A. Zepeda

Space Program KOSMOTEPETL (project KLYPVE and TUS) for the study of extremely high energy cosmic rays

The scientific goal of the KOSMOTEPETL program is to observe and to study ultra high energy cosmic rays through the fluorescent tracks that they produce in the Earth atmosphere with the help of satellite based optical cameras based on the technology of a large mirror-concentrator of light. At low orbits (400–600 km) a mirror with an area of 400 m2 will allow us to observe neutrino induced horizontal tracks starting at the energy threshold of 1 EeV. With these neutrinos, which have to be produced in collisions of extreme energy cosmic rays (with energy >50 EeV) with background photons at distances >100 Mpc, the most distant cosmic ray sources will be revealed. Design of the TUS and KLYPVE detectors (the first detectors of the KOSMOTEPETL program with a mirror area 2 and 10 m2) is presented.

KLYPVE/TUS space experiments for study of ultrahigh-energy cosmic rays

The KLYPVE space experiment has been proposed to study the energy spectrum, composition, and arrival direction of ultrahigh-energy cosmic rays (UHECR) by detecting from satellites the atmosphere fluorescence and scattered Cherenkov light produced by EAS, initiated by UHECR particles. The TUS setup is a prototype KLYPVE instrument. The aim of the TUS experiment is to detect dozens of UHECR events in the energy region of the GZK cutoff, to measure the light background, to test the atmosphere control methods, and to study stability of the optical materials, PMTs, and other instrumental parts in space environment.

Electronics for the KLYPVE Detector

The KLYPVE optical detector on board the Russian segment of the ISS will observe 10 thousand km2 of the Earth atmosphere registering the extremely high energy cosmic ray (EHECR) particles producing fluorescent tracks in the atmosphere. In this article the design of the detector is presented, including: the Fresnel type mirror of 10 m2 area, the PMT retina of 2500 pixels, the pixel electronics, the data acquisition electronics, and the trigger system. The detector design is suited to conditions of the space experiment (wide range of temperature, short day-night cycle etc). The problem of selection of rare EHECR events in the presence of high intensity background light is discussed.

PREPARATION OF THE TUS SPACE EXPERIMENT FOR UHECR STUDY

We report on the current status of the TUS space mission project: its goals and the progress achieved so far. The Fresnel mirrors design, performed checks and their production are discussed. Also we discuss our future plans including auxiliary analysis of the fluorescence light yield measured this year by LAPP (Annecy), JINR (Dubna) and LIP (Lisbon) MACFLY Collaboration.

Cerro La Negra EAS Cherenkov array

The design of the air Cherenkov detector array for the Cerro La Negra site (elevation 4300 m asl) is presented. The most important features of the array are: autonomous operation of the detectors, low power electronics, laser communication lines and power supplied by solar panels and batteries. The joint operation of the array with water Cherenkov extensive air shower (EAS) particle detectors will allow to obtain information on EAS core positions, primary energies, arrival directions of the primary particles, and temporal profiles of the EAS pulses in air Cherenkov and particle detectors. The study of the EAS development above the shower maximum is among the main goals of this experiment.

Surface detector array for the Pierre Auger observatory

The Pierre Auger international collaboration will install two observatories, one in the southern hemisphere and other in the northern hemisphere. Each observatory will consist of two different subsystem: a surface detector array of about 1600 water Cherenkov detectors (WCD) and a set of fluorescence eyes to measure the longitudinal development of air showers. The large area covered by the surface detectors requires efficient calibration and monitoring methods that can be implemented remotely. We present several complementary methods to calibrate and monitor the performance of the individual surface detector stations. We also present some results of the studies made with a full size prototype tank in Puebla, Mexico and in Malargue, Argentina.