X-ray Mirror Coatings for NewAthena: Updated Design, Development Status, and Performance

We present an overview of the development of the X-ray reflective coatings for the NewAthena mission based on the latest mission concept reported by the Science Re-definition Team (SRDT). The reflection of X-rays depends strongly on the material adopted as mirror coating, in this study we re-visit the material options as overcoat for Ir and trade-offs. Along with optimised expected performance based on single layer, bi-layer, tri-layer and multilayer coating designs, we also report on the latest experimental results on X-ray performance of the coatings deposited onto SPO plates by magnetron sputtering. X-ray reflectometry are presented and allow for characterisation of the X-ray mirrors and provide results on performance and stability.