X-Ray detector and method

We provide an x-ray detector having a housing with one or more internal surfaces defining an internal volume. The housing is adapted in use to contain a vacuum within the internal volume. An x-ray sensor is located within the internal volume of the housing. A window, located within the housing, is adapted to permit the passage through the window of x-rays to be detected from the external environment to the sensor. A getter material is applied as a coating to the one or more internal surfaces, for absorbing gaseous species present within the vacuum and for substantially preventing outgassing from the parts of the walls coated by the getter material.