(AGENPARL) – ven 13 ottobre 2023 A weekly compendium of media reports on science and technology achievements
at Lawrence Livermore National Laboratory. Though the Laboratory reviews
items for overall accuracy, the reporting organizations are responsible for
the content in the links below.
….. LLNL Report, Oct. 13, 2023
New research reaffirms that ancient human footprints found in White Sands
National Park, New Mexico, date to between 21,000 and 23,000 years ago,
placing humans in North America thousands of years earlier than once thought.
Image courtesy of USGS.
… Tracking ice age footprints

Hidden within the seemingly barren expanse of White Sands National Park in
New Mexico are human footprints. But these impressions are much more than
random tracks: They are ancient vignettes cast in gypsum-rich sand.
But one question has plagued researchers studying these prints. Exactly how
long ago were they made? A paper published in 2021 offered a surprising
answer: Humans could have pressed their feet in the sand as early as 21,000
to 23,000 years ago, making the tracks some of the oldest evidence yet found
of people in the Americas.
The result brought both excitement and skepticism, with calls for additional
tests to back up the astonishing claims. A new study involved additional
methods to determine the age of the tracks and adds to the evidence for those
surprisingly ancient dates.
The dates for human footprints at White Sands place people deep in the North
American continent at the height of the Last Glacial Maximum. During that
time, ice sheets up to two miles thick were thought to be barricades to
passage from Siberia over the Bering Land Bridge.
The nearly yearlong process revealed pollen from a verdant landscape when
cooler temperatures prevailed, as would be expected during the Last Glacial
Maximum. Fir, spruce, pine and sagebrush abounded. The largest of these
pollen grains, mostly pine, was subjected to carbon analysis at Lawrence
Livermore National Laboratory. The team also worked on determining the date
of a layer of the White Sands sediments using a method known as optically
stimulated luminescence that, in essence, reveals how long quartz sand has
sat beneath the surface.
Read More

An operational test launch of an Air Force Global Strike Command unarmed
Minuteman III intercontinental ballistic missile launched from Vandenberg
Space Force Base, Calif., on Wednesday, Sept. 6. Image courtesy of Airman 1st
Class Kadielle Shaw/U.S. Space Force.
… A snapshot in time
https://www.forbes.com/sites/erictegler/2023/10/06/americas-aged-nuclear-weapons-may-not-work-a-massive-new-machine-will-image-them/?sh=6494d62b41c8
The U.S. last produced nuclear warheads in the 1980s. It cannot presently
produce any more. Sandia National Laboratories and other national labs
including Lawrence Livermore have developed a huge machine to test the old
weapons and validate future designs.
The machine, called Scorpius, is one hundred yards in length and will operate
1,000 feet below the Nevada desert. In essence, it’s a giant $1.8 billion
X-ray machine which will capture snapshots in time of plutonium as it is
compressed with high explosives, creating conditions that exist just prior to
a nuclear explosion.
That’s what happens when a nuclear warhead detonates on or over its target.
Up until 1992, when a nuclear testing moratorium was agreed to by President
George H.W. Bush, underground test implosions of nuclear warheads confirmed
the reliability of weapons in the existing nuclear stockpile and the
viability of new warhead designs.
Since those days 30-plus years ago, America has relied on computer
simulations to theoretically describe the hydrodynamics of plutonium in
nuclear warheads as they age. Those simulations are based on above-ground
facility tests of the implosive behaviors of surrogate materials like
tungsten. But their inherent differences with plutonium cannot be accurately
accounted for.
Read More
https://www.forbes.com/sites/erictegler/2023/10/06/americas-aged-nuclear-weapons-may-not-work-a-massive-new-machine-will-image-them/?sh=6494d62b41c8
The National Ignition Facility’s preamplifier module increases the laser
energy as it travels to the target chamber.
… Break on through for the second time
https://www.reuters.com/business/energy/us-scientists-repeat-fusion-power-breakthrough-ft-2023-08-06/
Lawrence Livermore National Laboratory scientists have achieved net energy
gain in a fusion reaction for the second time since December.
The Lab achieved a net energy gain in a fusion experiment using lasers on
Dec. 5, 2022. The scientists focused a laser on a target of fuel to fuse two
light atoms into a denser one, releasing the energy. That experiment briefly
achieved what’s known as fusion ignition by generating 3.15 megajoules of
energy output after the laser delivered 2.05 megajoules to the target, In
other words, it produced more energy from fusion than the laser energy used
to drive.
Scientists repeated the fusion ignition breakthrough in an experiment at the
National Ignition Facility (NIF) on July 30 that produced a higher energy
yield than in December. All the stars aligned, and a shot yielded 3.88 MJ,
89% more energy than the lasers injected. **
Read More
https://www.reuters.com/business/energy/us-scientists-repeat-fusion-power-breakthrough-ft-2023-08-06/
LLNL will co-lead the “Center for Coupled Chemo-Mechanics of Cementitious
Composites” (CM4) and will lead “Terraforming Soil,” both part of the
Department of Energy Office of Science Energy Earthshot program.
… Taking a shot at clean energy

DOE announces $264 million for basic research in support of Energy Earthshots™

The Department of Energy (DOE) has alloted $264 million in funding for 29
projects to develop solutions for the scientific challenges underlying
DOE’s Energy Earthshots™ Initiative to advance clean energy
technologies within the decade. The department launched the Energy Earthshots
Initiative to spur decarbonization efforts that will help the United States
meet President Biden’s ambitious climate and clean energy goals, including
a 50% reduction in carbon emissions by 2030 and a net-zero carbon economy by
2050.
The Energy Earthshots™ connect DOE’s basic science and energy technology
offices to accelerate innovations toward more abundant, affordable and
reliable clean energy solutions. These efforts seek to revolutionize many
sectors across the United States and will rely on fundamental science and
innovative technology to be successful.
The Energy Earthshot Research Centers will support multi-institutional,
multi-disciplinary teams addressing key basic research challenges relevant to
the Energy Earthshots. The centers will be housed at eight DOE National
Laboratories and will receive a combined $195 million across four years.
Lawrence Livermore National Laboratory will lead the center called
“Terraforming Soil EERC: Accelerating Soil-Based Carbon Drawdown Through
Advanced Genomics and Geochemistry.”
Read More

DOE announces $264 million for basic research in support of Energy Earthshots™

Illustration of an intense laser pulse hitting a diamond crystal from top
right, driving elastic and plastic waves (curved lines) through the material.
Photo courtesy of Greg Stewart/SLAC National Accelerator Laboratory
… Faster than the speed of sound
https://phys.org/news/2023-10-defects-diamond-faster.html
Researchers have discovered that tiny linear defects can propagate through a
material faster than sound waves do.
These linear defects, or dislocations, are what give metals their strength
and workability, but they also can make materials fail catastrophically —
which is what happens every time you pop the pull tab on a can of soda. The
fact that they can travel so fast gives scientists a new appreciation of the
unusual types of damage they might do to a broad range of materials in
extreme conditions — from rock ripped apart by an earthquake rupture to
aircraft shielding materials deformed by extreme stress,
Scientists have been debating whether dislocations can travel through
materials faster than sound does for nearly 60 years. A number of studies
concluded that they could not. But some computer models indicated that yes,
they could, provided that they started out moving at faster-than-sound speed.
Getting them instantaneously up to this speed would require a tremendous
shock. For one thing, sound travels a lot faster through solid materials than
it does through air or water, depending on the nature and temperature of the
material, among other factors. While the speed of sound through air is
generally given as 761 mph, it’s 3,355 mph through water and an incredible
40,000 mph in diamond, the hardest material of all.
To get the first direct images of how fast dislocations can travel, Lawrence
Livermore and SLAC National Accelerator Laboratory performed X-ray electron
laser experiments on tiny crystals of synthetic diamond.
When dislocations move faster than sound speed, they behave quite differently
and result in unexpected failures that have thus far only been modeled.
Without measurements, no one knows how much damage those ultrafast
dislocations can do.
Read More https://phys.org/news/2023-10-defects-diamond-faster.html
——————————————————————————
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