Magnetized liner inertial fusion (MagLIF) is an ongoing fusion power experiment being carried out on the Z Pulsed Power Facility (Z machine) at Sandia National Laboratories in the US. Is it one example of the broader magneto-inertial fusion approach, which attempts to compress a pre-heated plasma. The goal is to produce fusion conditions without the level of compression needed in the inertial confinement fusion (ICF) approach, where the required densities reach about 100 times that of lead.
The term MagLIF may also be used more broadly to refer to machines that use the same operating principle as the one at the Z machine. This includes the Primary Test Stand (PTS) in Mianyang, China. [1]
MagLIF is a method of generating energy by magnetically compressing a cylinder of fusion fuel (such as deuterium). First, an axial magnetic field of 10–20 tesla is applied to the fuel. Then, a multi-kilojoule laser shines through the fuel, preheating it to a few million degrees Celsius and turning it into a plasma. Finally, a 100 nanosecond pulse of electric current is driven axially through the metal liner surrounding the fuel. The current induces an intense Z-pinch magnetic field that crushes the liner and fuel.
The compression does work to the fuel, heating it to tens of millions of degrees Celsius. Normally the electrons in the plasma would be free to escape, and the ions to a lesser extent, carrying away energy and cooling the plasma. The compression also amplifies the axial magnetic field to thousands of teslas, providing magnetic confinement to the imploded plasma and trapping the fuel and its heat. Ideally, the plasma reaches a high enough temperature and density to undergo fusion burn, releasing energy. [2]
MagLIF has characteristics of both inertial confinement fusion (due to the use of a laser and pulsed compression) and magnetic confinement fusion (due to the use of a powerful magnetic field to inhibit thermal conduction and contain the plasma), making it an example of magneto-inertial fusion.
In results published in 2012, a computer simulation using the LASNEX code showed that a 70 megaampere facility would provide an energy yield of 1000 times the expended energy, and a 60 megaampere facility would produce a yield of 100 times the expended energy.
Sandia National Labs is currently exploring the potential for this method to generate energy by utilizing the Z machine. The Z machine is capable of 27 megaamperes and may be capable of producing slightly more than breakeven energy while helping to validate the computer simulations. [3] The Z-machine conducted MagLIF experiments in November 2013 with a view towards breakeven experiments using D–T fuel in 2018. [4]
Sandia Labs planned to proceed to ignition experiments after establishing the following: [5]
Following these experiments, an integrated test started in November 2013. The test yielded about 1010 high-energy neutrons.
As of November 2013, the facility at Sandia labs had the following capabilities: [4] [6]
In 2014, the test yielded up to 2×1012 D–D neutrons under the following conditions: [7]
Experiments aiming for energy breakeven with D-T fuel were expected to occur in 2018. [8]
To achieve scientific breakeven, the facility is going through a 5-year upgrade to:
In 2019, after encountering significant problems related to mixing of imploding foil with fuel and helical instability of plasma, [9] the tests yielded up to 3.2×1012 neutrons under the following conditions: [10]
In 2020, "the burn-averaged ion temperature doubled to 3.1 keV and the primary deuterium–deuterium neutron yield increased by more than an order of magnitude to 1.1×1013 (2 kilojoule deuterium–tritium equivalent) through a simultaneous increase in the applied magnetic field (from 10.4 to 15.9 teslas), laser preheat energy (from 0.46 to 1.2 kilojoules), and current coupling (from 16 to 20 megaamperes)." [11]
A fusion rocket is a theoretical design for a rocket driven by fusion propulsion that could provide efficient and sustained acceleration in space without the need to carry a large fuel supply. The design requires fusion power technology beyond current capabilities, and much larger and more complex rockets.
Inertial confinement fusion (ICF) is a fusion energy process that initiates nuclear fusion reactions by compressing and heating targets filled with fuel. The targets are small pellets, typically containing deuterium (2H) and tritium (3H).
Fusion power is a proposed form of power generation that would generate electricity by using heat from nuclear fusion reactions. In a fusion process, two lighter atomic nuclei combine to form a heavier nucleus, while releasing energy. Devices designed to harness this energy are known as fusion reactors. Research into fusion reactors began in the 1940s, but as of 2024, no device has reached net power, although net positive reactions have been achieved.
Nuclear pulse propulsion or external pulsed plasma propulsion is a hypothetical method of spacecraft propulsion that uses nuclear explosions for thrust. It originated as Project Orion with support from DARPA, after a suggestion by Stanislaw Ulam in 1947. Newer designs using inertial confinement fusion have been the baseline for most later designs, including Project Daedalus and Project Longshot.
This timeline of nuclear fusion is an incomplete chronological summary of significant events in the study and use of nuclear fusion.
The National Ignition Facility (NIF) is a laser-based inertial confinement fusion (ICF) research device, located at Lawrence Livermore National Laboratory in Livermore, California, United States. NIF's mission is to achieve fusion ignition with high energy gain. It achieved the first instance of scientific breakeven controlled fusion in an experiment on December 5, 2022, with an energy gain factor of 1.5. It supports nuclear weapon maintenance and design by studying the behavior of matter under the conditions found within nuclear explosions.
Inertial electrostatic confinement, or IEC, is a class of fusion power devices that use electric fields to confine the plasma rather than the more common approach using magnetic fields found in magnetic confinement fusion (MCF) designs. Most IEC devices directly accelerate their fuel to fusion conditions, thereby avoiding energy losses seen during the longer heating stages of MCF devices. In theory, this makes them more suitable for using alternative aneutronic fusion fuels, which offer a number of major practical benefits and makes IEC devices one of the more widely studied approaches to fusion.
The Laboratory for Laser Energetics (LLE) is a scientific research facility which is part of the University of Rochester's south campus, located in Brighton, New York. The lab was established in 1970 with operations jointly funded by the United States Department of Energy, the University of Rochester and the New York State government. The Laser Lab was commissioned to investigate high-energy physics involving the interaction of extremely intense laser radiation with matter. Scientific experiments at the facility emphasize inertial confinement, direct drive, laser-induced fusion, fundamental plasma physics and astrophysics using the OMEGA Laser Facility. In June 1995, OMEGA became the world's highest-energy ultraviolet laser. The lab shares its building with the Center for Optoelectronics and Imaging and the Center for Optics Manufacturing. The Robert L. Sproull Center for Ultra High Intensity Laser Research was opened in 2005 and houses the OMEGA EP laser, which was completed in May 2008.
The Z Pulsed Power Facility, informally known as the Z machine or Z, is the largest high frequency electromagnetic wave generator in the world and is designed to test materials in conditions of extreme temperature and pressure. It was originally called the PBFA-II and was created in 1985. Since its refurbishment in October 1996 it has been used primarily as an inertial confinement fusion (ICF) research facility. Operated by Sandia National Laboratories in Albuquerque, New Mexico, it gathers data to aid in computer modeling of nuclear weapons and eventual fusion pulsed power plants.
The Tokamak Fusion Test Reactor (TFTR) was an experimental tokamak built at Princeton Plasma Physics Laboratory (PPPL) circa 1980 and entering service in 1982. TFTR was designed with the explicit goal of reaching scientific breakeven, the point where the heat being released from the fusion reactions in the plasma is equal or greater than the heating being supplied to the plasma by external devices to warm it up.
Aneutronic fusion is any form of fusion power in which very little of the energy released is carried by neutrons. While the lowest-threshold nuclear fusion reactions release up to 80% of their energy in the form of neutrons, aneutronic reactions release energy in the form of charged particles, typically protons or alpha particles. Successful aneutronic fusion would greatly reduce problems associated with neutron radiation such as damaging ionizing radiation, neutron activation, reactor maintenance, and requirements for biological shielding, remote handling and safety.
A fusion energy gain factor, usually expressed with the symbol Q, is the ratio of fusion power produced in a nuclear fusion reactor to the power required to maintain the plasma in steady state. The condition of Q = 1, when the power being released by the fusion reactions is equal to the required heating power, is referred to as breakeven, or in some sources, scientific breakeven.
Magnetic confinement fusion (MCF) is an approach to generate thermonuclear fusion power that uses magnetic fields to confine fusion fuel in the form of a plasma. Magnetic confinement is one of two major branches of controlled fusion research, along with inertial confinement fusion.
Magnetized Target Fusion (MTF) is a fusion power concept that combines features of magnetic confinement fusion (MCF) and inertial confinement fusion (ICF). Like the magnetic approach, the fusion fuel is confined at lower density by magnetic fields while it is heated into a plasma. As with the inertial approach, fusion is initiated by rapidly squeezing the target to greatly increase fuel density and temperature. Although the resulting density is far lower than in ICF, it is thought that the combination of longer confinement times and better heat retention will let MTF operate, yet be easier to build. The term magneto-inertial fusion (MIF) is similar, but encompasses a wider variety of arrangements. The two terms are often applied interchangeably to experiments.
Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the reaction heats the fuel mass more rapidly than it cools. In other words, fusion ignition is the point at which the increasing self-heating of the nuclear fusion removes the need for external heating. This is quantified by the Lawson criterion. Ignition can also be defined by the fusion energy gain factor.
Magneto-inertial fusion (MIF) describes a class of fusion power devices which combine aspects of magnetic confinement fusion and inertial confinement fusion in an attempt to lower the cost of fusion devices. MIF uses magnetic fields to confine an initial warm, low-density plasma, then compresses that plasma to fusion conditions using an impulsive driver or "liner." The concept is also known as magnetized target fusion (MTF) and magnitnoye obzhariye (MAGO) in Russia.
Helion Energy, Inc. is an American fusion research company, located in Everett, Washington. They are developing a magneto-inertial fusion technology to produce helium-3 and fusion power via aneutronic fusion, which could produce low-cost clean electric energy using a fuel that can be derived exclusively from water.
The history of nuclear fusion began early in the 20th century as an inquiry into how stars powered themselves and expanded to incorporate a broad inquiry into the nature of matter and energy, as potential applications expanded to include warfare, energy production and rocket propulsion.
Lattice confinement fusion (LCF) is a type of nuclear fusion in which deuteron-saturated metals are exposed to gamma radiation or ion beams, such as in an IEC fusor, avoiding the confined high-temperature plasmas used in other methods of fusion.