IceCube to help search for dark matter
An extraordinary underground observatory for subatomic particles has
been completed in a huge cube of ice one kilometre on each side deep
under the South Pole, researchers said.
Building the IceCube, the world's largest neutrino observatory, has
taken a gruelling decade of work in the Antarctic tundra and will help
scientists study space particles in the search for dark matter,
invisible material that makes up most of the Universe's mass.
A module prepred to place beneath the sea in icecap searth. AFP |
The observatory, located 1,400 metres underground near the US
Amundsen-Scott South Pole Station, cost more than 270 million dollars,
according to the US National Science Foundation (NSF).
The cube is a network of 5,160 optical sensors, each about the size
of a basketball, which have been suspended on cables in 86 holes bored
into the ice with a specially-designed hot-water drill.
NSF said the final sensor was installed in the cube, which is one
kilometre (0.62 miles) long in each direction, on December 18.
Once in place they will be forever embedded in the permafrost as the
drill holes fill with ice.
The point of the exercise is to study neutrinos, subatomic particles
that travel at close to the speed of light but are so small they can
pass through solid matter without colliding with any molecules.
Scientists believe neutrinos were first created during the Big Bang
and are still generated by nuclear reactions in suns and when a dying
star explodes, creating a supernova.
Trillions of them pass through the entire planet all the time without
leaving a trace, but the IceCube seeks to detect the blue light emitted
when an occasional neutrino crashes into an atom in the ice.
"Antarctic polar ice has turned out to be an ideal medium for
detecting neutrinos," the NSF said in a statement announcing the
project's completion.
"It is exceptionally pure, transparent and free of radioactivity."
Scientists have hailed the IceCube as a milestone for international
research and say studying neutrinos will help them understand the
origins of the Universe.
"From its vantage point at the end of the world, IceCube provides an
innovative means to investigate the properties of fundamental particles
that originate in some of the most spectacular phenomena in the
Universe," NSF said.
AFP
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