In
"high energy density" (HED) experiments such as NOVA and the National
Ignition Facility, powerful laser beams enter holes and strike the inside wall
of a hohlraum, which is a small cylinder containing a pea-size fusion fuel capsule.
Laser energy heats the inside of the hohlraum creating x-rays that surround
the capsule, or target. The x-rays rapidly heat the capsule inside the hohlraum
(fig. 1) causing the capsule's surface to fly outward (fig. 2). This outward
force causes an opposing inward force that compresses the fusion fuel (hydrogen
isotopes) inside the capsule. When the compression reaches the center, temperatures
increase to 100 million degrees Centigrade, igniting the fusion fuel (fig. 3)
and producing a laser fusion thermonuclear burn that generates an energy output
much larger than the laser energy input, thus providing a large energy gain
(fig. 4).
Please
see Plasmas.org
for more information.
National
Ignitions Facility at Lawrence Livermore National Laboratory
Argonne
Wakefield Accerelator
General Atomics
Fusion Group
Accelerator and
Fusion Research
Sandia National
Laboratories