Groundbreaking for Cosmic Ray Project

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