Measuring polarization in the X-ray range: New simulation method for gaseous detectors

In the last few years, many experimental groups developed new instruments to measure linearly polarized X-rays in the energy range of few keV where the dominant interaction process with matter is the photoelectric effect. These instrumental setups are principally based, on micro-pattern gas detectors that are able to measure the photoelectron tracks. detectors are characterized by many parameters that influence their performance, for example, the gas mixture, the gas pressure, the pitch dimension, the gas electron multiplier (GEM) voltage, etc. Carlo simulations are useful tools to improve these parameters. The Geant4 toolkit has the ability to take into account many detector characteristics. s work, we suggest Geant4 as a useful toolkit to simulate the photoelectric interaction of linearly polarized X-rays. In particular, we have developed a new calculation of the final state, properly taking into account the direction of the photo-electron. We simulate two experimental setups found in the literature and show that the simulation results obtained are in agreement with the experimental data.