Laser Megajoule construction. The Laser Megajoule (LMJ) is an experimental nuclear fusion device being built near Bordeaux, France. Its design uses 240 laser beams and 1.8 megajoules of power to heat a target to the point where fusion and power generation occurs. It uses the inertial confinement fusion (ICF) method. Construction of the LMJ started with the Laser Integration Line (LIL, 8 lasers), completed in 2002 and due to be expanded into the full LMJ by 2012. Here, engineers are constructing the LIL's target chamber. Photographed at the Le Barp facility of the French Atomic Agency (CEA).