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First GLAST Tracker Arrives at SLAC
By
Matthew Early Wright
The Gamma Ray Large Area Telescope (GLAST) satellite project celebrated
a milestone last month with the arrival of the first tracker module at
SLAC.
Built in Italy at the
Istituto Nazionale di Fisica Nucleare (INFN), the tracker weathered the
journey easily, and is performing well in tests. It is one of 16 such
modules that constitute the main array of the satellite. GLAST will
eventually help address many of the major unanswered questions in
astrophysics, particle physics and cosmology.
“This is an extraordinarily complex instrument to design and build,”
said Persis Drell (RD), deputy project manager with responsibility for
the tracker. “It has to withstand the rigors of launch and the
environment of space, and we’ve met and exceeded those challenges.”
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Pictured left to
right: Luca Baldini (INFN, Pisa) and Robert Johnson (UCSC). (Photo by
Diana Rogers) |
Drell applauded the efforts of Ronaldo Bellazzini (INFN) and his team
for contributing much of the mechanical design and assembly, Robert
Johnson (UC Santa Cruz), who designed and built the electronic
components, and the engineering team here at SLAC led by Dave Rich and
Martin Nordby (both REG). Drell added that the arrival of the tracker is
a huge achievement for the team, and a significant advancement for the
entire project.
The GLAST satellite will be capable of gathering data that, until now,
has all but eluded astrophysicists and cosmologists. By collecting and
imaging gamma radiation, it will help researchers visualize all sorts of
mysterious phenomena, from black hole accretions to gamma ray bursts, in
remarkable detail.
“It is very much a telescope, and in space it will behave like a
telescope, even though it looks like a particle physics detector,”
Johnson said. The similarity is more than just superficial, as it may
also help to address one of the biggest questions in modern particle
physics. Collisions of supersymmetric particles—the type believed to
constitute dark matter—are thought to release large amounts of gamma
radiation, which GLAST should be able to capture.
“We know there’s a lot of dark matter out there, but nobody knows what
it is,” Johnson said. But Scientists are very close to learning a whole
lot more about this strange, invisible stuff. At around the same time
GLAST is scheduled to launch in 2007, the Large Hadron Collider (LHC)
should begin operation at CERN. In what could prove to be a one-two
punch, the LHC will attempt to create supersymmetric particles here on
earth, while GLAST will look for evidence of supersymmetric collisions
in space.
The first tracker is currently performing at 98.7 percent efficiency in
tests. “We plugged it in, and it just worked. It was extremely
gratifying,” according to Drell. The engineering team is scheduled to
mate the tracker to its companion calorimeter module next month, after
which it will be installed onto the grid array.
The second tracker module is currently being tested in a thermal vacuum
chamber by INFN in Rome. On track to be shipped to SLAC in just two
weeks, it is already giving the team reason for optimism. “It’s actually
doing better than the first, testing at over 99 percent efficiency,”
Johnson said.
For more information, see:
http://www-glast.stanford.edu
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