Physics and electronics simulations of the Large Pixel Detector at EuXFEL

A simulation of the Large Pixel Detector (LPD), an X-ray pixel detector at EuXFEL, is presented. HPAD Output Response fUnction Simulator (HORUS) was written in IDL to model the Adaptive Gain Integrating Pixel Detector (AGIPD), another X-ray pixel detector at EuXFEL; HORUS_LPD is an adaptation of the code to model LPD. While the original program was intended and designed to be modular, the large differences in the architecture of the Front End Modules (FEMs) in AGIPD and LPD required most of the code to be rewritten, particularly the triple amplification used by LPD. The program simulates from the absorption of photons in the silicon to the final readout image and all sources of noise expected in the real system. The simulation is written in Interactive Data Language (IDL), a programming language specifically intended for working with images or large arrays, functionality that is utilized by HORUS and HORUS_LPD. The simulation was tested using example data and an analysis of the noise in LPD was conducted.