Laser Mégajoule

Laser Mégajoule (LMJ) is a large laser-based inertial confinement fusion (ICF) research device near Bordeaux, France, built by the French nuclear science directorate, Commissariat à l'Énergie Atomique (CEA).

Laser Mégajoule's primary task will be refining fusion calculations for France's own nuclear weapons.

[4] When the amplification is complete, the beams travel towards the "line end", closest to the target chamber in the center of the building.

Each beam is reflected off a series of six mirrors to rearrange them from their parallel orientation in the beamlines to be arranged around the target chamber.

[4] The experimental chamber consists of a 10-metre (33 ft) diameter sphere of 10-centimetre (3.9 in) thick aluminum, weighing around 140 metric tons.

[5] Like NIF, LMJ intends to use the "indirect drive" approach, where the laser light is used to heat a high-Z cylinder made of some heavy metal (often gold) known as a "hohlraum".

When the shock wave converges from all directions and meets in the middle, the density and temperature briefly reach the Lawson criterion and start fusion reactions.