May 17, 2019
In this time-integrated photograph of an X-ray diffraction experiment, giant lasers focus on the water sample, sitting on the front plate of the diagnostic used to record diffraction patterns, to compress it into the superionic phase.
At the Laboratory for Laser Energetics in Brighton, New York, one of the world’s most powerful lasers recently blasted a droplet of water, creating a shock wave that raised the water’s pressure to millions of atmospheres and its temperature to thousands of degrees. X-rays that beamed through the droplet in the same fraction of a second offered humanity’s first glimpse of water under those extreme conditions.
The X-rays revealed that the water inside the shock wave didn’t become a superheated liquid or gas. But, just as physicists squinting at screens in an adjacent room had expected, the atoms froze solid, forming crystalline ice.
“You hear the shot,” said Marius Millot of Lawrence Livermore National Laboratory and “right away you see that something interesting was happening.” Millot co-led the experiment with Federica Coppari, also of Lawrence Livermore.
The findings confirm the existence of “superionic ice,” a new phase of water with bizarre properties. Unlike the familiar ice found in your freezer or at the north pole, superionic ice is black and hot. A cube of it would weigh four times as much as a normal one. It was first theoretically predicted more than 30 years ago, and although it has never been seen until now, scientists think it might be among the most abundant forms of water in the universe.
NASA and Lawrence Livermore researchers are working on a project to deflect asteroids heading toward a collision with Earth.
If space scientists become aware of the threat of a hazardous asteroid barreling toward Earth early enough, they might be able to give it enough of a nudge to knock it off its disastrous course, long before it approached Earth. That's the idea behind NASA's Double Asteroid Redirection Test, known as DART. It's a spacecraft that's set to launch in 2021, on course to deliberately smash into an asteroid in the fall of 2022.
"It will be the first-ever asteroid deflection test," said Megan Bruck Syal, a physicist at Lawrence Livermore National Laboratory and member of the DART team. She points out that there could be tens of thousands of asteroids as big as DART's target, and the majority of them haven't been discovered, let alone tracked, yet.
In the case of a real-life killer asteroid, people may only get only one shot to deflect it, so there's plenty of pressure to get the math right. There's also a chance that throwing a spacecraft at the asteroid won't be enough. "You'd have to push on it so hard that it would start to come apart," Bruck Syal said.
Then people would consider blowing up the asteroid and scattering the fragments. In a last-ditch effort, scientists might actually have to deploy nuclear weapons. "But the more warning time you have, the better," she said.
Scientists at Lawrence Livermore and the University of Nevada in Las Vegas report a previously unknown pressure-induced phase transformation in TATB above 4 GPa (40,000 atmospheres of pressure). Image by Adam Connell/LLNL
Scientists at Lawrence Livermore, in collaboration with the University of Nevada Las Vegas, discovered a previously unknown pressure-induced phase transition for TATB that can help predict detonation performance and explosive safety.
1,3,5-Triamino-2,4,6-trinitrobenzene (TATB), the industry standard for a high insensitive explosive, stands out as the optimal choice when safety (insensitivity) is paramount. Among similar materials with comparable explosive energy release, TATB is remarkably difficult to initiate shock and has a low sensitivity to friction. The causes of this unusual behavior are hidden in the structural evolution at high pressure of TATB.
Supercomputer simulations of explosives detonating, running on the world’s most powerful machines at LLNL, depend on knowing the exact locations of the atoms in the crystal structure of an explosive. Accurate knowledge of atomic arrangement under pressure is the cornerstone for predicting the detonation performance and safety of an explosive.
The team conducted experiments using a diamond anvil cell, which compressed individual TATB crystals at a pressure of more than 25 GPa (250,000 times atmospheric pressure). According to all previous experimental and theoretical studies, it was believed that the atomic arrangement in the crystal structure of TATB remains the same under pressure. The project team challenged the consensus in the field with the aim of clarifying TATB's high-pressure structural behavior.
Solar energy increased by 22 percent from 2017 to 2018.
Americans used more energy in 2018 than in any other year, according to the most recent energy flowchart released by Lawrence Livermore National Laboratory. (Each year, the Laboratory releases energy flow charts that illustrate the nation’s consumption and use of energy.) Overall total energy consumption rose to 101.2 quadrillion BTU (or “quads”). The prior record, set in 2007, was 101.0 quads. Energy use went up by 3.6 percent from 2017, which also is the largest annual increase since 2010.
Americans used 3.5 quads (quadrillion BTU) more in 2018 than in 2017. A BTU, or British Thermal Unit, is a unit of measurement for energy; 3,400 BTUs is equivalent to about 1 kilowatt-hour.
The largest increases in energy supply came from natural gas, wind and solar energy. In 2018, wind use was up 0.18 quads (7.6 percent) and solar was up 0.18 quads (22 percent). Over the last decade (between 2008 and 2018), total renewable energy production has doubled, including a five-fold increase in wind power and a 48-fold increase in solar. Wind and solar combined now produce more electricity than hydroelectric power, which dominated renewable energy for decades.
Researchers hope to learn more about how countries might act in nuclear warfare scenarios. Image by: Lorenzo Vidali/Sandia National Laboratories
LLNL researchers, in collaboration with UC Berkeley and Sandia National Laboratories, want the public to understand the risks of a nuclear conflict.
They designed a game to do just that. It explores how various weapons capabilities, such as low-yield, high-precision nuclear weapons, may affect the behavior of different actors in an escalating global conflict.
Starting May 15, SIGNAL became available during open play windows — currently scheduled from 1 to 5 p.m. PDT every Wednesday and Thursday — for anyone to log on and play. The researchers may expand those times if there is enough interest.
On its surface, SIGNAL looks like many other military strategy board games: Each online player represents one of three hypothetical countries, and the goal of the game is to maintain territorial integrity while amassing more resources and infrastructure than your opponents. Players have the opportunity to “signal” their intent to take actions such as building civilian and military infrastructure or attacking an opponent with conventional, cyber or nuclear weapons. Players also can negotiate trades and agreements with other players.