While the National Ignition Facility in the US has suffered a series of political and fiscal blows that threaten to cut the budget, laser physicists in Europe have put forward plans to build a laser fusion fascility according to PhysicsWeb.
Laser physicists in Europe have put forward plans to build a £500m facility to study a new approach to laser fusion. A panel of scientists from seven European Union countries believes that a “fast ignition” laser facility could make a significant contribution to fusion research, as well as supporting experiments in other areas of physics. The facility could be up and running by the middle of the next decade.
The most advanced approach to fusion involves using magnetic fields to confine the deuterium–tritium plasma. This is the route to be taken by ITER, which will cost $10bn to build and run. The alternative “inertial confinement” technique, which uses lasers or ion beams rather than magnets to confine the plasma, will be investigated by the National Ignition Facility (NIF) in the US and the Laser Mégajoule (LMJ) in France. However, both these billion-dollar lasers will primarily be used for nuclear-weapons research, with only 15% of their time being available for other areas of physics.
Fast ignition, which was first proposed by Max Tabak of the Lawrence Livermore National Laboratory in the US, relies on different lasers for these two stages. Fast ignition was first demonstrated at the Gekko XII laser at Osaka University in Japan in 2001, working with a team of UK scientists. Kodama and colleagues are now upgrading their laser system in order to approach “breakeven” - the point at which the energy output is equal to the energy needed to sustain the reaction. The European proposal would be designed to achieve high energy gains, providing the critical intermediate step between ignition and a demonstration reactor. It would consist of a long-pulse laser with an energy of 200 kJ to compress the fuel and a short-pulse laser with an energy of 70 kJ to heat it. These power levels are much less than the NIF, whose intended operating level is 1.8 MJ.
