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Aug. 26, 2004 – A groundbreaking ceremony
will be held 9 a.m. Saturday Aug. 28 in the desert southwest of
Delta, Utah, for the Telescope Array – a Japanese and American
cosmic ray observatory designed to find the source of the most
energetic particles in the universe.
“This is the first step towards implementation of an $18
million cosmic ray project to resolve the puzzling mysteries of
the highest-energy cosmic rays,” says Kai Martens, an assistant
professor of physics at the University of Utah.
Pierre Sokolsky, the university’s physics chairman, says
previous research in Japan and the United States – including
the university’s High-Resolution Fly’s Eye observatory
at Dugway Proving Ground – “uncovered a mystery with
regard to the highest-energy cosmic ray particles.”
“We don’t know where they are coming from,”
Sokolsky says. “We don’t know why they are here. This
groundbreaking is a guarantee there will be tremendous new data
to shed light on this mystery.”
The groundbreaking ceremony atop Black Rock Mesa in Millard County
is for the first of three “fluorescence detectors”
to be built on hilltops. The other two will be built later on
Long Ridge and between the Drum and Little Drum Mountains.
Each of the three fluorescence detectors will consist of a building
with garage-type doors that open to reveal 12 sets of mirrors,
each consisting of 16 segments. The mirrors will detect faint
blue flashes in the night sky caused when cosmic rays hit atmospheric
gas molecules.
In addition to the three hilltop fluorescence detectors, the Telescope
Array also will include a “ground array” of 576 scintillation
detectors sitting on 2-foot-tall steel tables that will be scattered
in a vast grid on a roughly 18-by-22-mile area west of Delta,
Hinckley and Deseret. The scintillation detectors will measure
“air showers” of subatomic particles that reach the
ground after cosmic rays hit gas molecules in the atmosphere.
The Japanese government last year approved $12 million to build
the three fluorescence detectors and 576 scintillation detectors.
The University of Utah and other U.S. universities are seeking
$6 million in federal funds to either enhance the three fluorescence
detectors built with Japanese funds or, if necessary, add a new
one.
Construction to Take Two Years
The University of Utah is leasing the first three fluorescence
detector sites, including Black Rock Mesa, from Utah’s School
and Institutional Trust Lands Administration (SITLA), which has
approved the project, Sokolsky says.
The gravel road to the site was recently improved, and a contractor
started pouring the foundation for the Black Rock Mesa fluorescence
detector on Wednesday Aug. 25. Sokolsky said the building should
be done by the end of November, and construction of the second
and third fluorescence detectors will begin in spring 2005.
The Japanese and American research team is now in the process
of seeking U.S. Bureau of Land Management approval for most of
the ground array of scintillation detectors, and SITLA approval
for 18 of the detectors located on state land, Martens says. Scientists
hope to start installing those 18 detectors for test purposes
this winter.
Sokolsky says cash flow will determine how quickly the sprawling
observatory is completed, but he expects it will be finished in
two years, and “in three years, data will start coming out
of this experiment.”
The Telescope Array is a collaboration by several U.S. and Japanese
universities, led by the University of Utah and the University
of Tokyo’s Institute for Cosmic Ray Research.
Directions to the Groundbreaking at Black Rock Mesa
From Delta, Utah, proceed west on U.S. 6/50.
Roughly 4 miles from Delta, turn south (left) onto S.R. 257 toward
Milford.
Proceed roughly 11 miles south on S.R. 257, then turn west (right)
onto a gravel road which proceeds along the south edge of Black
Rock Mesa. The turnoff is located where S.R. 257 comes closest
to Black Rock Mesa.
Follow the gravel road. After about one-half mile, the road will
cut through the face of the mesa and proceed to the top. Once
atop the mesa, follow the road about a mile to the groundbreaking
site.
Background on Cosmic Ray Research
The Telescope Array is distinct from the University of Utah’s
existing $14.4 million High-Resolution Fly’s Eye cosmic
ray observatory at Dugway Proving Ground, and the $50 million
Pierre Auger Project, another kind of cosmic ray observatory proposed
for construction in Millard County or elsewhere.
All three projects seek to understand a major puzzle: What incredibly
powerful phenomenon in the universe is hurling ultrahigh-energy
cosmic rays through space?
Cosmic rays, discovered in 1912, are subatomic particles: the
nuclei of atoms such as hydrogen, oxygen, carbon, nitrogen or
iron. Medium-energy cosmic rays come from exploding stars, while
the sun and other stars emit even lower-energy cosmic rays.
But the source of ultrahigh-energy cosmic rays is unexplained.
They are 100 million times more energetic than anything produced
by particle smashers on Earth. Scientists theorize they may come
from noisy radio galaxies, supermassive black holes at the centers
of active galaxies, shock waves from colliding galaxies, bizarre
sources such as so-called cosmic strings or even from the decay
of massive particles left over from the “big bang”
that scientists believe formed the universe about 13 billion years
ago.
The University of Utah is a pioneer in cosmic ray research. After
atmospheric humidity stymied a 1950s effort to observe cosmic
rays from upstate New York, University of Utah physicists built
a prototype in New Mexico in 1976, constructed the Fly’s
Eye at Dugway Proving Ground during 1980-1981, improved it in
1986, and then upgraded it during 1994-1999 and renamed it the
High-Resolution Fly’s Eye. The name comes from the use of
fly-like multifaceted mirrors to observe the sky.
The highest-energy cosmic ray ever detected was measured in 1991
by the Fly’s Eye. It had an energy of 300 billion billion
electron volts (billion twice is correct). That single subatomic
particle carried as much energy as a fast-pitched baseball.
But the High-Resolution Fly’s Eye and Japan’s AGASA
cosmic ray observatory have learned as much as they can, so a
new observatory is needed.
A January 2004 news release outlining the Telescope Array project
in greater detail is available at:
http://www.utah.edu/unews/releases/04/jan/cosmic.html
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