By John Lucas, jplucas@facstaff.wisc.edu
The university is slated to receive $15 million in federal funding for
the first phase of a groundbreaking, Antarctica-based neutrino telescope.
IceCube [http://www.ssec.wisc.edu/a3ri/icecube/], as the observatory is
known, is a next-generation subatomic particle telescope designed to be
implanted deep in ice in the South Pole. The system will measure and
chart the path of neutrinos, the smallest particles of matter, as they
pass from space through the earth.
Made up of 4,800 glass optical modules on 80 strings buried .8 to 1.5
miles below the ice, the IceCube telescope would effectively convert a
cubic kilometer of Antarctic ice into the world’s largest scientific
instrument.
The $15 million for UW-Madison was included in a fiscal year 2002
Veterans Administration-Housing and Urban Development appropriations
bill that also provides funding for the National Science Foundation.
The bill cleared a congressional conference committee today, Nov. 6,
and is expected to eventually win approval from the full U.S. House of
Representatives, Senate and President George Bush.
Expected to be completed over the next seven years, the $250 million
observatory will help physicists learn about the early formation of the
universe and the behavior of the most basic particles of matter. The
project involves both fundamental science and also science education
and outreach. Both the importance of the science and the excitement of
the location of the observatory capture the imagination of students of
all ages.
UW-Madison leads the international collaboration of 20 institutions,
which also includes UW-River Falls, and two historically black
institutions, Clark University of Atlanta and Southern University.
Neutrinos are invisible, uncharged, nearly massless particles that can
travel cosmological distances. Unlike the photons that make up visible
light, or other kinds of radiation, neutrinos can pass unhindered
through stars, vast magnetic fields and entire galaxies without
skipping a beat.
To be able to detect high-energy neutrinos and follow their trails back
to their points of origin promises unparalleled insight into such
extraordinary phenomena as colliding black holes, gamma-ray bursters,
the violent cores of distant galaxies and the wreckage of exploded stars.
IceCube would be one of the few scientific instruments to focus solely
on neutrinos, rather than more common photons. One of the others is
AMANDA, or Antarctic Muon and Neutrino Detector Array, a smaller, less
powerful South Pole system developed by UW-Madison and already in use.
Although AMANDA is 50 times smaller than IceCube, it was a successful
prototype that proved that the concept was viable.
Since neutrinos can and do skip through the Earth continuously, it is
logical to use the Earth to filter out other, confusing high-energy
events. The Earth between the telescope at the South Pole and the
northern sky filters out everything but neutrinos. Ice is a perfect
medium for their detection.
The glass modules at the heart of IceCube work like light bulbs in
reverse, creating electrical signals from the faint and fleeting
streaks of light created when the occasional neutrino crashes head on
into another particle such as a proton. The subatomic wreck creates
a muon, another subatomic particle that, conveniently, traces an
ephemeral trail of blue light through the ice identical to the path
of the neutrino. In theory, that trail can be used to point back to
the neutrino’s point of origin. The discovery of point sources of
high-energy cosmic neutrinos is a long-standing quest of modern
astrophysics.
U.S. Rep. David Obey, D-Wis., Sen. Herb Kohl, D-Wis., and Rep. Tammy
Baldwin, D-Wis., were instrumental in gaining support for the project
at a time when new science funding has been difficult to obtain. The
project has been approved by the National Science Board and peer
reviewed many times.
In FY 2000, NSF funded 333 grants worth $47.1 million to UW-Madison.
NSF is the second-largest single source of federal funding for
UW-Madison research programs, after the National Institutes of Health.
In FY 2000, UW-Madison was the second-largest recipient of NSF funding
in the Big Ten, the sixth-largest among universities, and the ninth-
largest overall.
IMAGE CAPTION: [http://www.news.wisc.edu/misc/icecube.html]
‘IceCube’ Neutrino Detector Array
Buried a mile deep in the Antarctic ice, the IceCube Neutrino Detector
Array promises a new kind of astronomy. When completed, IceCube will
occupy a cubic kilometer of deep ice, transforming the polar ice cap into
a detector capable of sampling the high-energy neutrinos that emanate
from some of the most distant and violent phenomena in the cosmos —
colliding black holes, galaxies with super violent cores and mysterious
gamma ray bursts. Like ghostly messengers, high-energy neutrinos traverse
huge distances, passing through stars, planets, magnetic fields and
entire galaxies without skipping a beat.