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Compton Gamma-Ray Observatory Science Support Center

The Energetic Gamma Ray Experiment Telescope (EGRET)

The Energetic Gamma Ray Experiment Telescope (EGRET)

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The Energetic Gamma Ray Experiment Telescope (EGRET) provides the highest energy gamma-ray window for the Compton Observatory. Its energy range is from 20 million electron volts (20 MeV) to 30 billion electron volts (30 GeV). EGRET is 10 to 20 times larger and more sensitive than previous detectors operating at these high energies and has made detailed observations of high-energy processes associated with diffuse gamma-ray emission, gamma-ray bursts, cosmic rays, pulsars, and active galaxies known as blazars.

The EGRET instrument produces images at these energies using high-voltage gas-filled spark chambers. High-energy gamma rays enter the chambers and produce an electron-positron pair of particles which cause sparks. The path of the particles is recorded allowing the determination of the direction of the original gamma ray. The particle energies are recorded by a NaI crystal beneath the spark chambers providing a measure of the original gamma-ray energy.

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This page was last modified on Monday, 01-Aug-2005 13:41:42 EDT.

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