Since 2013, the Antarctic neutrino telescope IceCube has been detecting neutrinos that come from deep space. However, IceCube struggles to detect neutrinos with energies above 10¹? electronvolts because of the extremely low flux of these neutrinos at Earth. Now, researchers have obtained the first measurements of "radar echoes" from high energy particle cascades using a high energy electron beam at the SLAC National Accelerator Laboratory. Radar echoes are radio waves reflected from a conducting surface. Cascades occur when an ultra high energy particle interacts with material, producing other particles that move at roughly the speed of light and ionizing the material. By bouncing radio waves off that ionization, Prohira et al. created a detectable radar echo that can be used to detect the cascade itself. The new radar echo detection method could help scientists create a neutrino telescope complementary to existing technology in the detection of high energy neutrinos.
Observation of Radar Echoes From High-Energy Particle Cascades
Steven Prohira et al.