PMT and scintillator strip system testing and characterization for the BATATA detector: I

SANCHEZ, F.; SUPANITSKY, D.A.; MEDINA-TANCO, G.; PAIC, G.; D'OLIVO, J.C.; PATINO-SALAZAR, M.E.; GUZMAN, A.; CARMONA, J.M.; ALFARO-MOLINA, R.

Otro; Publicacion Interna Observatorio Pierre Auger (GAP-NOTE); 2008

Observatorio Pierre Auger

The BATATA detector has 49×6 adquisition channels (98 for each one of the three buried x-y planes). In- dividual channels operate in the following way. Charged particles propagating underground and depositing energy in a scintillator strip produce fluorescence light, a fraction of which, after multiple reflections inside the strip, gets into the wavelength shifter optical fiber (WLS), where part of it is absorbed and re-emitted in the appropriate solid angle for propagation. The optical fiber transports the light to its corresponding pixel of a photomultiplier tube (PMT). Fhe front-end (FE) electronic board applies the first level trigger (which is a pulse height threshold) and digitizes the signal coming from the PMT. Finally, the FE trasmits the signal in differential mode to surface where the second level trigger (SLT) is implemented on a FPGA. Before assembling the detector as a whole, every component must be tested in order to warrant its quality and characterize its response under laboratory conditions. This note is the first on a series in which we present the setups and results of the first of several tests that are-being/will-be performed on the phototubes and the systems of scintillators strips with their corresponding optical fibers glued into them. The testing procedure of individual optical fibers and the gluing protocol, are described elsewhere.