The Lateral Distribution Function of Shower Signals in the Surface Detector of the Pierre Auger Observatory

TL;DR

This paper discusses the development and analysis of the lateral distribution function (LDF) for shower signals in the Pierre Auger Observatory's surface detector, crucial for estimating primary cosmic ray energies.

Contribution

It introduces a method to fit the LDF to detector data and evaluates various models using experimental and simulated data for improved energy estimation.

Findings

Preliminary LDF models examined using experimental data.

Monte Carlo simulations used to test LDF accuracy.

LDF fitting is essential for accurate primary energy determination.

Abstract

The surface detector (SD) array of the southern Pierre Auger Observatory will consist of a triangular grid of 1600 water Cherenkov tanks with 1.5 km spacing. For zenith angles less than 60deg the primary energy can be estimated from the signal S(1000) at a distance of about 1000m from the shower axis, solely on basis of SD data. A suitable lateral distribution function (LDF) S(r) is fitted to the signals recorded by the water tanks and used to quantify S(1000). Therefore, knowledge of the LDF is a fundamental requirement for determining the energy of the primary particle. The Engineering Array (EA), a prototype facility consisting of 32 tanks, has taken data continuously since late 2001. On the basis of selected experimental data and Monte Carlo simulations various preliminary LDFs are examined.