LAB REPORT

Science and Technology Making Headlines

June 21, 2024


Sierra

Many supercomputers such as LLNL’s Sierra are running much longer that the typical lifespan. (Photo: Randy Wong/LLNL)

It’s alive

Laboratories are running supercomputers for much longer, beyond the typical lifespan, as vendors prematurely deprecate the hardware and stop providing support. A typical supercomputer lifecycle is about five to six years. However, Japan-based RIKEN is planning to run its existing Fugaku for 10 years, and Lawrence Livermore National Lab (LLNL) has some systems running for 7-10 years in some cases.

“We plan on extending the lifetime of our machines,” said Satoshi Matsuoka, director at Japan’s RIKEN Center for Computational Science, during a panel discussion on sustainability of supercomputing at ISC 2024.

LLNL plans for a five-year lifespan for systems, as hardware maintenance typically becomes cost-prohibitive beyond that point. “We run systems … in practice, it’s about 7 to 8 years. We’ve run several systems for 10 years,” said Bronis de Supinski, chief technology officer at LLNL.

The decision to retire supercomputers largely depends on the energy efficiency and power-performance benefits of newer systems.


exoplanet core

LLNL researchers and collaborators observed a phase transition in magnesium oxide that is believed to reside in the interiors of Super-Earths, planets with masses and radii larger than Earth but smaller than ice giants like Neptune. (Image: Adobe Stock)


 

A dynamic transition in exoplanets

Researchers from Lawrence Livermore National Laboratory and Johns Hopkins University have discovered new information about the interiors of super-Earth exoplanets. The study focuses on magnesium oxide (MgO), a key component of Earth's lower mantle, which is believed to play a similar role in the mantles of large rocky exoplanets. MgO, known for its rock salt (B1) crystal structure, undergoes significant changes under extreme conditions, which has long intrigued scientists.

Super-Earths, which have masses and radii larger than Earth but smaller than Neptune, are thought to have compositions similar to terrestrial planets in our solar system. Under the extreme pressures and temperatures within their mantles, MgO is expected to transform from its B1 structure to a cesium chloride (B2) structure. This transformation greatly affects MgO's properties, including a decrease in viscosity, impacting the planet's internal dynamics.

To determine the pressure at which this transition happens, the LLNL team and collaborators developed a new experimental platform. This combines laser-shock compression with simultaneous measurements of pressure, crystal structure, temperature, microstructural texture and density.


Li, Mayali

Wei Li and Xavier Mayali used the NanoSims to measure nitrogen incorporation and exchange at single cell resolution of harmful algal blooms from Lake Erie. (Photo: Blaise Dorous/LLNL)

Understanding Lake Erie’s algal threats

A new study led by Lawrence Livermore scientists and University of Toledo professors and students aims to better understand the harmful algal blooms in Lake Erie. Algal blooms are a persistent issue for the lake, posing risks to the health of both the local ecosystem and those who use the lake for recreation.

Dragan Isailovic, a chemistry and biochemistry professor at the University of Toledo, explained that their collaboration with Lawrence Livermore allows them to focus on one specific type of bacteria. “We are investigating how the microbiome, including other types of bacteria, influences the growth of microcystic aeruginosa,” Isaialovic said.

The toxins emitted during these algal blooms can lead to serious consequences for aquatic life and humans. Exposure to microcystins can result in cell death, animal death, and even human death.

The team investigated the role of the microbiome in the production of nitrogen that supports Cyanobacteria growth. Much of this nitrogen comes from inorganic sources, notably from fertilizers.

By exploring these interactions further, the researchers hope to develop better strategies to prevent the formation of harmful algal blooms in the future.


quantum nuclear reactions

A depiction of the collision of two neutrons simulated on a quantum chip at the Advanced Quantum Testbed. (Image: Sofia Quaglioni/LLNL)

Quantum computing nuclear reaction rates

Scientists from Lawrence Livermore National Laboratory developed an algorithm to simulate nuclear reaction rates, which are tough to make in a lab, to collect data to maintain the nuclear weapons stockpile.

The hybrid computing scheme “successfully” simulated the scattering of two neutrons, which can be used to compute nuclear reaction rates, according to a press release by the National Nuclear Security Administration (NNSA). 

Researchers hope that developing this method could support NNSA in collecting data, alongside subcritical experiments, to ensure the reliability of the U.S.’s warheads without nuclear weapons testing. Since the Comprehensive Test Ban Treaty of 1992, NNSA has performed 33 subcritical experiments in Nevada.


earth temps

In the Arctic Ocean, sea ice reached its minimum extent of 1.44 million square miles (3.74 million square kilometers) on Sept. 15, 2020 - the second lowest extent since modern record-keeping began. (Image: NASA's Scientific Visualization Studio)

A force of nature

When comparing model simulations of recent Earth warming with real-world observations, differences can arise due to several factors, including model errors in the simulated response to rising greenhouse gases and natural fluctuations within the climate system.

In an effort to quantify the role of natural fluctuations in differences between models and observations, Lawrence Livermore National Laboratory scientist Stephen Po-Chedley and his collaborators found unique patterns of temperature trends associated with natural climate variability for the period 1980–2022.

The relative role of different drivers of model-observation discrepancies in the warming pattern has important implications for our understanding of climate sensitivity as well as regional climate changes, said Po-Chedley, co-author of the study. This work shows that natural variations in Earths climate likely contribute to key differences in the pattern of simulated

Computer with email graphic

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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.