Neutrinos and Dark Matter

PNNL chemist Isaac Arnquist examines ultra-low radiation copper cables specially created for sensitive physics detection experiments. Credit: Andrea Starr, Pacific Northwest National Laboratory



Ultra-low radiation cables reduce background noise for neutrino and dark matter detectors.

Imagine trying to tune a radio to a single station but instead encountering static noise and interfering signals from your own equipment. That is the challenge facing research teams searching for evidence of extremely rare events that could help understand the origin and nature of matter in the universe. 

It turns out that when you are trying to tune into some of the universe’s weakest signals, it helps to make your instruments very quiet.

Around the world, more than a dozen teams are listening for the pops and electronic sizzle that might mean they have finally tuned into the right channel. These scientists and engineers have gone to extraordinary lengths to shield their experiments from false signals created by cosmic radiation. 

Most such experiments are found in very inaccessible places—such as a mile underground in a nickel mine in Sudbury, Ontario, Canada, or in an abandoned gold mine in Lead, South Dakota—to shield them from naturally radioactive elements on Earth. 

However, one such source of fake signals comes from natural radioactivity in the very electronics that are designed to record potential signals.

Ultra-low radiation cables reduce background noise for neutrino and dark matter detectors.

Imagine trying to tune a radio to a single station but instead encountering static noise and interfering signals from your own equipment. That is the challenge facing research teams searching for evidence of extremely rare events that could help understand the origin and nature of matter in the universe. 

It turns out that when you are trying to tune into some of the universe’s weakest signals, it helps to make your instruments very quiet.

Around the world, more than a dozen teams are listening for the pops and electronic sizzle that might mean they have finally tuned into the right channel. These scientists and engineers have gone to extraordinary lengths to shield their experiments from false signals created by cosmic radiation. 

Most such experiments are found in very inaccessible places—such as a mile underground in a nickel mine in Sudbury, Ontario, Canada, or in an abandoned gold mine in Lead, South Dakota—to shield them from naturally radioactive elements on Earth. 

However, one such source of fake signals comes from natural radioactivity in the very electronics that are designed to record potential signals.  READ MORE...

Molten Salt Battery & Energy

Close-up of the freeze-thaw battery developed by the PNNL team. 

Credit: Andrea Starr/Pacific Northwest National Laboratory

During spring in the Pacific Northwest, meltwater from thawing snow rushes down rivers and the wind often blows hard. These forces spin the region’s many power turbines and generate a bounty of electricity at a time of mild temperatures and relatively low energy demand. But much of this seasonal surplus electricity—which could power air conditioners come summer—is lost because batteries cannot store it long enough.

Researchers at Pacific Northwest National Laboratory (PNNL), a Department of Energy national laboratory in Richland, Wash., are developing a battery that might solve this problem. In a recent paper published in Cell Reports Physical Science, they demonstrated how freezing and thawing a molten salt solution creates a rechargeable battery that can store energy cheaply and efficiently for weeks or months at a time. 

Such a capability is crucial to shifting the U.S. grid away from fossil fuels that release greenhouse gases and toward renewable energy. President Joe Biden has made it a goal to cut U.S. carbon emissions in half by 2030, which will necessitate a major ramp-up of wind, solar and other clean energy sources, as well as ways to store the energy they produce.

Most conventional batteries store energy as chemical reactions waiting to happen. When the battery is connected to an external circuit, electrons travel from one side of the battery to the other through that circuit, generating electricity. To compensate for the change, charged particles called ions move through the fluid, paste or solid material that separates the two sides of the battery. 

But even when the battery is not in use, the ions gradually diffuse across this material, which is called the electrolyte. As that happens over weeks or months, the battery loses energy. Some rechargeable batteries can lose almost a third of their stored charge in a single month.  READ MORE...