Accelerator measurements of magnetically-induced radio emission from particle cascades with applications to cosmic-ray air showers

摘要

For fifty years, cosmic-ray air showers have been detected by their radioemission. We present the first laboratory measurements that validateelectrodynamics simulations used in air shower modeling. An experiment at SLACprovides a beam test of radio-frequency (RF) radiation from charged particlecascades in the presence of a magnetic field, a model system of a cosmic-rayair shower. This experiment provides a suite of controlled laboratorymeasurements to compare to particle-level simulations of RF emission, which arerelied upon in ultra-high-energy cosmic-ray air shower detection. We comparesimulations to data for intensity, linearity with magnetic field, angulardistribution, polarization, and spectral content. In particular, we confirmmodern predictions that the magnetically induced emission in a dielectric formsa cone that peaks at the Cherenkov angle and show that the simulationsreproduce the data within systematic uncertainties.