Using the Westerbork Radio Observatory to detect UHE cosmic particles interacting on the moon

摘要

Ultra-High-Energy (UHE) particles of cosmological origin (cosmic-rays and neutrinos), carry information on the most spectacular events known. These extremely energetic (energies larger than 1 ZeV = 10.(21) eV) cosmic-rays or neutrinos initiate in the lunar regolith a cascade of charged particles which acts as a radio pulse emitter. The instantaneous power produced can be detected here at the Earth, with a radio telescope operating at the optimal frequency window around 150 MHz. Using 12 telescopes of the Westerbork Synthesis Radio Telescope, WSRT, with a field of view covering the whole lunar surface, our calculations show that one should identify 10 UHE events within an observation time of 500 hours, assuming an extrapolated power law dependence of the highest ever measured cosmic-ray events, around an energy of 10(20) eV. A null result will determine unambiguously the GKZ effect for the cosmic-ray flux and improve the present world upper limit on the neutrino flux above I ZeV, by three orders of magnitude, allowing for the first time to test the Waxman-Bahcall neutrino flux limit.