Development of an atmospheric Cherenkov imaging camera for the CANGAROO-III experiment

A Cherenkov imaging camera for the CANGAROO-III experiment has been developed for observations of gamma-ray induced air-showers at energies from 10${}^{11}$ to 10${}^{14}$ eV. The camera consists of 427 pixels, arranged in a hexagonal shape at 0.17${}^{\circ }$ intervals, each of which is a 3/4-inch diameter photomultiplier module with a Winston-cone–shaped light guide. The camera was designed to have a large dynamic range of signal linearity, a wider field of view, and an improvement in photon collection efficiency compared with the CANGAROO-II camera. The camera, and a number of the calibration experiments made to test its performance, are described in detail in this paper.