Radio detection of cosmic rays with LOPES

Grupen, C.; Asch, T.; Badea, A. F.; Bahren, L.; Bekk, K.; Bercuci, A.; Bertaina, Mario Edoardo; Biermann, P. L.; Blumer, J.; Bozdog, H.; Brancus, I. M.; Buitink, S.; Bruggemann, M.; Buchholz, P.; Butcher, H.; Chiavassa, Andrea; Cossavella, F.; Daumiller, K.; Di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Haungs, A.; Heck, D.; Horandel, J. R.; Horneffer, A.; Huege, T.; Kampert, K. H.; Kolotaev, Y.; Kromer, O.; Kuijpers, J.; Lafebre, S.; Mathes, H. J.; Mayer, H. J.; Meurer, C.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, Gianni Maria; Nehls, S.; Nigl, A.; Obenland, R.; Oehlschlager, J.; Ostapchenko, S.; Over, S.; Petcu, M.; Petrovic, J.; Pierog, T.; Plewnia, S.; Rebel, H.; Risse, A.; Roth, M.; Schieler, H.; Sima, O.; Singh, K.; Stumpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; van Buren, J.; Walkowiak, W.; Weindl, A.; Wochele, J.; Zabierowski, J.; Zensus, J. A.; Zimmermann, D.

Data taken with a radio antenna array in combination with the ground-level air shower experiment KASCADE-Grande at the Forschungszentrum Karlsruhe open up the possibility to measure large extensive air showers with this new technique. The pulse height of the observed radio signals scales with the primary energy of the particles initiating the air shower. The dependence of the radio signal on the angle of the shower axis with respect to the Earth's geomagnetic field and the coherence of the radiation suggest that the radio signal generation is due to the geosynchrotron mechanism.