Séminaire Doctoral / Seminar PhD |
| « Missing energy in the radio-emission of particle cascades » |
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Simon Chiche |
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In this talk I will mainly give a more complete overview of the topic I presented
at the PhD day so the abstract is the same! What is the origin of ultra-high energy cosmic-rays, these charged atomic nuclei that arrive on Earth with energy > 10^18 eV? To collect enough particles and solve this mystery, observatories covering gigantic surfaces have to be built, using efficient detection techniques. Radio detection, i.e., the detection of radio signals from the particle cascades (air-showers) that ultra-high energy particles induce in the atmosphere, is a robust, efficient, scalable and hence promising technique. Cascades induced by particles with inclined arrival directions are of particular interest as they exhibit a large footprint that allows to sample the signal with only few antennas. The construction of several of such large-scale radio-detectors focusing on inclined air-showers are being currently planned (GRAND, BEACON, GCOS). However, the physics of the radio emission of very inclined air-showers is scarcely understood, and needs to be explored with analytical and numerical methods. In the preparation for these large-scale radio-experiments I have developed an innovative fast semi-analytical simulation tool for very inclined air-showers. This tool relies on a deep understanding on the radio signal polarisation and enabled us to identify a new radio emission signature, specific for inclined air-showers, in a new regime that was not described by any model. The understanding of this regime would be a major advancement toward this new era of large-scale UHE astroparticle detection. |
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vendredi 29 avril 2022 - 16:00 Salle Entresol Daniel Chalonge, Institut d'Astrophysique |
| Page web du séminaire / Seminar's webpage |