ON POLARIZATION OF COHERENT RADIO SIGNALS FROM EAS

The influence of the geomagnetic field on EAS radio emission is analysed by simulating with a three-dimensional Monte Carlo the development of an e.m. cascade in the earth's magnetic field taking full account of Coulomb scattering. We compute for vertical showers at various heights the dipole moment M, the transverse current J, together with the negative charge excess e{open}. A discussion of the radiation field shows that the geomagnetic effect is appreciably less than previously esti mated and depends on frequency. The polarization of the observed signal decreases markedly with increasing frequency, which seems to agree with experimental data. © 1969 Società Italiana di Fisica.