Geomagnetic effects observed by the Codalema experiment

Lilian Martin (1, 2, 3) , Collaboration Codalema

1 SUBATECH - Laboratoire SUBATECH Nantes
2 USN - Unité Scientifique de la Station de Nançay
3 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace

The CODALEMA experiment is measuring transient radio emissions associated to extended air showers produced by high energy cosmic rays. The experimental setup installed at the Nancay Radio Observatory in France has recently undergone hardware upgrades and an extension of the surfaces covered by both the antenna and the scintillator detector arrays. The experimental data allow to investigate the main features of these radio signals and the underlying electric field production mechanisms. Some of the latest experimental results of CODALEMA are presented. They have been analyzed assuming a linear dependence of the electric field with respect to v ^ B. Within the CODALEMA observation conditions at Nancay, the detection eficiency, the arrival direction distribution and the polarity of the radio signals can be interpreted in terms of a geomagnetic effect. A R&D effort is currently underway to develop the hardware elements for the deployment of a large detector array based on active antennas. The main features of the first prototype of the CODALEMA autonomous station are briefly described.

Mots clés: CODALEMA; Radio detection; Ultra high energy cosmic rays; Extensive air showers

Domaines: Phénomènes cosmiques de haute energie [astro-ph.HE]; Phénomènes cosmiques de haute energie [astro-ph.HE]

Lilian Martin, Collaboration Codalema. Geomagnetic effects observed by the Codalema experiment. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2011, 630 (1), pp.177-182. ⟨10.1016/j.nima.2010.06.059⟩. ⟨hal-00438151⟩