LOW ENERGY γ-RAY DETECTION (E ≤ 30 GEV): EFFECT OF EARTH'S MAGNETIC FIELD AND A NOVEL TRIGGER TECHNIQUE

Here we discuss two related aspects of the detection of low energy gammas by IACT's (Imaging Atmospheric Cherenkov Telescope): the effect of the Earth's magnetic field and a possible novel trigger technique. The Earth's magnetic field affects the development of extensive air showers (EAS), spreading the collected photons and, therefore, decreasing the sensitivity of the Cherenkov telescope. The new effects that appear in low energy showers can be partially offset modifying the trigger criteria. The result is a large collection area (> 1000 m2) below 10 GeV for a typical 17 m class telescope, increasing its sensitivity at these energies.