Star-XP: A simulation framework for Polar-2/ low energy X-ray polarization detector

Star-XP is a simulation framework specifically designed for the Low Energy X-ray Polarization Detector (LPD) onboard the POLAR-2 mission. It is capable of simulating the emission of particles from given sources and the interaction of these particles with the detector model and the subsequent electronic readout of LPD. Traditional full simulations using Garfield++, Geant4, and finite element analysis are time-intensive and often overlook the influence of read-out electronics on the resulting output tracks. Star-XP addresses these limitations by incorporating a time evolution framework, and a fast simulation algorithm for photoelectron tracks is implemented on this framework. The simulated photoelectron tracks provided by Star-XP are consistent with experimental data in terms of eccentricity, circularity, energy spectrum, and other characteristics. These results demonstrate the relatively accuracy and efficiency of the software framework, making it a powerful tool for the development of gas polarimetry such as LPD.