AstrO: A portable cosmic ray telescope

This paper describes the design and performances of the AstrO (Astroparticle Outreach) cosmic muon telescope. The detector, contained in a trolley, is transportable and simple enough to be used by high-school students. The sophisticated data acquisition system is based on advanced DAQ technology and thanks to a simple interface is suitable for non-expert users. The detector is capable of measuring an integrated cosmic muon rate of 1–2 Hz with a precision (statistical and systematic) of a few percent in few hours of data taking. It can be used to detect variations induced by the solar activity, to determine the rate dependence on the geographical location (altitude and latitude) and to measure the cosmic muon rate attenuation due to surrounding high-density shielding such as rocks or concrete walls.