Podcast Summary
Lawrence Livermore National Labs' Fusion Project with High-Powered Lasers: Acting director Bruno Van Wangerheem aims to make fusion energy portable using high-powered lasers, despite challenges in obtaining necessary fuel and reaching ignition temperatures.
The National Ignition Facility at Lawrence Livermore National Labs, under the leadership of acting director Bruno Van Wangerheem, is working on fusion technology using high-powered lasers. The fusion process requires extremely high temperatures to ignite, and tritium, a necessary fuel, can be found in various sources including the universe and mines. Despite the challenges, Van Wangerheem aims to make fusion energy portable in the future. Van Wangerheem's background in laser physics and his experience working at various institutions, including the University of Leuven in Belgium and the Max Planck Institute in Germany, have prepared him well for his role in the fusion research. The collaboration between visiting scientists and his team at Livermore led him to the current project, which involves casting shade on the sun's energy production process by attempting to replicate it through fusion.
Igniting a self-sustaining plasma reaction: The National Ignition Facility's experiment successfully ignited a plasma, releasing a large amount of energy in a short time, showing potential for future designs with fewer energy inputs.
The National Ignition Facility's experiment involved igniting a plasma, which is a self-sustaining and heating plasma that generates more fusion reactions and heat production. The ignition process was compared to striking a match, where a small initial energy input leads to a self-sustaining and rapidly increasing reaction, releasing an enormous amount of energy in a very short time. Despite using 300,000,000 joules of energy as a starting point, the experiment was not designed for maximum efficiency but rather for cost-effectiveness. The success of the experiment demonstrates the potential for future designs that could ignite a plasma with fewer inputs of energy.
Lasers compress fuel capsule for fusion reaction: To make fusion energy economically viable, researchers must focus on developing more efficient laser drivers and creating self-sustaining reactions, reducing the energy required to power the lasers.
The process of creating fusion energy through inertial confinement involves using lasers to compress a fuel capsule, resulting in a nuclear reaction that releases energy. However, the energy required to power the lasers is not included in the calculation of the return on investment. To make this process economically viable for a power plant, researchers need to focus on developing more efficient laser drivers and creating self-sustaining fusion reactions. These reactions, unlike nuclear power plants, do not have the risk of a runaway chain reaction or meltdown. The high temperatures required for fusion are necessary to overcome the repulsive forces between atomic nuclei and allow them to combine. The process involves repeatedly compressing and igniting new fuel capsules, making it a continuous process.
Reaching the highest temperatures for nuclear fusion: Scientists aim to increase temperatures to harness the full power of the nuclear force for nuclear fusion, a long-term goal despite the sun's relatively small fusion energy production.
Creating the extreme temperatures required for nuclear fusion to occur is a significant challenge. It involves increasing the velocity of atoms colliding with each other to reach temperatures of around 150,000,000 degrees for deuterium and tritium, and even higher temperatures for other systems. This process has taken decades of research and technological advancements, with scientists and researchers working in labs across the world. Although the sun's core is not hot enough to fuse hydrogen outright, it does so through quantum tunneling. However, researchers aim to increase temperatures to take advantage of the full nuclear force, despite the sun's fusion energy production being relatively small. The sun's size is what primarily contributes to its enormous energy output. In essence, the pursuit of nuclear fusion is about harnessing the full power of the nuclear force by reaching the highest temperatures, which has been a long-term goal for scientists.
Lawrence Livermore National Labs working on laser fusion with neutron energy recovery: Scientists aim to harness neutron energy in laser fusion using molten salt mantle, potentially creating a sustainable energy source
Scientists at Lawrence Livermore National Labs, led by Bruno Van Weltenheim, are working on a fusion reaction using lasers to ignite deuterium and tritium atoms, forming helium, a neutron, and releasing a large amount of energy. The neutron, which carries a significant portion of the reaction's energy, is currently being allowed to scatter and waste away, but researchers are exploring ways to harness this energy using a molten salt mantle around the target chambers, which can absorb the neutrons and heat up, generating energy without the need for traditional fossil fuels. This process, if successful, could lead to a sustainable energy source, potentially replacing the use of oil and other non-renewable resources.
Heavy hydrogen and radioactive tritium in fusion reactions: Heavy hydrogen (deuterium) and radioactive tritium are used in fusion reactions to generate large amounts of energy. Tritium is currently produced as a byproduct in nuclear reactors, but the ideal process is to create it through fusion reactions, making the process self-sustaining. Deuterium and helium 3, a rare isotope, are also used in fusion reactions.
Hydrogen, which is the most abundant element in the universe, can have additional neutrons to become heavier isotopes like deuterium and tritium. Deuterium, with one neutron extra, is called heavy hydrogen and makes up about 0.015% of hydrogen in natural water. Tritium, with two neutrons extra, is a radioactive isotope that is not naturally abundant but can be produced in nuclear reactions. Currently, tritium is produced as a byproduct in nuclear reactors, but the ideal process for inertial fusion energy is to use the neutrons generated in the fusion process to create tritium, making the process self-perpetuating. Additionally, helium 3, a rare isotope of helium with one neutron less than the normal helium, can be found in trace amounts in the solar wind and the moon's surface. The ultimate goal is to use these heavy isotopes to create fusion reactions that can produce large amounts of energy.
Deuterium-Tritium Fusion: The Most Effective Way: The deuterium-tritium fusion reaction is the most effective and efficient way to achieve ignition and operate a nuclear fusion system due to its lower temperature threshold and greater effectiveness. Advancements in laser technology, such as the National Ignition Facility, have significantly enhanced fusion research.
While there are alternative fusion reactions, such as d plus helium 3, the most effective and efficient way to achieve ignition and operate a nuclear fusion system is through the deuterium-tritium (DT) fusion reaction. This is largely due to the lower temperature threshold required to initiate the reaction and its greater effectiveness. Furthermore, the advancements in laser technology, specifically the National Ignition Facility (NIF), have been crucial in enabling and enhancing fusion research. The NIF, which contains 192 individual lasers, each the most powerful laser in the world, has significantly surpassed previous lasers in terms of energy and power output. This departure from traditional lasers has allowed for significant progress in fusion research, with the ignition experiment being successfully conducted in 2009. Despite the advances, it's important to note that the physics behind all lasers, including the small presentation laser, are based on the same principle of light amplification by stimulated emission of radiation.
Lasers for Fusion: From Infrared to Ultraviolet: Lasers, used in fusion for energy absorption, initially operate in the infrared range but are converted to ultraviolet for deeper penetration and better fusion outcomes.
Lasers are highly concentrated beams of light produced through the stimulated emission of radiation. They are designed to emit a single wavelength of light and offer high coherence, meaning a narrow spectrum and spatial distribution of energy. Traditional lasers often operate in the infrared region, but for fusion applications, shorter wavelengths like green and ultraviolet are preferred. This is because ultraviolet light penetrates deeper into the plasma, leading to more efficient energy absorption and better fusion reaction outcomes. The National Ignition Facility at Lawrence Livermore National Lab primarily uses neodymium in glass media for their lasers due to their high energy handling and efficiency, which usually falls in the infrared range. However, to improve fusion efficiency, they convert the infrared lasers to ultraviolet, allowing deeper penetration and more energy absorption in the plasma. Overall, the field of lasers and their applications, particularly in fusion, showcases a remarkable dedication to efficiency and innovation.
The pursuit of more powerful lasers for nuclear fusion research: Advanced laser technology is crucial for creating the perfect conditions for nuclear fusion, requiring high energy, power, precision, and stability.
The development of powerful lasers for nuclear fusion research is an iterative process. Each new design leads to the discovery of new challenges, requiring more powerful and precise lasers to achieve the necessary conditions for ignition. The lasers must provide high energy and power, but also extreme precision and stability. The end goal is to create a perfect implosion of a fuel capsule, resulting in a plasma with the right temperature and density for sustained fusion reactions. Plasma, a collection of energized atoms, plays a crucial role in nuclear fusion. While lasers are used for diagnostic purposes in some fusion experiments, such as the tokamak, which uses magnetic fields to contain the plasma, other approaches like inertial confinement fusion rely on powerful lasers to create the necessary conditions for ignition. Plasmas, which can respond to magnetic fields, come in various forms, including the plasma used in older television technologies like neon and fluorescent tubes, which are easily ionized and don't require high temperatures to form. However, the plasma used in nuclear fusion research is at much higher temperatures and densities, making the process much more complex and requiring advanced laser technology.
Advancements in laser technology for nuclear fusion lead to real-world applications: Laser tech for nuclear fusion hardens turbine blades and promises inertial fusion power plants, but still in engineering phase
The research and development in laser technology for nuclear fusion, specifically inertial fusion, have led to significant advancements and spin-offs with real-world applications. For instance, the technology has been used to harden turbine blades for jet engines, improving their durability and safety. Furthermore, the potential for inertial fusion energy-based power plants is promising, with the goal of creating a working model within the next few decades. However, it's important to note that the technology is still in its engineering phase and requires significant development to become scalable and efficient enough for widespread use.
Advancements in laser technology for energy production: Lawrence Livermore National Laboratory is exploring laser technology for higher fusion yields, potentially reaching 500 megajoules or even gigajoules, and collaborating with private industry on inertial fusion energy.
While it may be challenging to create compact laser systems for weapons or energy production at the moment, history shows that technology once considered impossible can become a reality. Bruno Roessler discussed the advancements in computer technology as an example, and the potential for scaling up laser technology is being explored at Lawrence Livermore National Laboratory for fusion applications. The lab's mission is focused on nuclear energy and stockpile stewardship, and the next goal is to achieve even higher yields, potentially around 500 megajoules or even gigajoules. The lab is also collaborating with private industry on inertial fusion energy. So, while laser guns or time travel may not be imminent, the pursuit of advanced energy technologies and their potential applications continues to be a significant focus.
The Importance of Expertise and Leadership: Expertise and leadership are crucial for driving progress and innovation. Having knowledgeable individuals in charge inspires and guides teams towards remarkable results.
Learning from this episode of StarTalk is the importance of expertise and leadership, as exemplified by our guest, Bruno Van Walter Geum. Walter Geum is the Bossman at the National Ignition Facility at Lawrence Livermore National Labs in Livermore, California. He leads a team of scientists and engineers in groundbreaking research, including nuclear fusion. The conversation highlighted the significance of having knowledgeable individuals in charge, who can inspire and guide their teams towards achieving remarkable results. Walter Geum's dedication and expertise in his field have led to significant advancements in scientific research. Moreover, the conversation emphasized the importance of continuing to learn and look up to those who inspire us. By staying curious and open-minded, we can broaden our horizons and gain a deeper understanding of the world around us. In essence, this episode underscores the importance of expertise, leadership, and a curious mindset in driving progress and innovation. As Neil DeGrasse Tyson always says, "Keep looking up!"