National Ignition Facility (NIF) target chamber. A service module carrying technicians inside the NIF target chamber. The NIF, based in California, USA, is the world's largest and highest-energy laser. When completed, it will house 192 lasers for fusion research. The beams will be focused on a target (centre right to centre middle) in a vacuum, producing a total energy of 1.8 megajoules. The NIF will be used to investigate the fusion of hydrogen nuclei and the viability of fusion as an energy source. Nuclear fusion is the joining (fusing) of light elements to form heavier elements, which releases large amounts of energy. It is hoped that fusion will be a clean, renewable energy source for the future. Photographed in 2009.