Physicists Eye Electrically-Charged Plasma as a 'Radio' to Listen for Elusive Dark Matter
Scientists at the Max Planck Institute for Physics and Stockholm University are teaming up to scan for dark matter using plasma, and they're putting it in writing: Phys.org reports that the proposal was published in the peer-reviewed scientific journal Physical Review Letters.
Researchers are focusing on axions, which are the most plausible explanation for dark matter – and currently a theoretical explanation as the force that binds protons and neutrons thus making up 85% of the known universe. Axions aren't so much particles as they are (theoretical) energy waves permeating space. Whoever proves axions and dark matter exist will doubtless add the phrase "Nobel laureate" after their name.
Here is how they plan to do it: using wires thinner than a human hair and a powerful magnet, scientists will electrically "tune" plasma to conduct electricity and generate a magnetic field. By adjusting the frequency in the plasma, scientists hope to trigger axions to create their very own (and very small) electrical fields in response that then stimulate vibrations in the plasma. In other words: we won't be able to see them, but we will see the effect they have within the plasma.
"Finding the axion is a bit like tuning a radio: You have to tune your antenna until you pick up the right frequency. Rather than music, experimentalists would be rewarded with 'hearing' the dark matter that the Earth is traveling through," explained study author Dr. Alexander Millar of Stockholm University. "This is totally a new way to look for dark matter, and will help us search for one of the strongest dark matter candidates in areas that are just completely unexplored. Building a tuneable plasma would allow us to make much larger experiments than traditional techniques, giving much stronger signals at high frequencies."