Multi-scale and multi-frequency studies of cosmic ray air shower radio signals at the CODALEMA site

Richard Dallier (1, 2) , J.L. Béney (1) , H. Carduner (1) , Didier Charrier (1) , L. Denis (2) , F. Gaté (1) , A. Lecacheux (3) , V. Marin (1) , Lilian Martin (1, 2) , Benoît Revenu (1) , D. Torres Machado (4, 1)

1 SUBATECH - Laboratoire SUBATECH Nantes
2 USN - Unité Scientifique de la Station de Nançay
3 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
4 UFRJ - Universidade Federal do Rio de Janeiro [Brasil] = Federal University of Rio de Janeiro [Brazil] = Université fédérale de Rio de Janeiro [Brésil]

Since 2003, the Nançay Radio Observatory hosts the CODALEMA experiment, dedicated to the radio detection of cosmic ray induced extensive air showers. After several instrumental upgrades, CODALEMA is now composed of: - 57 self-triggering radio detection stations working in the [20-200] MHz band, over 1 km2; - an array of 13 scintillators acting as a particle detector; - a compact array of 10 cabled antennas, triggered by the particle detector, to test the capabilities of a phased antenna cluster to cleverly select air shower events. In addition, CODALEMA supports the EXTASIS project, aiming at detecting the expected lowfrequency signal produced by the sudden deceleration of the air shower particles hitting the ground. Beside these dedicated arrays, the Nançay site will host the NenuFAR radio telescope (recognized as a SKA pathfinder), made of 1824 dual crossed-polarization antennas similar to the CODALEMA ones. All these arrays present different antenna density and extent, and could be operated in a joint mode to record simultaneously the radio signal coming from an air shower. Therefore, the upgraded CODALEMA facilities could offer a complete description of the air shower induced electric field at small, medium and large scale, and over an unique and very wide frequency band (from ~ 2 to ~ 200 MHz). The use of multi-band detectors combined with composite trigger algorithms could help boosting the radio detection technique as a candidate for an accurate composition measurement with a high efficiency, or in the frame of a further very large cosmic ray observatory. We describe the current and foreseen instrumental set-up together with the prospective developments of the radio detection technique.

Mots clés: Codalema; Radiodetection of cosmic ray air showers

Domaines: Astrophysique [astro-ph]

Richard Dallier, J.L. Béney, H. Carduner, Didier Charrier, L. Denis, et al.. Multi-scale and multi-frequency studies of cosmic ray air shower radio signals at the CODALEMA site. 34th ICRC, The Hague, Netherlands, Jul 2015, The Hague, Netherlands. ⟨hal-01164680⟩