the contributions of generations of scientists in Livermore. Today, our country stands on their shoulders. There is still a long way to go, but it is a crucial step, and I commend the U.S. Department of Energy and everyone who contributed to this breakthrough that will help create a brighter clean energy future for the United States and humanity,” said U.S. Senator Jack Reed, chairman of the Senate Armed Services Committee.
Article source:
https://www.llnl.gov/news/national-ignition-facility-achieves-fusion-ignition
https://lasers.llnl.gov/science/pursuit-of-ignition
Jiangtze River Delta G60Laser Alliance Chen Changjun reprinted
