Inertial fusion requires a thousand-fold compression of matter to ultrahigh densities and temperatures. The Sun and other stars use gravity to do the job and fuse hydrogen into helium. To mimic the effect on Earth, scientists at Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) use the world’s most powerful bank of lasers to squeeze isotopes of hydrogen—deuterium and tritium—in a 2-mm-wide capsule.
The facility trains 192 laser beams into a 1-cm-tall, hollow, gold-lined cylinder known as a hohlraum, shown in figure 1, that suspends the capsule inside it. After absorbing UV-laser light, the hohlraum’s interior wall reradiates a flux of soft x rays. Within 8 ns, those x rays accelerate and compress the hydrogen isotopes into a hot spot half the width of a human hair at a temperature of 60 million kelvin and a pressure of 350 GPa.
To read more, click here.