Ice detectors listen to the radio voices of cosmic particles ⚡ экспресс
The ground-based neutrino observatories ARA and RNO-G aim to detect radio emission from particle cascades triggered by ultra-high-energy neutrinos, using antennas embedded in ice at the South Pole and in Greenland. Cosmic rays initiate similar showers, creating the main background. To characterize their radio signal, the FAERIE software suite was used, combining the CoREAS code for modeling radio emission in the atmosphere and GEANT4 for a detailed account of particle interactions in the ice. Polarization, temporal structure, total radiated energy, and their dependence on shower parameters were calculated. The obtained data will confirm the detection principle, calibrate the experimental setups, and improve the efficiency of separating neutrino signals from the cosmic-ray background.
Neutrinos are ghost particles: predicted by the Standard Model, they barely interact with matter. Catching them is like trying to hear a whisper in the roar of a waterfall. The ARA and RNO-G detectors, frozen into the ice of Antarctica and Greenland, act like ears, picking up radio bursts that race outward through the ice at the speed of light when a particle hits. Transparent to radio waves like glass to light, the ice allows the signal to be heard from kilometers away. But the roar isn't just from neutrinos: cosmic rays constantly bombard the Earth and produce similar bursts. To tune out this noise, physicists used the FAERIE simulation. It recreated a particle's path from the atmosphere to the glacier and described its 'signature': the direction of the radio waves, arrival time, and strength. The model ran for weeks on supercomputers, although the burst lasts billionths of a second. These data teach detectors not to confuse neutrinos with cosmic rays. Then the planet's radio ear will pick up the distant voices of black holes and stellar explosions, encoded in the radio spectroscopy of icy showers.
🎯 Antarctic ice at depths of 1–2 km is more transparent to radio waves than air: a signal can travel ten kilometers with almost no loss.