Nuclear fusion research takes a step forward
Europe, Japan and the ITER organisation have achieved a landmark
success in their quest to create a nuclear-fusion-powered reactor.
Fusion for Energy (F4E), the Joint Undertaking that provides Europe's
contribution to ITER, has, with the support of its partners,
successfully tested a prototype superconductor for a major component of
the ITER project.
ITER, the world's largest experimental fusion facility, is based in
the south of France and aims to harness energy produced by nuclear
fusion to provide an abundant source of power that is safe,
environmentally responsible and economically viable.
Nuclear fusion, or the joining of small nuclei to make a larger
nucleus, is an energy-producing process that occurs naturally in stars.
Nuclear fusion creates considerably more energy and less radioactive
material than nuclear fission, and generates millions of times more
energy than the burning of coal. Since the 1950s, researchers have been
trying to control fusion power in a contained space in order to
generate electricity.
In nuclear fusion, ions are mixed with electrons and a plasma is
formed. One of the challenges of controlling nuclear fusion is
confining and igniting this plasma in a self-sustaining way. ITER is an
international experiment using a tokamak, or a machine producing a
'toroidal' magnetic field for confining the plasma.
The components of ITER are manufactured by each of the
participating countries. One major component is a set of 'poloidal
field coils,' which are used to maintain plasma equilibrium. The coils
are made of titanium and niobium, and shape the inside of the reactor.
The coil system comprises a central coil and seven ring coils,
wound from a large 'cable-in-conduit' conductor and covered by a
stainless-steel jacket. Together they should provide magnetic fields
that confine the plasma and control its position, as well as
contributing to the magnetic 'flux change' that ramps up and maintains
the plasma current.
The prototype is 1.5m in diameter and weighs 6 tonnes, and came out
of a collaboration between Russia, Europe and Japan. Russian
researchers made the superconducting strands that went into the coils,
and European researchers put the jacket on and wound the conductor. The
coil was tested at the Japan Atomic Energy Agency site in Naka, Japan
with expert representation from ITER, Europe, Japan, Russia and the
United States.
The recent test of the coil-system prototype was successful in that
the coils reached a stable operation at 52kA in a 6.3-Tesla magnetic
field. This indicates that the design of the prototype is appropriate
to the demands that will be placed on it. The success represents a
major milestone in fusion research, as the project can move on to
procuring the next component: poloidal field conductors.
ITER is one of the world's most expensive scientific projects, and
the EU will contribute almost half of the costs of construction. The
rest will be funded equally by China, India, Japan, the Republic of
Korea, Russia and the United States. The EU's financial contribution
comes almost entirely from the Euratom budget.
The ITER project is scheduled to last for 30 years. One of the
objectives of the project is to conduct its first plasma operation in
2018, and produce a full-scale power plant by 2050. Fusion for Energy,
a 35-year joint undertaking established in April 2007, seeks to
reinforce Europe's position as a world leader in the development of
fusion energy. The technology provides hope that our growing global
energy needs can be met without producing climate-changing greenhouse
gases.
Source: Community R&D Information Service (CORDIS)