Fermi's LAT Instrument

Fermi's Large Area Telescope (LAT) detects particles produced in a physical process known as pair production that epitomizes Einstein's famous equation, E=mc2. When a gamma ray, which is pure energy (E), slams into a layer of tungsten in one of the tracking towers that compose the LAT, it creates mass (m) in the form of a pair of subatomic particles, an electron and its antimatter counterpart, a positron. Several layers of high-precision silicon detectors track the particles as they move through the instrument. The direction of the incoming gamma ray is determined by projecting the particle paths backward. The particles travel through the trackers until they reach a separate detector called a calorimeter, which absorbs and measures their energies. The LAT produces gamma-ray images of astronomical objects, while also determining the energy of each detected gamma ray.



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Animation Credits

Chris Meaney (HTSI): Lead Animator
Steven Ritz (NASA/GSFC): Scientist
Please give credit for this item to:
NASA's Goddard Space Flight Center Conceptual Image Lab

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Fermi Gamma-ray Space Telescope

Data Used:
Fermi/LAT None
Fermi None

This item is part of these series:
GLAST Pre-Launch
Astrophysics Animations

Goddard TV Tape:
G2007-011HD -- GLAST Pre-Launch Resource Tape

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