The HAWC Observatory is a TeV gamma-ray air-shower detector at the foot of the Pico de Orizaba mountain in Sierra Negra, Mexico. The HAWC Detector consists of a densely packed array of 300 water tank Cherenkov detectors covering an area of about 22,000 square meters. Credit: HAWC Collaboration
The HAWC Observatory is a next-generation gamma-ray detector located at an altitude of 4,100 meters on the slope of the dormant volcano Pico de Orizaba in Mexico. Credit: HAWC/NSF
The site of the HAWC water tanks is fully leveled and ready for tank construction. Construction of HAWC tanks and electronics installation began in May of 2012. Credit: Mike DuVernois, HAWC Collaboration
Each of the tanks is 7.3m in diameter and 4.5m high and holds four photomultiplier tubes each. HAWC records particles from air showers created when cosmic rays interact in the upper atmosphere. As shower particles pass through the water tanks, they create Cherenkov light, which will be recorded by sensitive photomultiplier tubes. Credit: HAWC Collaboration
In June 2011, a test array of seven tanks called VAMOS (Verification and Monitoring of Systems) began performing measurements of cosmic ray rates. Between June 2011 and March 2012, 3.2 billion air shower candidates were observed. Credit: Jordan Goodman, HAWC Collaboration
After the tanks are constructed they are all lined, instrumented, filled with water, and then covered with tarps. Credit: Zig Hampel-Arias, HAWC Collaboration
The HAWC construction crew gathers around the 300th and final Cherenkov tank in December of 2014. Credit: HAWC Collaboration
