February 4, 2005  


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.”

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 



The Stanford Linear Accelerator Center is managed by Stanford University for the US Department of Energy

Last update Friday February 04, 2005 by Emily Ball