The Gamma Ray Large Area Space Telescope:
Instrument Technology
Development (Overview)
Peter F. Michelson
for the GLAST Collaboration
Abstract
The Gamma Ray Large Area Telescope (GLAST) is a satellite-based experiment
under development to measure the cosmic gamma-ray flux in the energy range
from 20 MeV to 300 GeV.
The GLAST mission is a part of NASA's Office of Space Science strategic
plan with a scheduled new start in 2002.
The primary instrument for the mission is a pair-conversion telescope.
Our international collaboration is developing a telescope design which includes
a precision pair tracker/converter section utilizing silicon-strip detectors,
a CsI scintillating crystal calorimeter arranged in a hodoscopic configuration,
an anticoincidence shield that is an array of plastic scintillator tiles
read out with optical waveshifting fibers, and a powerful distributed data
acquisition and triggering system.
Central to the instrument design is the utilization of real-time multi-level
hardware and software triggers to discriminate against backgrounds and
efficiently recognize valid gamma-ray events over a wide field-of-view.
The trigger method is made possible, in part, by the self-triggering ability
of the silicon-strip detectors and the capabilities of the present generation
of space-qualified processors.
The design and expected performance of the telescope are presented.
Accompanying posters (A. Moiseev et al., W. N. Johnson et al.,
R. Johnson et al.) discuss details of each measurement subsystem and
present a summary of results from a high-energy beam test of prototypes.
The work described has been supported by both NASA and the Department of
Energy.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:19.