FUSION - New Project just heard about today

[zorgon]

FUSION - New Project just heard about today

This one needs looking into..

ITER  A new Fusion Giant Tokamak. Looks like they are going for Deutronium/Tritium fusion confinment (leading up to HE3 fusion...

The Science

Scientists working at the recently-built facility at the ASIPP, Institute of Plasma Physics, in Hefei, China, for the jacketing of superconducting cable for ITER.


Scientists working at the recently-built facility at the ASIPP, Institute of Plasma Physics, in Hefei, China, for the jacketing of superconducting cable for ITER. Photo: Peter Ginter

Over the past 50 years, immense progress has been made in the fields of plasma science and fusion technology. Still, harnessing fusion power and delivering it for industrial applications remains one of the greatest challenges of our time.

One of the tasks awaiting ITER is to explore fully the properties of super hot plasmas—the environment in which the fusion reaction will occur—and their behaviour during the long pulses of fusion power the ITER machine will enable.

The challenge will be very great. ITER's plasma pulses will be of a much longer duration than those achieved in other devices, creating intense material stress. ITER will be used to test and validate advanced materials and key technologies for the industrial fusion power plants of the future.

All through fusion history, challenges which appeared insurmountable have been overcome. Developments in fusion science have been constant and impressive. Gains in temperature and confinement time—two of the main parameters for fusion—have been recorded steadily.

ITER, which incorporates the experience of all previous fusion machines, will take fusion to the point where industrial applications can be considered for providing mankind with a cleaner, safer, and unlimited source of energy.

Fuelling the Fusion Reaction

Heavy, heavier, heaviest... A molecule of ordinary water is made of two atoms of hydrogen and one of oxygen. In the second vial, hydrogen is replaced by one of its two isotopes, deuterium. Tritium atoms replace all hydrogen atoms in the third and heaviest vial.


Heavy, heavier, heaviest... A molecule of ordinary water is made of two atoms of hydrogen and one of oxygen. In the second vial, hydrogen is replaced by one of its two isotopes, deuterium. Tritium atoms replace all hydrogen atoms in the third and heaviest vial. With this picture, Life Magazine explained the notion of "heavy isotope" to its readers in May 1950.

Although different isotopes of light elements can be paired to achieve fusion, the deuterium-tritium (D-T) reaction has been identified as the most efficient for fusion devices. ITER and the future demonstration power plant DEMO will use this combination of elements to fuel the fusion reaction.

Deuterium can be distilled from all forms of water. It is a widely available, harmless, and virtually inexhaustible resource. In every litre of seawater, for example, there are 33 milligrams of deuterium. Deuterium is routinely produced for scientific and industrial applications.

Tritium is a fast-decaying radioelement of hydrogen which occurs only in trace quantities in nature. It can be produced during the fusion reaction through contact with lithium, however: tritium is produced, or "bred," when neutrons escaping the plasma interact with lithium contained in the blanket wall of the tokamak.

Global inventory for tritium is presently around twenty kilos, which ITER will draw upon during its operational phase. The concept of "breeding" tritium within the fusion reaction is an important one for the future needs of a large-scale fusion power plant.

Plasma Confinement

Magnetically confined plasma in the Korean superconducting tokamak, KSTAR. The extreme temperature plasma radiates in a spectrum that our eyes can not see. What is visible in this image are the colder regions on the outer edge of the plasma.


Magnetically confined plasma in the Korean superconducting tokamak, KSTAR. The extreme temperature plasma radiates in a spectrum that our eyes can not see. What is visible in this image are the colder regions on the outer edge of the plasma. Photo: KSTAR.

Physicists have been exploring the properties of plasmas within tokamak devices since the 1960s. The doughnut-shaped torus of the tokamak represented a major break-through in plasma science at the time: here temperature levels and plasma confinement times reached levels that had never been attained before.

The ITER Tokamak chamber will be twice as large as any previous tokamak, with a plasma volume of 830 cubic metres. Left to itself, the plasma would occupy all of the space in the chamber, however no material could withstand contact with the extreme-temperature plasma. Scientists are able to contain or "confine" the plasma away from the walls by exploiting its properties.

Plasmas consist of charged particles—positive nuclei and negative electrons—that can be shaped and confined by magnetic forces. Like iron filings in the presence of a magnet, particles in the plasma will follow magnetic field lines. The magnetic field acts as a recipient that is not affected by heat like an ordinary solid container.

In ITER, different types of magnetic fields will work in subtle combination to shape the plasma into the form of a ring, or torus, and isolate the very hot plasma from the relatively cold vessel walls in order to retain the energy for as long as possible. The vacuum vessel is the first safety confinement barrier and will not be in contact with the plasma.

https://www.iter.org/sci#whatisfusion

[micjer]

"We are unveiling the first world-class controlled fusion device to have been designed, built and operated by a private venture. The ST40 is a machine that will show fusion temperatures — 100 million degrees — are possible in compact, cost effective reactors. This will allow fusion power to be achieved in years, not decades."

No material known to science that can withstand such enormous temperatures, so researchers use powerful magnetic fields to contain the plasma. Next up for Tokamak Energy is installing a full set of magnetic coils inside ST40. Later this year, it will try to get temperatures inside the ST40 up to 15 million degrees Celsius. From there, it hopes to achieve the 100 million degree threshold sometime in 2018. If it can, the promise of clean electrical power from fission could be attained as early as 2030.

Moving from the laboratory to commercial application is always fraught with setbacks, delays, and failures. The promise of virtually unlimited clean energy is one that has fired the imaginations of physicists for generations. It might be a little early to invest your life savings in Tokamak Energy, but you might want to keep an eye on the company. Nuclear fusion could be the final stake through the heart of the fossil fuel industry.