Scientists use sophisticated computer models and the results of
previous research to design an experiment.
Designers and engineers develop the target
based on the experiment’s requirements.
Technicians fabricate, assemble, and measure the components
to millionth-of-a-meter tolerances.
NIF targets are designed to provide diagnostics with line-of-sight
access to the capsule suspended inside the hohlraum.
The target is mounted on an inserter and placed in the center of the Target Chamber; many targets are cooled to just a few degrees above absolute zero.
Positioning the Diagnostics
Diagnostics are inserted into the 10-meter-diameter Target Chamber to capture the results of the experiment. More than 100 different diagnostics are available to record every aspect of NIF experiments.
The temporal shape, wavelength, and timing of the laser pulse are precisely set in the Master Oscillator Room. Pulses of a few billionths of a joule are amplified several billion times before being injected into NIF’s main laser amplifiers.
Control Room operators remotely align the laser beams and diagnostics
and perform the final shot countdown.
When the shot is fired, the NIF capacitor bays deliver 400 megajoules of stored electrical energy to the main laser’s 7,680 flashlamps.
In the laser bays, the amplifiers increase the one-joule input from the injection laser to nearly 4 million joules of infrared laser light.
In the Target Bay, the final optics assemblies convert the infrared light to about 2 million joules of high-energy ultraviolet light and direct the laser beams to the target at the center of the Target Chamber.
Triggering Nuclear Fusion
NIF’s lasers compress the fusion fuel to pressures that exceed 100 billion times Earth’s atmosphere and temperatures of more than 100 million Kelvin (180 million degrees Fahrenheit), forcing hydrogen atoms to fuse in a controlled thermonuclear reaction.
Data from NIF experiments (right) are analyzed on LLNL supercomputers and compared with model predictions (left), resulting in improved computer models and new experimental designs.
