Air Shower Measurements with LOFAR

TL;DR

This paper discusses the use of LOFAR, a highly calibrated radio interferometer in Europe, for detecting and analyzing radio pulses emitted by cosmic ray air showers, aiming to improve detection and characterization methods.

Contribution

It introduces LOFAR's capabilities for studying radio emissions from air showers and proposes a new trigger method based on pulse shape analysis for real-time detection.

Findings

LOFAR can detect short radio pulses from air showers.

Pulse shape parameters help discriminate real events from interference.

A scintillator array will validate the radio trigger performance.

Abstract

Air showers from cosmic rays emit short, intense radio pulses. LOFAR is a new radio telescope, that is being built in the Netherlands and Europe. Designed primarily as a radio interferometer, the core of LOFAR will have a high density of radio antennas, which will be extremely well calibrated. This makes LOFAR a unique tool for the study of the radio properties of single air showers. Triggering on the radio emission from air showers means detecting a short radio pulse and discriminating real events from radio interference. At LOFAR we plan to search for pulses in the digital data stream - either from single antennas or from already beam-formed data - and calculate several parameters characterizing the pulse shape to pick out real events in a second stage. In addition, we will have a small scintillator array to test and confirm the performance of the radio only trigger.