The front-end electronics for the Pierre Auger Observatory surface array

The Pierre Auger Observatory will study ultrahigh-energy cosmic rays, reaching full sensitivity for primaries with energies above 10/sup 19/ eV. The southern hemisphere site observatory is currently under construction. The surface array at this site will contain 1600 water Cherenkov detector stations distributed over 3000 km/sup 2/. In this paper, the front-end electronics of the surface detector stations, which couple analog signal processing with digital triggering, are described. The environmental constraints, history of the development, and the final design being deployed in the field are discussed. Performance characteristics of the electronics are presented.