ON THE OPTIMIZATION OF MULTICHANNEL CAMERAS FOR IMAGING ATMOSPHERIC CHERENKOV TELESCOPES

The optimization of the pixel size and of the field of view of the mul tichannel cameras of imaging atmospheric Cherenkov gamma-ray telescope s is discussed using the minimum distortion of the Cherenkov light ima ges as a basic criterion. The parameters defining the shape of the Che renkov image in the second-moment approach can already be properly det ermined using a pixel size similar or equal to 0.25 degrees. The orien tation of the image is more sensitive to the pixel size; thus, the opt imal determination of orientation parameters requires a reduction of t he pixel size to similar or equal to: 0.15 degrees. For observations o f point gamma-ray sources the field of view of the imaging camera shou ld not be significantly less than 4 degrees. To study moderately exten ded sources and sources whose positions are only known within similar or equal to: 1 degrees (like many EGRET gamma-ray sources) a camera wi th field of view greater than or equal to 5 degrees is required.