Radar reflection off extensive air showers

J Stasielak,F Salamida,J Blümer,M Ludwig,T Huege,M Unger,J Wochele,S Baur,A Haungs,S Mathys,H Schieler,P Neunteufel,H Wilczyński,O Krömer,M Kleifges,R Šmída ,J Rautenberg ,M Riegel ,M Roth ,H O Klages ,Jan Pękala ,Karl-Heinz Kampert ,M Bertaina ,А Чиавасса ,F Werner ,M Weber ,R Engel

doi:10.1051/epjconf/20135308013

Abstract

We investigate the possibility of detecting extensive air showers by the radar technique. Considering a bistatic radar system and different shower geometries, we simulate reflection of radio waves off the static plasma produced by the shower in the air. Using the Thomson cross-section for radio wave reflection, we obtain the time evolution of the signal received by the antennas. The frequency upshift of the radar echo and the power received are studied to verify the feasibility of the radar detection technique.

Highlights

Traditional techniques of extensive air shower (EAS) detection include counting the shower particles at the ground level and measuring fluorescence light from the excited nitrogen in the atmosphere
We investigate the possibility of detecting extensive air showers by the radar technique
In this paper we investigate the possibility of detecting EAS by the bistatic radar system

Summary

INTRODUCTION

Traditional techniques of extensive air shower (EAS) detection include counting the shower particles at the ground level and measuring fluorescence light from the excited nitrogen in the atmosphere. The concept of detecting EAS using radar technique is based on the principle of scattering radio waves off the static plasma produced in the atmosphere by the energetic particles of the shower. If the local plasma frequency is lower than the frequency of the incoming radio wave, the region is underdense and the radio wave can penetrate the ionized region In such a case the reflections are caused by the Thomson scattering of the radio wave on individual free electrons. If we calculate the attenuation length of the radio wave in the plasma with frequency νp = 100 MHz and νp = 1 MHz one obtains ∼300 m and ∼3000 km, respectively Those lengths are much larger than the size of the overdense plasma, the radio wave can penetrate the whole volume of the plasma disk produced by the EAS. The final result will depend on the individual phase factors of the scattering electrons

RADAR REFLECTION

FREQUENCY UPSHIFT

DETAILS OF THE SIMULATION

POWER RECEIVED BY THE DETECTOR ANTENNA

RESULTS

CONCLUSIONS