1.   Plutonium, a silvery, manmade metal, is the primary fuel for nuclear weapons, providing a burst of energy that triggers a larger fusion explosion.

2.   The device is to generate miniature thermonuclear fusion explosions for studying the workings and reliability of hydrogen bombs.

3.   The resulting compression of the fuel within the capsule heats it to tens of millions of degrees, thereby, in principle, igniting a fusion explosion.

4.   That fission explosion in turn compresses a second component, of light atoms, which fuse and give off heat in an even greater fusion explosion.