Inertial Confinement Fusion
Another possibility in achieving a fusion reactor, and the method our Z-machine utilizes, is inertial confinement. This idea, dating back to the early 1970's, uses radiation to compress a pellet of hydrogen fuel. If compressed quickly and hard enough, the temperature and density rise, approaching the critical temperature for fusion to occur. The inertia of the imploding pellet is then strong enough to keep it confined momentarily[2]. This is exactly how fusion is initiated in the H-bomb. However, to control this reaction and prevent creating an H-bomb, the reaction must remain confined.
Researchers first came to the conclusion that to achieve inertial confinement in the laboratory, lasers could be implemented. Within Lawrence Livermore Laboratories, two such laser systems, Shiva and Nova were designed. Both of them work by delivering high power bursts of laser light from multiple lasers onto a small deuterium-tritium pellet (Fig. 2a) [2]. These lasers, capable of extremely high power pulses, are arranged to strike the pellet symmetrically, creating the necessary inertial confinement conditions, imploding the fuel pellet (2b). The inertia of this implosion keeps the reaction confined as it attempts to escape outwards (2c). However, the huge power requirements for fusion to occur and the enormous cost of current lasers and laser technology make the hope of high-yield fusion seem pretty slim.
Figure 2 - lasers striking a fuel pellet, initiating an inertial confinement fusion.
But scientists at Sandia National Laboratories had an idea; an alternative to lasers as the source of inertial confinement. The proposed idea was a pulsed power system . . .