Simulation of the optical performance of the Fluorescence detector Array of Single-pixel Telescopes

M Pech ,Xiaochen Ni,Toshihiro Fujii,John Farmer ,M Palatka ,P Hamal ,Petr Schovánek ,S B Thomas ,L Chytka ,Dušan Mandát ,J N Matthews ,L Nožka ,J A Bellido ,M Hrabovský ,P Privitera ,P Horváth ,Justin M Albury ,M Malacari ,P Trávníc̆ek

doi:10.1051/epjconf/201921005014

Abstract

The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a proposed large-area, next-generation experiment for the detection of ultra-high energy cosmic rays via the atmospheric fluorescence technique. The telescope’s large field-of-view (30 ×30) is imaged by four 200 mm photomultiplier-tubes at the focal plane of a segmented spherical mirror of 1.6 m diameter. Two prototypes are installed and taking data at the Black Rock Mesa site of the Telescope Array experiment in central Utah, USA. We present the process used for optimization of the optical performance of this compact and low-cost telescope, which is based on a simulation of the telescope’s optical point spread function.

Highlights

The origin of the ultra-high energy cosmic rays (UHECRs) is a hot topic in astrophysics
We present a groundbased fluorescence detector (FD) telescope concept which would fulfil these requirements
In this paper we present our approach to the design of this kind of fluorescence telescope taking into account current technological capabilities and optical simulations

Summary

Introduction

The origin of the ultra-high energy cosmic rays (UHECRs) is a hot topic in astrophysics. Large ground areas must be instrumented in order to collect enough statistics to advance the field, and the generation of detectors will require an aperture which is larger by an order of magnitude relative to the current generation experiments. This large area is essential, because the flux of particles with energies exceeding 1020 eV is lower than 1 particle/km2/century. The generation of experiments will require an aperture which is larger by an order of magnitude This may be accomplished by fluorescence detection of UHECRs with a giant ground array. Three prototype telescopes using this design are installed and fully functional at the Black Rock Mesa site of the Telescope Array experiment

FAST optical design

Optical design

FAST optical system simulation

Conclusion