Fusion Facts

Fusion science is a subfield of plasma science that deals primarily with studying the fundamental processes taking place in plasmas where the temperature and density approach the conditions needed to allow the nuclei of two low-mass elements, like hydrogen isotopes, to join together, or fuse. When these nuclei fuse, a large amount of energy is released. Fusion science research is organized around the two leading methods of confining the fusion plasma-magnetic, where strong magnetic fields constrain the charged plasma particles, and inertial, where laser or particle beams compress and heat the plasma in very short pulses.

Source: energy.gov

Scientists have sought to make fusion work on earth for over 50 years. If we are successful, we will have an energy source that is inexhaustible. One out of every 6500 atoms of hydrogen in ordinary water is deuterium, giving a gallon of water the energy content of 300 gallons of gasoline…

Continue reading at www.science.doe.gov

Hydrogen gas is typically heated to very high temperatures (100 million degrees or more) to give the atoms sufficient energy to fuse. In the process the gas becomes ionized, forming a plasma. If this plasma is held together (i.e. confined) long enough, then the sheer number of fusion reactions may produce more energy than what’s required to heat the gas, generating excess energy that can be used for other applications. The sun and stars do this with gravity. More practical approaches on earth are magnetic confinement, where a strong magnetic field holds the ionized atoms together while they are heated by microwaves or other energy sources, and inertial confinement, where a tiny pellet of frozen hydrogen is compressed and heated by intense radiation, such as a laser beam, so quickly that fusion occurs before the atoms can fly apart.

Source: www.science.doe.gov

There are two major approaches to fusion. These are magnetic fusion energy (MFE), where the hot plasma is held within a “magnetic bottle” at high enough temperature and pressure for a long enough time for fusion to occur, and inertial fusion energy (IFE) where a small amount of fusion fuel is heated and compressed by intense energy pulses (from lasers, ion accelerators or pulse power machines), so that fusion conditions of high temperature and pressure are achieved for a brief instant while inertia holds the fuel together.

Source: fed.ans.org

ITER is a joint international research and development project that aims to demonstrate the scientific and technical feasibility of fusion power.

• The partners in the ITER project are the European Union (represented by EURATOM), Japan, the People’s Republic of China, India, the Republic of Korea, the Russian Federation and the USA.
• A tokamak is a machine producing a toroidal (doughnut-shaped) magnetic field for confining a plasma. It is one of several types of magnetic confinement devices and the leading candidate for producing fusion energy. ITER is a tokamak.
• ITER is a tokamak, in which strong magnetic fields confine a torus-shaped fusion plasma. The device’s main aim is to demonstrate prolonged fusion power production in deuterium-tritium plasma.
• The ITER device is based on the tokamak concept, in which a hot gas is confined in a torus-shaped vessel using a magnetic field. The gas is heated to over 100 million degrees, and will produce 500 MW of fusion power.
• ITER will produce about 500 MW (output power) of fusion power in nominal operation, for pulses of 400 seconds and longer. Typical plasma heating levels during the pulse are expected to be about 50 MW (input heating power), so power amplification (Q) is 10.
• If all goes well with the operation of ITER and the construction of the first electricity-generating plant that follows it, the first reliable commercially available electrical power from fusion should be available around 2045.
• ITER is more than just fusion energy sciences; it may well be the path forward for all of large-scale truly international science collaboration.

Source: our-energy.com

ITER (also Latin for “the way”) is a critical step between today’s studies of plasma physics and tomorrow’s fusion power plants producing electricity and hydrogen. An unprecedented international collaboration of scientists and engineers led to the design of this advanced physics experiment. Project partners are China, the European Union, India, Japan, Russia, South Korea, and the United States. ITER is technically ready to start construction, with experimental operations planned to begin in approximately 10 years. The site selected for the project is Cadarache, in southeastern France. ITER is expected to operate for 20 years, and to demonstrate production of at least 10 times the power used to heat the fusion fuel.

For more information, visit www.science.doe.gov

The DIII-D tokamak operated by General Atomics in San Diego, CA is the largest magnetic fusion facility in the United States. DIII-D provides for considerable experimental flexibility and has extensive diagnostic instrumentation to measure the properties of high temperature plasmas. It also has unique capabilities to shape the plasma and provide feedback control of error fields that, in turn, affect particle transport and the stability of the plasma. In addition, DIII-D has been a major contributor to the world fusion program over the past decade in the areas of plasma turbulence, energy transport, boundary layer physics, and electron-cyclotron plasma heating and current drive.

For more information, visit www.science.doe.gov

NSTX (the National Spherical Torus Experiment) is an innovative magnetic fusion device that was constructed by the Princeton Plasma Physics Laboratory (PPPL) in collaboration with the Oak Ridge National Laboratory, Columbia University, and the University of Washington at Seattle. It produces a plasma that is shaped like a sphere with a hole through its center, different from the “donut” shaped plasmas of conventional tokamaks. This configuration may have several advantages, a major one being the ability to confine a higher plasma pressure for a given magnetic field strength, which could enable the development of smaller, more economical fusion reactors.

For more information, visit www.science.doe.gov

Alcator C-Mod at the Massachusetts Institute of Technology is the only tokamak in the world operating at and above the ITER design magnetic field and plasma densities, and it produces the highest pressure tokamak plasma in the world, approaching pressures expected in ITER. It is also unique in the use of all-metal walls to accommodate high power densities. Because of these characteristics, C-Mod is particularly well suited to examine plasma regimes that are highly relevant to ITER. The facility has made significant contributions to the world fusion program in the areas of plasma heating and current drive, stability, and confinement in high field tokamaks.

For more information, visit www.science.doe.gov

Visit: www.science.doe.gov