The Energy Spectrum of a Radio Pulse Created by a Cascade Disk Within the Moon's Regolith

TL;DR

This paper analyzes the radio emission spectrum from a cascade disk within the Moon's regolith, revealing a sharp decline at high frequencies and emphasizing the need to adjust radio-frequency measurement windows for cosmic ray detection.

Contribution

It applies analytical solutions to determine the energy spectrum of radio pulses from cascade disks in lunar regolith, highlighting the impact of finite disk size on coherence and measurement accuracy.

Findings

Maximum spectrum at 0.5-0.6 GHz for a 0.06m disk radius

Spectrum drops by 5-6 orders at 2-2.5 GHz

Finite disk size causes loss of coherence affecting measurements

Abstract

Some known analytical solutions for a cascade shower were used for determining the intensity of excess electrons' radio-emission. It is shown that the energy spectrum has a sharp decline in the region of high frequencies. At a usual root-mean-square radius of the disk within the Moon's regolith ~ 0.06m the maximum of the spectrum is in the region ~ 0.5-0.6 GHz while in the range 2-2.5 GHz the pulse's amplitude drops by 5-6 orders. This fact is a consequence of loss of coherence due to finite dimensions of the cascade disk and demands conducting a significant correction of "radio-frequency window" for measuring cosmic rays' flux with a radio telescope.