Lab Report

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The Lab Report is 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.

Dec. 4, 2020

target chamber

In the target chamber of the National Ignition Facility, 192 laser beams are focused on pellets of fusion fuel the size of peppercorns.

Go for the burn

In October 2010, in a building the size of three U.S. football fields, researchers at the Lawrence Livermore National Laboratory powered up 192 laser beams, focused their energy into a pulse and fired it at a pellet of nuclear fuel the size of a peppercorn. So began a campaign by the National Ignition Facility (NIF) to achieve the goal it is named for: igniting a fusion reaction that produces more energy than the laser puts in.

A decade and nearly 3,000 shots later, NIF scientists are exploring new target designs and laser pulse shapes, along with better tools to monitor the miniature explosions, NIF researchers believe they are close to an important intermediate milestone known as “burning plasma”: a fusion burn sustained by the heat of the reaction itself rather than the input of laser energy.

Self-heating is key to burning up all the fuel and getting runaway energy gain. Once NIF reaches the threshold, simulations suggest it will have an easier path to ignition, says Mark Herrmann, who oversees Livermore’s fusion program. “We’re pushing as hard as we can,” he said. “You can feel the acceleration in our understanding.”

glass

Artistic rendering of an aspirational future automated production process for custom GRIN optics, showing multi-material 3D printing of a tailored composition optic preform, conversion to glass via heat treatment, polishing and inspection of the final optics with refractive index gradients. Image by Jacob Long and Brian Chavez.

New optics benefit specialized eyewear

Researchers at Lawrence Livermore used multimaterial 3D printing to develop tailored gradient refractive index glass optics, delivering a result that could enable the manufacture of improved military specialized eyewear and virtual reality goggles.

The technique has a variety of conventional and unconventional optical properties in a flat glass component, expanding the versatility in performance of environmentally stable glass materials.

The team tailored the gradient in material compositions by controlling the ratio of two different glass-forming pastes or “inks” blended together inline using the direct ink writing method of 3D printing. After completing the composition-varying optical preform, the scientists densified it to glass. The material, they said, can be finished using conventional optical polishing methods.

sierra

Sierra is one of Lawrence Livermore National Laboratory's supercomputers that requires massive amounts of storage to handle the data the computer rushes out. Photo by Randy Wong/LLNL

Mind the store

When it comes to advanced technologies at the high end of computing, networking and storage, Lawrence Livermore is one of the world’s pathfinding testbeds. Trying new things at scale is a big part of the mandate for the Lab, which among other things, is the Department of Energy/National Nuclear Security Administration’s site for running the simulations and models that manage the effectiveness of the U.S. military’s nuclear weapons arsenal.

While Lawrence Livermore certainly has its fair share of capability-class supercomputers at the top of the Top 500 charts, the Lab has a lot of different systems, which are used for both classified and unclassified work, and it has more than 250 petabytes of storage that holds the data for these many systems.

“We have a little bit of everything,” said Robin Goldstone, HPC strategist in LLNL’s Advanced Technologies Office. “We try to have our file systems be mounted across all of our clusters — the exception being against these very large systems like Sierra where that file system is dedicated to that computing system. But in general, our users move around from one system to another, and they use different systems depending on availability. In some cases, there is specific hardware that they might want, and they want to have their data with them wherever they go. And it’s advantageous to use as well because otherwise they are going to make copies of it everywhere.”

microbes

The LLNL Biosecurity Science Focus Area seeks to design multilayered containment strategies to safeguard the deployment of engineered microbes in the rhizosphere.

global bio defense

Keeping an eye on microbes

To reduce the risk of unintended ecological consequences from environmentally deployed, genetically engineered microorganisms (GEMS), LLNL scientists and collaborators are developing built-in “security mechanisms” that ensure they function where and when needed.

The team hopes to stabilize GEMs to prevent the transfer of potentially “invasive traits” to neighboring native microorganisms and to control the niche-specific function of GEMs for safer and more effective environmental applications.

The need for biocontainment is especially relevant for environmental biotechnologies for sustainable development of bioenergy crops and carbon sequestration. The microbiota colonizing the rhizosphere of plant roots, especially the plant-benefiting microorganisms (PBMs), contribute to plant growth and modulate soil carbon input, release and storage. Genetic engineering approaches have been used for enhancing the beneficial traits of PBMs, such as nutrient acquisition and drought resistance.

membrane

A wafer-scale composite membrane made of vertically aligned, single-walled carbon nanotubes embedded in a parylene-N polymer matrix.

Living large in a small world

Lawrence Livermore scientists have created the largest defect-free membranes from single-walled carbon nanotubes.

Growing these high density, cylindrical molecules on 4-inch silicon wafers and using them to create membranes with exceptional transport properties, could benefit a whole lot of low-energy alternatives in applications such as desalination, pharmaceutical recovery, purification and waste treatment.

As part of their research, the scientists — under the guidance of senior Livermore scientist Francesco Fornasiero — managed to fully exploit the unique mass transport properties of carbon nanotubes as flow channels. 

At more than 50,000 times thinner than a human hair, these tiny channels — unlike conventional porous materials — allow for exceptionally fast gas and liquid flow that gets even faster as the tubes get smaller.