L. Martin

High-precision measurements of extensive air showers with the SKA

As of 2023, the Square Kilometre Array will constitute the worlds largest radio telescope, offering unprecedented capabilities for a diverse science programme in radio astronomy. At the same time, the SKA will be ideally suited to detect extensive air showers initiated by cosmic rays in the Earths atmosphere via their radio emission. With its very dense and uniform antenna spacing in a fiducial area of one km 2 and its large bandwidth of 50-350 MHz, the low-frequency part of the SKA will provide very precise measurements of individual cosmic ray air showers. These precision measurements will allow detailed studies of the mass composition of cosmic rays in the energy region of transition from a Galactic to an extragalactic origin. Also, the SKA will facilitate three-dimensional tomography of the electromagnetic cascades of air showers, allowing the study of particle interactions at energies beyond the reach of the LHC. Finally, studies of possible connections between air showers and lightning initiation can be taken to a new level with the SKA. We discuss the science potential of air shower detection with the SKA and report on the technical requirements and project status.

Precision measurements of cosmic ray air showers with the SKA

Supplemented with suitable buffering techniques, the low-frequency part of the SKA can be used as an ultra-precise detector for cosmic-ray air showers at very high energies. This would enable a wealth of scientific applications: the physics of the transition from Galactic to extragalactic cosmic rays could be probed with very high precision mass measurements, hadronic interactions could be studied up to energies well beyond the reach of man-made particle accelerators, air shower tomography could be performed with very high spatial resolution exploiting the large instantaneous bandwidth and very uniform instantaneous

Ultimate precision in cosmic-ray radio detection — the SKA

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Main features of cosmic ray induced air showers measured by the CODALEMA experiment

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Near-field radio emission induced by extensive air showers

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Computing the electric field from Extensive Air Showers using a realistic description of the atmosphere

coverage of SKA1-LOW, and the physics of thunderstorms and possible connections between cosmic rays and lightning initiation could be studied in unprecedented levels of detail. In this article, we describe the potential of the SKA as an air shower radio detector from the perspective of existing radio detection efforts and discuss the associated technical requirements.

Low frequency observations of cosmic ray air shower radio emission by CODALEMA/EXTASIS

As of 2023, the low-frequency part of the Square Kilometre Array will go online in Australia. It will constitute the largest and most powerful low-frequency radio-astronomical observatory to date, and will facilitate a rich science programme in astronomy and astrophysics. With modest engineering changes, it will also be able to measure cosmic rays via the radio emission from extensive air showers. The extreme antenna density and the homogeneous coverage provided by more than 60,000 antennas within an area of one km2 will push radio detection of cosmic rays in the energy range around 1017 eV to ultimate precision, with superior capabilities in the reconstruction of arrival direction, energy, and an expected depth-of-shower-maximum resolution of < 10 g/cm2.

The CODALEMA/EXTASIS experiment: a multi-scale and multi-wavelength instrument for radio-detection of extensive air-showers

The radio signals produced by extensive air showers initiated in the atmosphere by high energy cosmic rays are routinely observed and registered by the various instruments of the CODALEMA experiment located at the Nancay radio observatory and notably by the large array of self-triggering stations equipped with wide band and dual polarization antennas. Precise comparisons between observed radio signals and simulations performed with the SELFAS code allow most of the main features of the primary cosmic ray to be determined: arrival direction, energy and

Direct measurement of the vertical component of the electric field from EAS

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

estimates from which a the composition in the energy range covered by CODALEMA may be derived. After a presentation of the analysis methods, its sensitivity will be discussed and the results obtained over a significant set of experimental events will be detailed.