CALIBRATION OF THE IBM DETECTOR

The TMB detector (named after its founding institutions: University of California, Irvine, the University of Michigan and Brookhaven Nationa l Laboratory) collected data on a wide range of phenomena for over eig ht years. It was the first and the largest of the ring imaging water C herenkov detectors. The detector consisted of 8000 metric tons of ultr a-pure water instrumented with 2048 photomultiplier tubes (PMTs). The PMTs were placed on the roof, floor, and walls of the detector in a la ttice of approximately 1 m spacing. It made measurements of contained events that ranged in energy from 15 MeV up to 1.5 GeV. This paper des cribes the calibration of the IMB detector. This procedure was accurat e and stable over a wide range of physical variables. It was used with little change throughout the entire eight-year lifetime of the experi ment. The IMB calibration is a model for future large-scale detectors that employ the water Cherenkov technique.