The Calibration System of the HAWC Gamma-Ray Observatory

Understand

The HAWC collaboration has recently completed the construction of a gamma-ray observatory at an altitude of 4100 meters on the slope of the Sierra Negra volcano in the state of Puebla, Mexico.

• In order to achieve an optimal angular resolution, energy reconstruction, and cosmic-ray background suppression for the air showers observed by HAWC, it is crucial to obtain good timing and charge calibrations of the photosensors in the detector.
• The HAWC calibration is based on a laser system which is able to deliver short light pulses to all the tanks in the array.
• The light intensity can range over 7 orders of magnitude, broad enough to cover all the dynamic range of the PMT readout electronics.