Alignment verification of the X-IFU Focal Plane Assembly detector stage in warm and cold conditions

This work describes the alignment verification test program performed on the X ray Integral Field Unit Focal Plane Assembly (X-IFU FPA) Development Model (DM). The alignment of the detector stage with respect to the external interfaces in warm conditions is verified by mechanical measurements on a 3D measurement machine. In addition relative movement of the detector stage compared to the outer structure is monitored in 5 Degrees Of Freedom (DoF) during several thermal cycles. The acquired data is compared to mechanical models using a rigid body transformation description. Finally, these results are used in the alignment strategy within the X-IFU FPA using the available alignment budget estimates.