30TH INTERNATIONAL COSMIC RAY CONFERENCE Operation of LOPES-30 for Polarization Measurements of the Radio Emission of Cosmic Ray Air Showers

The LOPES-30 experiment, located at the site of the air shower experiment KASCADEGrande at Forschungszentrum Karlsruhe, Germany, is an array of 30 dipole antennas set-up to investigate the pulsed radio emission from cosmic ray air showers in the Earth’s atmosphere. After one year of measurements of the East-West polarization by all 30 antennas, recently, the LOPES-30 set-up was reconfigured to perform dual-polarization measurements. Half of the antennas have been configured for measurements of the North-South polarization direction. By measuring at the same time both, the E-W and N-S polarization components of the radio emission, the geosynchrotron effect as the dominant emission mechanism in air showers can be verified. The status of the measurements, including the absolute calibration procedure of the antennas as well as a preliminary analysis of dual-polarized event examples are reported.