Coherent Cherenkov Radiation from Cosmic-Ray-Induced Air Showers

TL;DR

This paper proposes a new type of Cherenkov radiation, magnetically-induced, emitted by cosmic-ray air showers, which is collimated in a Cherenkov cone due to air's refractive index, and discusses its detection.

Contribution

It introduces the concept of magnetically-induced Cherenkov radiation from cosmic-ray air showers and suggests experimental methods for its detection.

Findings

The radiation is collimated in a Cherenkov cone due to air's refractive index.

The radiation's signature differs from traditional Cherenkov radiation.

Potential experimental verification methods are outlined.

Abstract

Very energetic cosmic rays entering the atmosphere of the Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of the Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a new effect: due to the index of refraction of air this radiation is collimated in a Cherenkov cone. To express the difference from usual Cherenkov radiation, i.e. the emission from a fast moving electric charge, we call this magnetically-induced Cherenkov radiation. We indicate its signature and possible experimental verification.