Page 393 - High Power Laser Handbook

362 So l i d - S t at e La s e r s The National Ignition Facility Laser 363

The Ligne d’Integration Laser (LIL) was completed in 2002 at
Cesta, France, by the French nuclear science directorate Commis-
sariat à l’Énergie Atomique (CEA). This four-beam prototype of the
240-beam Laser Mégajoule (LMJ) was designed, like NIF, to be capa-
ble of demonstrating inertial fusion ignition and gain. There has been
very active collaboration between NIF and LMJ designers, and we
have learned much from each other. A notable example is the devel-
opment at CEA of programmable spatial light modulators for detailed
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tailoring of the light that is launched into the large amplifiers. As of
this writing, NIF is in the process of installing these devices in the
front end of all beamlines.
NIF is the culmination of the experience gained at all of these facili-
ties over the years. Its fundamental requirements in terms of energy,
power, pulse-shaping finesse, far-field spot-size control, power
balance, and shot-to-shot reproducibility, among other criteria, were
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laid out in 1994. Its goal is to achieve fusion breakeven, with more
thermonuclear energy released than is delivered in the form of laser
energy, based on the understanding that has been developed by the
plasma-physics and target-coupling data gathered in previous
facilities.
Ceremonial groundbreaking occurred in May 1997, and by June
1999, the stadium-sized facility was sufficiently completed that the
10-m, 264,000-lb target chamber could be installed in the target bay.
The conventional facility was completed in September 2001, and in
December 2002, its first four beams were fired at 43-kJ IR in a 5-ns
pulse. On May 30, 2003, NIF set the first of its world records by firing
a single-beam 10.4-kJ, 3.5-ns UV pulse into its precision diagnostics
system, thus meeting its primary criteria for beam energy, uniformity,
and pulse-shaping capability. The first plasma-coupling experiments
were carried out in August 2003. On February 24 and 25, 2009, a spe-
cial subcommittee of the National Ignition Campaign (NIC) Review
Committee met with NIF scientists for “a formal performance review
of the status of the Laser System of NIF and the readiness of the Laser
System for its role in the National Ignition Campaign.” Their
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conclusion was “that each and every one of the laser performance
Completion Criteria, established under the NIF Project Completion
Criteria, has been met or exceeded.” 26

14.3 NIF Facility and Laser Overview
For more than a decade, up to 1000 engineers, scientists, technicians,
and skilled laborers, as well as more than 2300 vendors, have worked
on NIF. NIF’s 192-laser beamlines are housed in a building with a volume
of about 350,000 m . Figure 14.1 shows an aerial photograph of the NIF
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site, doctored to remove the roofs and to show the internal structure. In
the upper left is the optical assembly building, where final assembly,