New measurements of cosmic ray air showers with the digital radio interferometer LOPES

Abstract

LOPES is a digital radio interferometer which measures the radio emission of extensive cosmic ray air showers. It mainly consists of 30 dipole antennas installed in co-location with KASCADE-Grande at the Karlsruhe Institute of Technology (KIT) in Germany. KASCADE-Grande measures the secondary air shower particles at ground. Whenever KASCADE-Grande detects a high-energy cosmic ray event (≳1016 eV), it triggers LOPES which then digitally records the radio signal in the frequency band from 40 to 80 MHz. Using interferometric methods, LOPES is able to successfully detect air shower induced radio pulses, even in the noisy environment at the KIT. In the present studies, a considerable progress in understanding the radio emission mechanism is shown: The latest version of the "radio emission in air shower" simulation program, REAS3, seems to be the first Monte Carlo tool which is able to reproduce the magnitude and slope of most of the measured lateral distributions. © Author(s) 2011.