Justus Zorn Karlsruhe

A PMT test stand for the Pierre Auger Observatory(pdf)

Measuring the emitted fluorescence light from air showers allows the reconstruction of primary particle characteristics with a very high accuracy. The fluorescence detectors (FD) at the Pierre Auger Observatory in Argentina are therefore high quality air shower detectors but limited through statistics because of their low duty cycle of 15 %. This is due to the high sensitivity of the used photomultiplier tubes (PMT). In order to reach more statistics, especially in the range of ultra-high energy cosmic rays (higher than ??? eV), the PMTs could be operated at a lower high voltage during higher background conditions. To analyze and compare the performance of the PMTs used at the Pierre Auger Observatory under current and new working conditions (i.e. lower high voltages and higher background light), a PMT test stand is currently being developed. In this talk, the components of the test stand are introduced and first results characterizing PMTs are presented.