The Performance Test of LHAASO-MD Photomultiplier

Exploring the origins of high-energy cosmic rays and related cosmic evolution, high-energy celestial movements, and new physical frontiers is the uppermost scientific objective of the large high altitude air shower observatory (LHAASO). The large-area moun detector (MD) immensely reduces the background of cosmic ray, which can greatly enhance the sensitivity of high-energy gamma ray detection. A photomultiplier tube (PMT), one of the vital components of the MD, is responsible for receiving Cherenkov electrons in the water and converting it into an electrical signal output, which can directly affect the performance of MD. The metrical results of 2% samples from Daocheng Lab show that the performance of PMT meets the requirements of MD, and the relative deviation from the batch test results is less than 2%.