Beam Test at CERN

"Fine-tuning" the LAT. Constructed out of spare modules (i.e., two Trackers and three calorimeters), a "mini" LAT calibration unit was used in the Beam Test at CERN from the end of July through mid-September, 2006.

These tests were conducted in order to better understand the behavior of different particles as they strike the detector at different angles.

Results of these tests will be useful in validating Monte Carlo (MC) simulations used for ground tests of GLAST's Large Area Telescope (LAT) during its final integration and test phases. Results will also be used to tune aspects of the reconstruction process.
Beam testing was conducted at low energies (50MeV - 15GeV) using the Proton Synchrotron (PS) beam, and at high energies (10-300 GeV) using the Super Proton Synchrotron (SPS). Ultimately, these tests will help to better calibrate the Large Area Telescope (LAT) once it is launched into orbit.

Primary objectives included:

  • Characterizing performance at high energies (i.e., corrections for leakage, inter-tower gaps, backsplash, etc.)
  • Verifying MC simulations of the detector's response in terms of:
    • Electromagnetic showers (gamma, electron)
    • Point Spread Function and Energy reconstruction methods
    • Distributions of quantities related to those used in background rejection with hadron beams

Extracting information. A slightly "beefed up" (i.e., somewhat enhanced) version of the Glast Event Analysis Machine (GLEAM) was used to extract extra information about the beamline through the LAT. Tests also afforded opportunities for online monitoring of code, and testing the pipeline's ability to safely and reliably transfer large amounts of data at the speeds for which it was designed.

For detailed information about the tests visit the Beam Test 2006 wiki pages.