GLAST Instruments

The Gamma-ray Large Area Space Telescope (GLAST) is an international and multi-agency space observatory that will study the cosmos in the photon energy range of 8,000 electronvolts (8 keV) to greater than 300 billion electronvolts (300 GeV). An electronvolt is a unit of energy close to that of visible light, so GLAST will catch photons with energies thousands to hundreds of billions of times greater than those we see with our eyes (1 keV = 1,000 eV, 1 MeV = 1,000,000 eV, 1 GeV = 1,000,000,000 eV).

GLAST carries two instruments: the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM). The LAT is GLAST's primary instrument, and the GBM is the complementary instrument.

The LAT has four subsystems that work together to detect gamma rays and to reject signals from the intense bombardment of cosmic rays. For every gamma ray that enters the LAT, it will have to filter out 100,000 to one million cosmic rays, charged particles that resemble the particles produced by gamma rays. The four main subsystems are:
- Tracker
- Calorimeter
- Anticoincidence Detector
- Data Acquisition System

With its very large field of view, the LAT sees about 20% of the sky at any given moment. In sky-survey mode, which is the primary observing mode, the LAT will cover the entire sky every three hours. The observatory can also be pointed at targets of opportunity, and can slew autonomously when either instrument detects sufficiently bright gamma-ray bursts (GRBs). The LAT is at least 30 times more sensitive than any previous gamma-ray instrument flown in space, and will detect thousands of new sources during GLAST's five-year primary mission.

The GBM consists of 12 detectors made of sodium iodide for catching X rays and low-energy gamma rays, and two detectors made of bismuth germanate for high-energy gamma rays. Together, they detect cover X rays and gamma rays in the energy range between 8 keV to 30 MeV, overlapping with the LAT's lower-energy limit. The GBM detectors will view the entire sky not occulted by Earth, and are expected to pick up about 200 GRBs per year, as well as solar flares and other transient events. The combination of the GBM and the LAT provides a powerful tool for studying GRBs over a very wide range of energies.

The launch of the United Launch Alliance Delta II rocket carrying NASA's GLAST spacecraft is now set for 11th June 2008.

Category:

Science & Technology

Tags:

• GLAST
• Instruments
• LAT
• GBM

[FarFromEquilibrium]

Earth and Moon have stronger gamma signals than the Sun.. wow . I would have never suspected that!

[BrunoTheQuestionable]

I suspect its because Nitrogen atoms are better at scattering gamma rays than protons are.

[mazdaplz]

Thank god computers are fast enough to draw this map now. I wonder what new instruments will be available next.

[NsaneNtheNbrane]

That is very impressive.

[studio7manga]

I wonder if antimatter could be harvested in a similar manner.

[mib2259]

Nice!