Tiny British lab challenging collider project
The team hope to pinpoint dark matter — the cosmic glue that is thought to bind together the universe.
If they succeed, they could snatch some of the glory from scientists operating the €4.4 billion Large Hadron Collider (LHC), which is switched on today.
Dark matter is the name given to the mysterious unseen particles thought to exist all around us and throughout space.
Proving its existence would account for some of the vast amount of “missing matter” we can see only by its effect on other things.
And it would be a huge stride forward for scientists seeking to understand how the universe works.
The scientists operating the LHC, a 27km (16.8 miles) circumference particle accelerator built beneath the Franco-Swiss border near Geneva, expect to trace dark matter within two years. But their rivals, based in a €2.5 million underground laboratory in Cleveland, could succeed in half that time.
Housed at the bottom of Boulby potash mine, where millions of tons of minerals used for fertiliser and for gritting roads is extracted every year, researchers from Edinburgh University and Imperial College London have, with US and Russian collaboration, built what is billed as the most sensitive particle detection machine known to science.
Their Zeplin-3 project will spot “wimps” — weakly interacting massive particles — which are as yet unobserved sub-atomic particles scientists believe may account for dark matter.
To do this, they have filled a large tank with the inert gas xenon and fitted it with detectors that can spot the flashes of light that should be produced when wimps occasionally strike xenon atoms.
Boulby researcher Dr Sean Paling said: “We could be the first people in the world to observe dark matter.
“The laboratory is 3,000 feet below ground to be shielded from cosmic rays. But the rays cannot penetrate half-a-mile of rock. The detector is also surrounded by plastic neutron shielding and lead gamma ray shielding.
“It means there is 1,000,000 times less interference than on the surface, making it the most sensitive detector in the world.
“Every so often a wimp will bounce off an atom in the detector, creating a very tiny little signal.
“Without other particles battering the instruments, we hope to pinpoint wimps when they make these very rare interactions with normal matter.”
Dr Paling said: “The LHC collider in Geneva hope to create wimps from other particles. But what we are doing is different.
“We want to observe them as they occur ‘in the wild’ — which will prove they exist naturally and they surround us.
“That will answer a massive question which has been puzzling science. We know now we understand just 20% of what the universe is made of.
“But there is something out there which is bizarrely heavy, which is invisibly pulling stuff around the universe, of which the effects are blatant.
“We will prove that this missing 80% mass in the universe is due to these particles.” The LHC machine has taken 10 years to build and is roughly the size of London Underground’s Circle Line.
Zeplin-3 must be kept scrupulously clean even though it has been built inside a working potash pit.
“It is a different world down here,” Dr Paling said. “You have to put on mining gear, fulfil careful safety requirements and take great care not to get lost in all the different galleries.
“But once you’re underground it’s just like any other lab; except there are no windows.”
