Feature Report: Nuclear Fusion : A Technological Challenge

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Going in depth


Taming Nuclear Fusion, a Long Way to Go

Research on nuclear fusion has been a focus for scientists worldwide for more than 50 years, with men and women from all over the world working together on the ITER project. But it will be decades before this inexhaustible source of energy can be harnessed to produce electricity on a commercial scale. Although progress has been made in different areas, there is no guarantee that these efforts will ultimately be successful.

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Construction began on the ITER site in Saint-Paul-lez-Durance, France in 2010. © BORIS HORVAT / AFP

If nuclear fusionReaction in which two atoms join to form one heavier atom, releasing energy... 1 is one day harnessed, it will spark a real revolution. PowerIn physics, power is the amount of energy supplied by a system per unit time. In simpler terms, power can be viewed as energy output... will be generated from a virtually inexhaustible source of energy that produces little radioactive waste and no greenhouse gases. But there is still a long way to go.

50 Years of Research Already…

Since the 1960s, researchers have managed to produce nuclear fusion reactions in donut-shaped magnetic confinement devices. These tokamaks  — an acronym taken from the Russian Toroidalnaya Kamera Magnitnymi Katushkami, or toroidal chamber with magnetic coils — are found in Japan, the United Kingdom and France. In 1997, the Culham JET Tokamak in the United Kingdom produced a record 16 megawatts (MW) for one second. However, it took 23 MW of energy from an external source to do so.

2050 The deadline set by ITER for producing energy using a thermonuclear reactor

The Cadarache Tore Supra Tokamak in France set another record, maintaining plasma at over three times the Sun's temperature (about one million degrees in the corona) for over six minutes. The JT-60 Tokamak in Japan achieved record temperatures of some 200 million degrees.

The ITER Project

A number of countries are cooperating in nuclear fusion research through the International Thermonuclear Experimental Reactor (ITER)An international project to design and build the first experimental fusion reactor that produces more energy than it uses... 2 project. China, the European Union, India, Japan, South Korea, Russia and the United States are working together to build an experimental fusion reactor that combines all the knowledge and expertise developed and acquired over the last 50 years.

ITER’s goal is to “demonstrate the technological and scientific feasibility of fusion energy by 2050.3 Construction of ITER in Cadarache,4 southern France, has already begun. The initial experiments are expected to begin in 2018 and run for around 20 years.

ITER’s backers are already looking at what comes next — a plant that will demonstrate the feasibility of large-scale nuclear fusion. They have even given it a name, the Demonstration Power Plant (DEMO). However, the prototype will not be coming on stream any time soon. Operated by the European Union and Japan, it will be launched after the ITER operating phase, around 2040.

A Host of Challenges

For the international scientific community, the challenges involved in developing a thermonuclear reactor include:

  • Obtaining the high temperatures required for nuclear fusion.
  • Achieving self-sustaining fusion so that the reactor can operate non-stop.
  • Generating more energy from fusion than is required to produce fusion.

Researchers at Cadarache maintained plasma at a million degrees for more than six minutes.


To achieve this, the ITER project will have to:



(1) ITER

(2) ITER

(3) (4) and (5) What purpose does ITER serve?