New generation of 3D detectors for x-ray polarimetry: simulation of performances

A new generation of 3D gas detectors is available and applied today, for example, to track particles in accelerator vertex detectors. They apply the concept of Time Projection Chambers to 2D devices. When coupled with a gas system, Timepix3, or the most recent Timepix4, allows for 3D track reconstruction. Such capability promises to improve by far the sensitivity of the present 2D Gas Pixel Detector (GPD) on board the Imaging X-ray Polarimeter Explorer (IXPE), also solving the issue of its large dead time thanks to its parallel read-out. In this framework, we are developing a new simulation software based on the Geant4 tool to be used to develop these devices as a new generation of X-ray polarimeters for astrophysics. Moreover, a new read-out software capable of obtaining a 3D track reconstruction, taking advantage of the Timepix3 time capabilities and using the IXPE GPD legacy, has been developed, which helps improve the polarimetric sensitivity in view of future X-ray missions having on board this kind of detectors.