The ultimate purpose of NIF is to focus all the energy from an array of powerful laser beams onto a pea-sized target. The lasers don’t fire continuously, but in a brief pulse just 20 billionths of a second long. That’s enough to raise the target to the enormous temperatures and pressures the researchers need.
From the initial creation of the laser pulse to blasting the target only takes a few microseconds, but a lot happens in that time. To start with, a single weak pulse is created in the master oscillator room. This is then split into a total of 192 separate beams inside the two giant laser bays, where the beams are progressively amplified as they pass back and forth through the system. The energy for this comes from super-powerful flashlamps which illuminate a series of glass slabs through which the beams pass, constantly gaining energy as they do so.