Geomagnetic origin of the radio emission from cosmic ray induced air showers observed by CODALEMA

Understand

The new setup of the CODALEMA experiment installed at the Radio Observatory in Nancay, France, is described.

• It includes broadband active dipole antennas and an extended and upgraded particle detector array.
• The latter gives access to the air shower energy, allowing us to compute the efficiency of the radio array as a function of energy.
• We also observe a large asymmetry in counting rates between showers coming from the North and the South in spite of the symmetry of the detector.