This week the National Nuclear Security Administration
(NNSA), along with officials from the National Ignition Facility (NIF) at
Lawrence Livermore National Laboratory (LLNL), announced an important milestone
in the National Ignition Campaign (NIC) at the 51st annual meeting of the
American Physical Society Division of Plasma Physics in Atlanta.
Highlighting results from recent NIF tests, NNSA and LLNL
and its NIC partners—Los Alamos National Laboratory, the Laboratory for Laser
Energetics (LLE), General Atomics, and Sandia National Laboratories—showed that
NIF's laser beams can be effectively delivered and are capable of creating
sufficient x-ray energy to drive fuel implosion, an important step toward the
ultimate goal of fusion ignition. LLE also presented results showing the most
compressed fusion capsules to date.
The NIF was built as a part of the NNSA's program to ensure
the safety, security and effectiveness of the nuclear weapons stockpile without
underground testing. With NIF, scientists will be able to evaluate key
scientific assumptions in current computer models, obtain previously
unavailable data on how materials behave at temperatures and pressures like
those in the center of a star, and help validate NNSA's supercomputer
simulations by comparing code predictions against observations from laboratory
experiments.
Because of its groundbreaking advances in technology, NIF
also has the potential to produce breakthroughs in fields beyond national
security. It will help advance fusion energy technology, which could be an
element of making the United
States energy independent. It also will
enable scientists to better understand the makeup of stars in the universe and
planets both within and outside our solar system.
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This artist's rendering shows a NIF target pellet inside a hohlraum capsule with laser beams entering through openings on either end. The beams compress and heat the target to the necessary conditions for nuclear fusion to occur.
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"The developments announced this week demonstrate
exciting progress toward the grand scientific challenge that is fusion ignition
on the National Ignition Facility," said Brig. Gen. Garrett Harencak, NNSA
Principal Assistant Deputy Administrator for Military Application. "NIF
will be a cornerstone of a critical national security mission, ensuring the
continuing reliability of the U.S.
nuclear stockpile without underground nuclear testing, while also providing a
path to explore the frontiers of basic science, and potential technologies for
energy independence. It is a prime example of how our investment in nuclear
security is providing the tools to tackle a broad range of national challenges."
The results announced this week demonstrate that NIF is
capable of fulfilling a key requirement of the fusion process. To achieve
fusion, NIF will focus its 192 laser beams, in a few billionths of a second,
into a pencil-eraser-sized metal cylinder containing a small fuel capsule to
create a small star about the diameter of a human hair which, when successful,
releases more energy than the laser energy used to create it.
One of the key requirements for this process is to create
sufficient x-ray energy to drive the fuel implosion. In a series of experiments
that began shortly after the facility was dedicated in May, NIF researchers
have been focusing on characterizing the x-ray drive created in test targets.
Recent tests at the NIF have shown that the NIF laser beams can be effectively
delivered and are capable of heating the targets to the radiation temperatures
needed to drive fuel capsules to ignition conditions.
"These are very exciting results," said NIF
Director Ed Moses. "The NIF laser is proving to be robust with very
precise and repeatable performance. We have demonstrated most aspects of target
fabrication and are integrating and using the diagnostics we need for initial
ignition test experiments later next year."
NNSA and LLNL presented the data during the 51st annual
meeting of the American Physical Society Division of Plasma Physics. The
American Physical Society is the premier membership organization for
physicists.
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