Ph.d. degree
Budapest University of Technology and Economics, Hungary, 2021

Milán Klausz

Supervisor: Péter Zagyvai, Dávid Légrády, Richard Hall-Wilton

Full Simulation of Detector Performance of Neutron Instrumentation at ESS

Keywords:

• Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc)
• Neutron detectors (cold, thermal, fast neutrons)
• Gaseous detectors
• Instrumentation and methods for time-of-flight (TOF) spectroscopy

Abstract:

The European Spallation Source (ESS) is intended to become the most powerful spallation neutron source in the world and the flagship of neutron science in the upcoming decades. The exceptionally high neutron flux will provide unique opportunities for scientific experiments, but also set high requirements for the detectors. The primary purpose of this thesis is to estimate the incident and detection rates that are anticipated for two ESS instruments, namely LoKI and BIFROST. Full simulation models for both instruments from source to detector position are presented, implemented with the use of multiple software packages, namely Geant4, McStas, NCrystal and MCPL. A detailed Geant4 simulation study of the Boron-Coated Straws detector technology is also included, investigating various aspects of the detector performance, e.g. efficiency, activation, absorption and the impact of scattering on the measured signal.