Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Polar neutrino observatory takes a big step forward

22.03.2006


An international team of scientists and engineers has taken a major step toward completion of what will be the world’s preeminent cosmic neutrino observatory, harnessing a sophisticated hot-water drill to build an observatory under the South Pole that eventually will encompass a cubic kilometer of ice.



Scientists leading a consortium building the massive neutrino telescope known as IceCube say that this year they have nearly doubled the size of the detector now under construction at the National Science Foundation’s Amundsen-Scott South Pole Station.

NSF, through a joint program of its Office of Polar Programs and its Mathematical and Physical Sciences Directorate, is contributing more than $240 million to the international partnership that is building the detector, which will cost $272 million overall.


Although work can only take place from October through February-the fleeting and still frigid summer season at the Pole-the extent and pace of construction this year means that the observatory may soon begin scientific operations. IceCube is scheduled for completion in 2011.

"The news is good all around," says Francis Halzen, the University of Wisconsin-Madison physics professor leading the effort.

Halzen and others leading the effort report that IceCube- which depends on strings of light-sensing modules frozen deep in crystal clear Antarctic ice-has grown this austral summer by 480 basketball-sized optical modules. Deployed on long cables in 1.5-mile deep holes bored by a unique hot-water drill, the modules will be used to detect the fleeting but telltale signatures of high-energy cosmic neutrinos as they flit through the Earth.

Neutrinos are ghostly, high-energy subatomic particles created in galactic collisions, distant black holes, quasars and a zoo of the most violent events in the cosmos. They carry information that promises to peel back some of the mystery of the universe’s most enigmatic events such as gamma ray bursts, dark matter and supernovas.

But cosmic neutrinos-billions of which pass unnoticed through the Earth and indeed through the human body every day-are, by their very nature, extremely difficult for astrophysicists to detect. What is required is a very large detector to optimize the chances that scientists can catch a neutrino in the act of crashing into a proton or another subatomic particle.

When IceCube is completed, a cubic kilometer of the ice beneath the Pole will have been seeded with more than 4,200 optical sensors to capture telltale traces of the neutrinos and follow their tracks back to their distant points of origin. In addition, another 300 or so sensors will be deployed in tanks on the surface of the polar ice.

Once the holes are drilled, cables with the spherical digital optical modules-which are composed of electronics for sensing light and circuit boards for gathering and processing data-are lowered into the ice, where they are frozen in place. The modules act like light bulbs in reverse, gathering light created when neutrinos collide with other particles. The modules then relay data to the surface where the information is processed and stored for analysis.

When fully operational, IceCube will sample neutrinos from the sky in the Northern Hemisphere. The detector will use the Earth as a filter to exclude other types of neutrinos, such as those from the sun, which could confuse the detector. Its primary scientific mission will be to identify the sources and distribution of the highest energy neutrinos created by violent cosmic events.

IceCube is being constructed around an older, prototype neutrino telescope known as AMANDA for Antarctic Muon and Neutrino Detector Array. IceCube construction began in January 2005 when scientists drilled the first hole for the detector and deployed the first optical modules for the observatory.

"The digital optical modules deployed last year have now functioned for one year without failures," says Halzen. "They perform like a Swiss watch. But the big story of this season is the performance of the drill."

After working out kinks in the performance of the drill last year and at the beginning of the 2005-06 drilling season, and adding an extra drilling tower, the IceCube team was able this year to bore a total of eight deep holes into the Antarctic ice and deploy eight 60-module strings of sensors this season. Combined with the existing AMANDA array, IceCube currently consists of nearly 1,300 optical modules.

Although the new technologies used to create the detector are completely environmentally safe, the engineering challenges of working in the Polar environment-where temperatures fluctuate, on average, from minus 35 Fahrenheit in November to minus 16 Fahrenheit in February-are daunting. Even so, "all the major challenges encountered by drilling a first hole last season have been solved," says Halzen.

The IceCube array now is composed of nine strings and 16 surface detector stations, in addition to the still operational AMANDA array, making a scientific program possible, according to Jim Yeck, IceCube project director.

"We know that there is more work to be done, but let there be no doubt about what a remarkable accomplishment it is to safely install eight strings this season," Yeck says.

The newly installed modules are functioning and sending signals to the surface, Yeck says. IceCube scientists will continue to verify cable connections and surface electronics during the upcoming winter season at the South Pole.

Francis Halzen | EurekAlert!
Further information:
http://www.physics.wisc.edu

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>