Geant4 simulation of sFLASH experiment

Abstract

The goal of Super Fluorescence Air SHower (sFLASH) is to reduce the current fluorescence yield systematic uncertainty to improve energy measurement of ultra-high energy cosmic rays. The experiment was performed at SLAC National Accelerator Laboratory to measure the air fluorescence yield from extensive air showers. A set of alumina bricks is placed in front of the beam pipe as the target to generate a cascade in the bricks. When the charged particles of cascade escape from the target, they excite the air molecules and emit the fluorescence. Several photon multipliers collect the fluorescence in the dark room to estimate the fluorescence yield. In this simulation, the proper geometry of this experiment is built with Geant4, which is the simulation toolkit for high energy particle interactions.