Scientists have confirmed that a smartphone can detect very high-energy cosmic rays that hit the Earth from space, unfolding huge potential that can be tapped for use in case of a nuclear attack or leak that was witnessed in Japan in 2011 after tsunami.
Researchers from University of California have tested that a smartphone camera can detect high energy photons and particles of the sort produced by cosmic rays. Testing with radioactive isotopes of radium, cobalt, and cesium showed that the detector easily picked up gamma rays.
When the scientists also put a phone inside a lead box, it could detect high energy particles. Next, the researchers took a phone up on a commercial flight and were able to obtain a particle track across the detector.
How it Works?
The UC team led by UC Irvine physicist Daniel Whiteson and UC Davis physicist Michael Mulhearn has designed an app to turn the global network of smartphones into a planet-sized cosmic ray detector, according to a paper posted on physics website arXiv.
A long-standing puzzle in astrophysics is the source of ultra-high-energy particles from space that hit Earth called cosmic rays, which are up to a billion times more energetic than particles at CERN’s Large Hadron Collider.
They strike the atmosphere and cause an enormous shower of other particles, mostly muons, electrons and photons, over a wide area. Though they were discovered decades ago, cosmic rays at these high energies are very rare, making it difficult to pinpoint where in the universe they originated.
“Whole square kilometers can be drenched in these particles for a few milliseconds,” said Whiteson, associate professor of physics & astronomy at UCI. “The mystery is nobody knows where these crazy, high-energy particles are coming from or what’s making them so energetic. But they can be captured by technology in smartphones’ cameras.”
The app, dubbed CRAYFIS (Cosmic Rays Found in Smartphones), collects data when the phone is connected to a power source and has not been used for several minutes, in order to not interfere with normal phone usage or drain battery levels.
Anyone with an Android or iOS smartphone or tablet will be able to participate in the detector network. If an individual’s phone gathers data used in a scientific paper, he or she will be offered authorship. The app can also run in anonymous mode.
The silicon-based sensors in smartphone cameras use the same principles as detectors at CERN and elsewhere to identify the particles. But because the particles arrive so infrequently, a very large detector – such as a global network of smartphones – is needed.
As a side benefit, the same data can be used to calculate local levels of radiation from radon or other sources and function as an alarm system. The network of phones could provide a real-time radiation weather map, following the movement of plumes, for instance.
While it has recently been shown elsewhere that individual smartphones can spot particles, this is the first attempt to demonstrate that if enough devices are connected, a networked, worldwide detector can rival or exceed the scientific capabilities of huge, dedicated cosmic ray experiment sites such as the Auger Experiment in South America.
According to researchers, if they can get 1,000 active cell phones within a square km area, they will be able to detect nearly all of the high energy cosmic rays that strike the atmosphere.
The team has been working on the project for nearly a year and the co-authors of the paper are Chase Shimmin and Kyle Brodie of UCI and Dustin Burns of UC Davis.