Coherent radio emission from cosmic ray air showers computed by Monte-Carlo simulation with SElFAS

Abstract

We present here the first results of SElFAS (Simulation of Electric Field emitted by Air Shower), a new Monte-Carlo simulation of the radio emission by cosmic ray extensive air shower. The simulation is based on the complete geometrical description of secondary electrons and positrons created in air showers generated by protons above 10 PeV. The energy, position and angular distributions of secondary particles are extracted from CORSIKA simulations [1]. The electric field is then computed for each secondary particle during its travel in the atmosphere using the well-known equation of a moving charge which undergoes an acceleration. The total signal emitted by the air shower is per consequent the superposition of all particles contributions and it is computable for any ground position. We present the results obtained for the east–west and north–south polarizations of the total electric field. These polarizations are usually measured by radio detectors such as CODALEMA, LOPES, RAuger and AERA (Auger Engineering Radio Array). The characteristics and the comprehension of the radio emission of cosmic ray extensive air shower are crucial for the development of large radio detectors array.