A particle detector array for high-resolution cosmic ray observations with the SKA radio telescope.

Cosmic rays are the most energetic particles in the Universe but their origin remains unknown. The VUB, together with international partners, is preparing a long-term observation project with the Australian site of the Square Kilometer Array (SKA), for which construction is now beginning. The SKA will provide very detailed information in the energy range where a transition from galactic to extragalactic sources is expected. The observations will provide new insights into the highest energy Galactic sources. Whereas dedicated cosmic-ray observatories usually require large collaborations and running costs, observations with radio telescopes only require a one-time investment for a particle trigger array. This strategy has been successfully pursued in the past with the Dutch LOFAR telescope, which made crucial contributions to the field of radio detection of cosmic particles. The applicants on this proposal played key roles in that project. To make the SKA observation campaign possible, an array of 96 particle detectors will be constructed. The individual detectors consist of scintillator plates (provided in-kind by the KIT), silicon photomultipliers, additional electronics and an RF shielded casing. DAQ and digitization is handled by standard SKA equipment. Design and construction of the array will be led by VUB. Our partners at KIT, Radboud University Nijmegen, and Curtin University will provide support in design, hardware, calibration and local deployment.