SYDNEY, July 26 (Xinhua) — Australian scientists believe they are well on their way to solving one of the universe’s greatest mysteries, the nature of invisible dark matter.
The Oscillating Resonant Group AxioN (ORGAN) experiment, Australia’s first major dark matter detector, has just completed its search for a particle called an axion, which many cosmologists and physicists believe is a likely component of dark matter.
Dark matter, which is believed to make up a large proportion of the galaxy, does not absorb, reflect or emit electromagnetic radiation, making it exceptionally difficult to detect.
Explaining the project in a paper published on Tuesday in The Conversation, physicist Dr Ben McAllister of the University of Western Australia (UWA), said ORGAN had put new limits on the possible characteristics of axions and had therefore helped to reduce the elusive look for them
McAllister said scientists believed that axions can be converted into particles of light, known as photons, if they are subjected to a strong magnetic field.
“That’s good news, because that’s exactly what ORGAN does,” he said.
“It works out the right conditions for axion-photon conversion and looks for signals from weak photons, which are tiny flashes of light generated by dark matter passing through the detector.”
Before the creation of ORGAN, scientists were hampered by temperatures generated by magnetic fields that triggered random flashes of light, or noise, as they call it, that made it difficult to detect the weak signals of dark matter.
“To solve this, we placed our resonator in a ‘dilution refrigerator,'” he said. “This fancy refrigerator cools the experiment to cryogenic temperatures, about -273 (degrees) Celsius, which greatly reduces the noise”.
In a separate paper published Monday in SciTechDaily, McAllister expanded on his progress: “When we don’t see a small flash, as was the case this time, we instead put exclusion limits, where we rule out axions that would have the our experiment. has been sensitive.”
“Then we say to the rest of the dark matter community ‘there’s no dark matter here’ and go look for axions of a different mass.”
McAllister said the project was just the first phase of a multi-year action research with future work even more extensive.
“We are currently preparing the next experiment, which will be more sensitive and target a new mass range not yet explored,” he said.
Explaining the importance of his research, McAllister said: “We would never have discovered electricity, or radio waves, if we hadn’t pursued what, at the time, seemed like strange physical phenomena beyond our understanding.”
“Dark matter is the same.” Let’s end