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International Team Builds Particle Detector at South Pole

United States, Germany, Sweden, Belgium contribute to science project

An international team of scientists and engineers has taken a major step forward in building a detector, called IceCube, at the South Pole to observe subatomic particles called neutrinos.

IceCube is looking for neutrinos - ghostly, high-energy subatomic particles created in galactic collisions, distant black holes, quasars and a host of the most violent events in the cosmos.

The IceCube project is an international collaboration of scientists from more than 30 scientific organizations. More than a dozen U.S. universities also are involved, according to a March 21 press release from the U.S. National Science Foundation (NSF).

NSF is contributing more than $240 million to the international partnership that is building the $272-million detector. Germany, Sweden and Belgium also are making significant contributions to the project.

The University of Wisconsin-Madison is leading the drilling and science operations.

The scientists used a sophisticated hot-water drill to install hundreds of basketball-sized optical devices in the Antarctic ice sheet under the South Pole. The devices are composed of electronic sensors to sense light and circuit boards to gather and process data.

This array of devices eventually will form a detector that encompasses a cubic kilometer of ice. Theorists think an instrument of this size is needed to study neutrinos from distant astrophysical sources.

When fully operational, IceCube will use 4,200 light-sensing devices to sample neutrinos from the sky in the Northern Hemisphere.

The optical devices are put into deep holes bored by the unique hot-water drill. When the holes are drilled, 2.5-kilometer-long cables connected to the optical devices are frozen in place.

The devices act like light bulbs in reverse, gathering the light - called Cherenkov light after Russian physicist and Nobel Prize winner Pavel Cherenkov, who first observed the light - that is created when neutrinos collide with other particles.

The modules then relay data to the surface, where the information is processed and stored for analysis.

The IceCube detector is a powerful tool that will use neutrinos to search for dark matter, and could reveal new physical processes associated with the mysterious origin of the highest-energy particles in nature.

Dark matter comprises physical objects or particles that emit little or no detectable radiation of their own and are thought to exist because of unexplained gravitational forces observed on other astronomical objects.

Source: U.S. Department of State

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