The absolute, relative and multi-wavelength calibration of the Pierre Auger Observatory fluorescence detectors

R. KNAPIK, BAULEO, BECKER, BRACK, CARUSO, DELLE FRATTE, DOROFEEV, HARTON, ISOLIA, MATTHEWS, MENSHIKOV, ORTOLANI, PETRINCA, PICHEL, RIGGI, ROBERTS, J. RODRIGUEZ, A.C. ROVERO, SCUDERI, TAMASHIRO, TORRESI, TUCI, WIENCKE

Merida, Yucatan, Mexico

Conferencia; 30th International Cosmic Ray Conference; 2007

Absolute calibration of the Pierre Auger Observatory fluorescence detectors uses a 375 nm light source at the telescope aperture. This end-to-end technique accounts for the combined effects of all detector components in a single measurement. The relative response has been measured at wavelengths of 320, 337, 355, 380 and 405 nm, defining a spectral response curve which has been normalized to the absolute calibration. Before and after each night of data taking a relative calibration of the phototubes is performed. This relative calibration is used to track both short and long term changes in the detector’s response. A cross check of the calibration in some phototubes is performed using an independent laser technique. Overall uncertainties, current results and future plans are discussed.