Laser fusion would require a separate book to describe. Here it is treated briefly as an alternative to tokamak fusion. The idea is to put a deuterium-tritium mixture

into a capsule about 2 mm (~1/16 in.) in diameter and hit it from all sides with a huge amount of laser power for several billionths of a second. The power from NIF in one short pulse is 500 times the total electric power capacity of the USA. This is what is supposed to happen.

In Fig. 10.39a, the laser or ion beam energy impinges on a capsule uniformly from all sides. The capsule contains fuel in the form of solid DT, covered by a sacrificial layer called an ablator. The ablator is immediately ionized into a dense plasma, which expands violently away from center. The capsule is compressed as if jet engines had taken off on all sides. Figure 10.39b shows the expanding plasma compressing the capsule. With sufficient laser power, the DT fuel is compressed to a density of 1,000 g/cm3, approximately 100 times the density of lead; and the temperature reaches 10 keV. The breakeven condition equivalent to the Lawson criterion (Chap. 5) is pR > 1 g/cm2, where p is the density in g/cm3 and R is the final radius in centimeters. Fusion occurs, and there is a miniature explosion releasing the helium and neutron products. The energy of an NIF pulse is about 1.8 MJ, and the energy generated could be as much as 100 MJ, equivalent to 24 kg of TNT. To produce 1,000 MW of thermal power would require ten explosions per second. Glass lasers, however, can pulse only once every few hours.